Search

[Display omitted] • A comprehensive overview of atomically dispersed M−N−C catalysts for ORR. • Focus on active site engineering to improve activity and stability in fuel cells and Zn-air batteries. • Future directions of developing advanced M−N−C catalysts for ORR are outlined. Atomically dispersed metal-nitrogen-carbon (M−N−C) oxygen reduction reaction (ORR) catalysts have been proven as one of the most promising non-precious metal catalysts. In this review, we summarize recent advances in the active site engineering toward M−N−C catalysts for ORR, which focuses on modulating coordination environment of active sites to enhance intrinsic activity, such as coordination structures, heteroatomic doping M−N−C, dual-atom sites, coupled catalytic sites, and defective M−N−C. Moreover, the strategies for increasing the density and utilization of active sites are discussed, including chelation, stepwise atom doping, spatial confinement, surface exposed M−N x sites, and porous structure optimization. Thereafter, the performance decline mechanisms are introduced and the strategies for improving stability are systematically analyzed by regulating the structure of the active center and carbon support. Finally, we also proposed the future perspectives of M−N−C catalysts. This review aims to provide some guidelines towards synthesis of M−N−C catalysts for fuel cells and Zn-air batteries. [ABSTRACT FROM AUTHOR]

Lung cancer is the most common type of cancer worldwide, the most prevalent form of which is non-small cell lung cancer (NSCLC). MicroRNAs (miRs) are involved in the progression of NSCLC; however, the specific function of miR-140-5p in NSCLC remains unclear. The present study demonstrated that miR-140-5p was downregulated in the tumor tissues of patients with NSCLC, and it was associated with a poor prognosis. Furthermore, miR-140-5p significantly suppressed cell migration and invasion of the NSCLC cell line A549. In addition, the direct regulatory effect of miR-140-5p on vascular endothelial growth factor-A (VEGFA) was predicted by TargetScan and verified using a luciferase reporter gene assay. The present study also hypothesized that miR-140-5p may inhibit the expression of phosphorylated-protein kinase B by targeting VEGFA. In conclusion, miR-140-5p may be a potential target for the development of anti-neoplastic therapies in lung cancer. [ABSTRACT FROM AUTHOR]

Nanocrystalline Ni-Mo alloy coatings with excellent brightness, high hardness, and corrosion resistance were prepared. Nanocrystalline Ni-Mo alloy coating with a Mo content of 14.94 at% was electrodeposited on the copper foil substrate under the optimized conditions with the current efficiency of 51.64%. The electrodeposition behavior of Ni-Mo alloy coatings was studied by cathodic polarization curve and chronopotentiometry. Chronopotentiometry showed that the nucleation rate of Ni-Mo alloys can be accelerated with the increase of current density. Meanwhile, the cathodic polarization curves show that the additives can effectively inhibit the electrodeposition of Ni-Mo alloys. The (2 0 0) and (2 2 0) diffraction peaks of Ni gradually disappeared and the grain size gradually decreased with the increase of Mo content in the alloy coating according to XRD and TEM analysis. Scanning electron microscope (SEM) and confocal microscope observation results show that the coating becomes smoother and denser with the increase of Mo content when Mo content was lower than 14.94 at%, after which the density of the coating saw a decline due to the intensified hydrogen evolution reaction. The microhardness results of the alloy coating show that the microhardness of the alloy coating is related to the solid solution strengthening, texture evolution, and plastic deformation of the alloy. Meanwhile, the alloy coating has a Hall-Petch relationship and inverse Hall-Petch relationship, and the critical grain size is 5.5 nm. The corrosion resistance of Ni-Mo alloy coating is better than that of pure Ni coating, and the corrosion resistance is optimal when the Mo content is about 15 at%. In addition, in the plating solution containing additives, the deposited Ni-Mo alloy coating is smoother and denser, and the hardness and corrosion resistance of the alloy coating is also greatly improved. [Display omitted] • The minimum grain size of nanocrystalline Ni-Mo alloy coatings can reach 2.7 nm. • The hardness and corrosion resistance of nanocrystalline Ni-Mo alloy coatings are higher than pure Ni coatings. • Composite additives can significantly increase Ni-Mo alloy polarization. [ABSTRACT FROM AUTHOR]

Solvent environment engineering is developed to synthesize ZIF-derived hierarchically porous cubic Fe N C(C) catalysts with densely Fe-N x sites. [Display omitted] • The Fe-N x site density of ZIF-derived Fe N C is controlled by changing the solvent. • The Fe N C(C) synthesized in water has a high single Fe atom loading (0.6 at%). • The catalyst displays satisfactory ORR activity under alkaline/acidic environment. • The catalyst presents nice performance in liquid and solid-state Zn-air batteries. Zeolitic imidazole framework (ZIF)-derived iron–nitrogen-carbon (Fe N C) materials are expected to be high-efficiency catalysts for oxygen reduction reaction (ORR). However, increasing the density of active sites while avoiding metal accumulation still faces significant challenges. Herein, solvent environment engineering is used to synthesize the Fe N C containing dense Fe-N x moieties by adjusting the solvent during the ZIF precursor synthesis process. Compared with methanol and water/methanol, the aqueous media can provide a more moderate Fe content for the ZIF precursor, which facilitates the construction of high-density Fe-N x sites and prevent the appearance of iron-based nanoparticles during pyrolysis. Therefore, the Fe N C(C) nanocubes synthesized in an aqueous media have the highest single atom Fe loading (0.6 at%) among the prepared samples, which presents excellent oxygen reduction properties and durability under alkaline and acidic conditions. The advantage of Fe N C(C) is proven in Zn-air batteries, with outstanding performance and long-term stability. [ABSTRACT FROM AUTHOR]

[Display omitted] Enhancing the electrocatalytic oxygen evolution reaction (OER) performance is essential to realize practical energy-saving water electrolysis and CO 2 electroreduction. Herein, we report a bimetallic co-doping engineering to design and fabricate nickel–cobalt-iron collaborative oxy-hydroxide on nickel foam that labeled as NiCoFeO x H y -NF. As expected, NiCoFeO x H y -NF exhibits an outstanding OER activity with current density of 10 mA cm−2 at 194 mV, Tafel slope of 53 mV dec−1, along with the robust long-term stability, which is significantly better than bimetallic NiCo and NiFe combinations. Comprehensive computational simulations and characterizations jointly unveil that the twisted ligand environment induced by heteroatoms ensures the balance strength between the metal–oxygen hybrid orbital states and the oxidized intermediates adsorption, thus lowering the oxygen cycling energy barriers for overcoming the sluggish OER kinetics. Moreover, a novel phase transition behavior is monitored by in-situ Raman spectra under OER operating conditions, which facilitates electron-mass transfer as well as boosts the exposure of activity sites. For practical applications, Ni 2 P-NF || NiCoFeO x H y -NF and Cu || NiCoFeO x H y -NF couples were constructed to realize high-efficiency water electrolysis and CO 2 electrochemical reduction for the production of valuable H 2 and C 2 H 4 , respectively. This work elucidates a novel mechanism by which bimetallic co-doping improves the electrocatalytic OER activity of nickel-based hydroxides. [ABSTRACT FROM AUTHOR]

Abstract: Gel-type polymer electrolytes with 1-butyl-4-methylpyridinium bis(trifluoromethanesulfonyl)imide (B4MePyTFSI) ionic liquid are formed by the solution casting method. The conductivity and transference number measurements are carried out to investigate conductivity and charge transport in the gel polymer electrolytes. The conductivity of the samples increases when the amount of B4MePyTFSI ionic liquid is increased. The lithium ion ionic conductivity reaches the maximum value (2.01×10−4 S cm−1) when GPE contains 33.3 wt% B4MePyTFSI. The electrochemical stability window of ILGPE is about 5.5V versus Li+/Li at 20°C, meeting the basic requirement of rechargeable lithium batteries. Discharge performance of lithium battery using this ILGPE membrane shows a capacity of about 160 mAh g−1. The excellent performance with higher capacity, good cycle stability and compatibility are observed for the Li/ILGPE/LiFePO4 cells. The interfacial resistances between ILGPE and electrodes have the less change after 10 cycles. [Copyright &y& Elsevier]

Abstract: Electrodeposition of Cu–Li alloy from 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIm][BF4]) ionic liquid was investigated. The cyclic voltammetry behaviors of [BMIm][BF4] containing Cu(II), Li(I), and mixtures of Cu(II) and Li(I) were studied at a copper working electrode, separately. The Cu–Li alloy produced by direct current electrodeposition was characterized by inductively coupled plasma atomic emission spectrometry (ICP), X-ray photoelectron spectroscopy (XPS), and scanning electron microscope (SEM). The function of 2-butyne-1,4-diol was studied by linear sweep voltammetry. The result shows that the 2-butyne-1,4-diol could improve Li content in deposit, and make the Cu–Li alloy deposits denser and finer. [Copyright &y& Elsevier]

Abstract: Ionic liquid gel polymer electrolyte (ILGPE) based on N-methyl-N-butylpiperidinium-bis(trifluoromethanesulfonyl)imide (PP14TFSI), bis(trifluoromethanesulfonyl)imide lithium salt (LiTFSI) and poly(vinylidene difluoride-co-hexafluoropropylene) (P(VdF-HFP)) is prepared for lithium ion batteries by solution casting. The ILGPE is characterized by scanning electron microscopy (SEM), thermogravimetry (TG) and electrochemical tests. The results indicate that the addition of PP14TFSI to the P(VdF-HFP)–LiTFSI polymer electrolyte leads to 3-dimensional network structures, and the ILGPE is stable below 150°C and will not decompose until 310°C without considering the volatilizing of the residual solvent. The ionic conductivity increases with the temperature rising, and the ionic conductivity is 0.23×10−3 Scm−1 and 2.1×10−3 Scm−1 at 20°C and 80°C, respectively. The electrochemical window is −0.15 to 4.85V vs. Li+/Li, which is wide enough to be used with common electrode materials. Battery tests show that the ILGPE is stable even at 80°C when operated in Li/LiFePO4 batteries, and Li/LiFePO4 batteries with the gel polymer electrolyte exhibit good cycling performance at 60°C at 1C current rate. The discharge capacity was 131.01mAhg−1 after 100 cycles with 90% capacity retention. [Copyright &y& Elsevier]

Abstract: Gel polymer electrolytes containing 1-ethyl-3-methylimidazolium-bis (trifluoromethyl-sulfnyl)imide (EMITFSI) ionic liquid were prepared for lithium ion batteries by solution casting method. Thermal and electrochemical properties have been determined for the gel polymer electrolytes. Proper addition of EMITFSI to the P(VdF-HFP)-LiTFSI polymer electrolyte improves the ionic conductivity and electrochemical window to 2.11 × 10−3 S cm−1 (30 °C) and 4.6 V. In combination of the prepared ternary P(VdF-HFP)-LiTFSI-EMITFSI ionic liquid polymer electrolytes, Li4Ti5O12 anode exhibited two extra voltage plateaus around 1.1 V and 2.3 V except the typical voltage plateau around 1.6 V by possible side reaction between ionic liquid and polymer. LiFePO4 cathode exhibited high capacity above 140 mA h g−1 and retention of 93.1% due to the suppressed polarization effect caused by enhanced ion transport properties. The high temperature of 80 °C didn''t have significant impact on the cycling performance. [Copyright &y& Elsevier]

Abstract: Porous anodic alumina template is synthesized by electrochemical anodization of aluminum and used to grow cobalt nanowires. The cobalt nanowires produced by direct current electrodeposition are characterized by field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction and physical property measurement system. Test results indicate that the average diameter of cobalt nanowires is about 45nm, which is generally the same as the pore diameter of porous anodic alumina template, and the cobalt nanowires electrodeposited from mixture of 1-ethyl-3-methylimidazolium chloride ionic liquid and ethylene glycol have a smoother surface and better magnetic properties than cobalt nanowires electrodeposited from aqueous solution, and they show a better squareness. Therefore it can be concluded that the cobalt nanowires electrodeposited from mixture of 1-ethyl-3-methylimidazolium chloride ionic liquid and ethylene glycol using porous anodic alumina template can be used as a perpendicular magnetic recording film. [Copyright &y& Elsevier]

Heteroatoms-modified Fe–N–C catalysts have garnered significant attention for enhancing the oxygen reduction reaction (ORR). However, revealing the correlation between the type of heteroatoms used for doping and catalytic performance still faces significant challenges. Herein, based on the density functional theory (DFT), a series of heteroatom-modified Fe–N–C models with the tailored Fe–N 4 -X (X = S, P or B) site are constructed to explore the regulatory mechanism of heteroatoms on the electronic structure and adsorption behavior of Fe centers. Theoretical calculations reveal that the doping of S atoms can optimize the electronic environment of Fe atoms, thus leading the favorable interaction between Fe–N 4 –S site and OH intermediates. As a result, the Fe–N 4 –S site possess a lower energy barrier for the desorption of OH* than that of Fe–N 4 –B and Fe–N 4 –P, indicating higher catalytic activity and kinetics of S-modified Fe–N–C catalysts. [Display omitted] • Heteroatom-modified Fe–N 4 models are analyzed by theoretical calculations. • S doping can optimize the electronic structure around Fe–N 4 sites. • S doping promotes the OH* desorption, thus leading to enhanced kinetics process. • Fe–N 4 –S model exhibits higher activity and stability than Fe–N 4 –B and Fe–N 4 –P. [ABSTRACT FROM AUTHOR]

[Display omitted] Copper-based tandem catalysts are effective candidates for yielding multi-carbon (C2+) products in electrochemical reduction of carbon dioxide (CO 2 RR). However, these catalysts still face a significant challenge regarding in the low selectivity for the production of a specific product. In this study, we report a high selectivity of 77.8 %±2 % at −1.0 V (vs RHE) for the production of C 2 H 4 by using a Cu 88 Ag 12 NW catalyst which is primarily prepared through a combined Cu-Ag co-deposition and wet chemical method, employing an attractive strategy focused on regulating the microenvironment over Cu-Ag nanowires. The experimental and computational studies show that the higher *CO coverage and lower intermediate adsorption energy are important reasons for achieving the high C 2 H 4 selectivity of Cu 88 Ag 12 NW catalyst. Comsol simulation results indicate that dense nanowires exhibit a nano-limiting effect on OH− ions, thereby leading to an increase in local pH and promoting coupling reactions. The catalyst demonstrates no noticeable decrease in current density or selectivity even after 12 h of continuous operation. The Cu-Ag nanowire composite exhibits remarkable catalytic activity, superior faradaic efficiency, excellent stability, and easy synthesis, which highlights its significant potential for electro-reducing carbon dioxide into valuable products. [ABSTRACT FROM AUTHOR]

The Zn-air battery is a promising next-generation battery because of the higher energy density and safety compared with the Li-ion battery. However, the Zn-air battery suffers from huge energy loss and poor cycling performance, which are due to the sluggish kinetics of oxygen reduction/evolution reactions (ORR/OER) and the instability of bifunctional catalysts. The state-of-the-art bifunctional catalyst is the composite of Pt and Ir/Ru oxides, which is hindered by the scarce resource and high cost. Therefore, developing low-cost and high-efficient bifunctional non-noble metal-based catalysts is essential to the deployment of Zn-air batteries. Herein, we report a dual-nitrogen-source mediated pyrolysis route to rationally design and synthesize the hybrid Co/Co–N–C bifunctional catalyst. The tailored catalyst consisting of carbon confined Co nanoparticles and atomically dispersed Co–N–C moiety is identified. Remarkably, the dual-nitrogen-source derived Co/Co–N–C catalyst demonstrates excellent electrochemical performances with a half-wave potential of 0.882 V for ORR and a potential of 1.640 V at 10 mA cm−2 for OER; reasonably, the bifunctionality of Co/Co–N–C, which is supported by the excellent self-breathing Zn-air battery performance (the maximum energy density of 897.1 Wh kg Zn −1; no obvious degradation within 167h cycling). The abundant Co-Nx sites and metallic Co nanoparticles synergistically boost the ORR and OER. Image 1 • A dual-nitrogen-source method is proposed to synthesize porous Co-based catalysts. • The dual nitrogen sources play different roles in morphology and structure control. • The hybrid carbon-confined Co nanoparticles and Co-N x sites are well tailored. • The good bifunctionality is due to the hybrid active site configuration. • Excellent performance and lifetime are obtained in a Zn-air battery. [ABSTRACT FROM AUTHOR]

Summary: This work introduces a method for measuring the main physical quantities, such as short‐circuit current and capacity loss, in the thermal runaway process of the parallel battery module and presents detailed analysis and discussion on a 25 Ah commercial prismatic lithium‐ion ferrous phosphate (LFP) battery. By establishing a basic circuit model of the thermal runaway process of the parallel battery module, experiments were conducted to observe the thermal runaway process of the parallel battery module. The parameters related to the electrothermal effect in the thermal runaway process were obtained by either direct measurement or calculation. The results showed that the short‐circuit resistance of the cell, which was triggered to thermal runaway changed dramatically. The minimum resistance was about 0.5 mΩ, and the peak current of discharge was more than 1100 A. During the stable discharge process of the other parallel cells to the thermal runaway cell, the short‐circuit resistance was about 10 mΩ. In the stable discharge stage, the electric heating power was about 600 to 900 W. However, the power of thermal runaway reaction from the cell itself was still more than 30 times the heating power of the electrothermal effect, exceeding 21 kW. The accuracy of the measurement method and analysis method was also verified by comparing the same parametric data obtained using different methods. The results showed that the method is feasible for studies on the mechanism and simulation of thermal runaway of parallel battery modules. [ABSTRACT FROM AUTHOR]

Coordination environment engineering is developed to synthesize Fe SA /NSC catalysts with the tailored N, S co-coordinated Fe atomic site. [Display omitted] • The Fe-N 3 S active site with the optimized electronic structure is constructed. • S doping promotes the OH* desorption, thus leading to enhanced kinetics process. • The catalyst displays impressive ORR activity in both alkaline and acidic mediums. • The catalyst exhibits excellent performance in Zn-air batteries and fuel cells. Atomically dispersed iron–nitrogen-carbon (FesbndNsbndC) materials have been considered ideal catalysts for the oxygen reduction. Unfortunately, designing and adjusting the electronic structure of single-atom Fe sites to boost the kinetics and activity still faces grand challenges. In this work, the coordination environment engineering is developed to synthesize the Fe SA /NSC catalyst with the tailored N, S co-coordinated Fe atomic site (Fe-N 3 S site). The structural characterizations and theoretical calculations demonstrate that the incorporation of sulfur can optimize the charge distribution of Fe atoms to weaken the adsorption of OH* and facilitate the desorption of OH*, thus leading to enhanced kinetics process and intrinsic activity. As a result, the S-modified Fe SA /NSC exhibits outstanding catalytic activity with the half-wave potentials (E 1/2) of 0.915 V and 0.797 V, as well as good stability, in alkaline and acidic electrolytes, respectively. Impressively, the excellent performance of Fe SA /NSC is further confirmed in Zn-air batteries (ZABs) and fuel cells, with high peak power densities (146 mW cm−2 and 0.259 W cm−2). [ABSTRACT FROM AUTHOR]

[Display omitted] • HP-Fe-N-C/2 exhibits eminent ORR activity and stability in alkaline and acidic media. • The Zn-air battery shows high power density and superior cyclability for 1342 h. • The power density of HP-Fe-N-C/2-based PEM fuel cell is up to 0.66 W cm−2. Atomically dispersed Fe-N-C catalysts are a promising alternative to platinum group metal (PGM) catalysts for oxygen reduction reaction (ORR). However, attaining efficient ORR activity and superior stability in Fe-N-C catalysts is still crucial yet challenging. Herein, we report a rational SiO 2 -mediated two-step pyrolysis strategy for stabilizing densely exposed Fe-N 4 active sites on hierarchically porous carbon (HP-Fe-N-C/2). Benefiting from the high density of accessible Fe-N 4 sites and the high graphitization degree of carbon support, the obtained HP-Fe-N-C/2 catalyst demonstrates outstanding activity and stability for ORR in both alkaline and acidic media. When used as the cathode catalyst, the assembled Zn-air battery shows a high peak power density of 217 mW cm−2 and ultra-long cycling stability for 1342 h without noticeable degradation. As a PGM-free cathode in proton exchange membrane fuel cells, it delivers a maximum output power density of 0.66 W cm−2. [ABSTRACT FROM AUTHOR]

[Display omitted] • A Zn 5 (OH) 6 (CO 3) 2 -assisted pyrolysis strategy is proposed to prepare a coupled catalyst. • Fe nanoparticles can optimize electronic structures and d-band center of Fe center. • Fe-FeN-C exhibits eminent ORR activity with a E 1/2 of 0.921 V in alkaline media. • The Zn-air batteries deliver high power density and long-cycle life for 408 h. Fe single-atom catalysts still suffer from unsatisfactory intrinsic activity and durability for oxygen reduction reaction (ORR). Herein, the coexisting Fe single atoms and nanoparticles on hierarchically porous carbon (denoted as Fe-FeN-C) are prepared via a Zn 5 (OH) 6 (CO 3) 2 -assisted pyrolysis strategy. Theoretical calculation reveals that the Fe nanoparticles can optimize the electronic structures and d-band center of Fe active center, hence reducing the reaction energy barrier for enhancing intrinsic activity. The Zn 5 (OH) 6 (CO 3) 2 self-sacrificial template not only can promote the formation of Fe single atoms, but also contributes to the construction of microporous/mesoporous/macroporous structures. Therefore, the obtained Fe-FeN-C exhibits impressive ORR activity with a half-wave potential of 0.921 V, which far exceeds Pt/C. With Fe-FeN-C as the cathode catalyst, the assembled Zn-air batteries delivered a maximum power density of 206 mW cm−2 and a long-cycle life over 400 h. [ABSTRACT FROM AUTHOR]

Highlights: A promising solar-powered environmentally friendly process for the synthesis and application of catalysts for hydrogen evolution reaction has been proposed. A delicate NiCo(OH)x-CoyW catalyst with a bush-like heterostructure was realized via gas-template-assisted electrodeposition, followed by electrochemical etching process. The excellent catalytic effect of NiCo(OH)x-CoyW for the hydrogen evolution reaction was systematically investigated through various physical and electrochemical analyses.To achieve high efficiency of water electrolysis to produce hydrogen (H2), developing non-noble metal-based catalysts with considerable performance have been considered as a crucial strategy, which is correlated with both the interphase properties and multi-metal synergistic effects. Herein, as a proof of concept, a delicate NiCo(OH)x-CoyW catalyst with a bush-like heterostructure was realized via gas-template-assisted electrodeposition, followed by an electrochemical etching-growth process, which ensured a high active area and fast gas release kinetics for a superior hydrogen evolution reaction, with an overpotential of 21 and 139 mV at 10 and 500 mA cm−2, respectively. Physical and electrochemical analyses demonstrated that the synergistic effect of the NiCo(OH)x/CoyW heterogeneous interface resulted in favorable electron redistribution and faster electron transfer efficiency. The amorphous NiCo(OH)x strengthened the water dissociation step, and metal phase of CoW provided sufficient sites for moderate H immediate adsorption/H2 desorption. In addition, NiCo(OH)x-CoyW exhibited desirable urea oxidation reaction activity for matching H2 generation with a low voltage of 1.51 V at 50 mA cm−2. More importantly, the synthesis and testing of the NiCo(OH)x-CoyW catalyst in this study were all solar-powered, suggesting a promising environmentally friendly process for practical applications. [ABSTRACT FROM AUTHOR]

BMIm-OTF (1-Butyl-3-methylimidazolium trifluoromethanesulfonate) ionic liquid and alcohols/different volume fraction of n -propyl alcohol (normal propyl alcohol) mixed electrolytes are studied for the first time. The electrochemical behaviors of CIGS are investigated by cyclic voltammetry (CV) in ionic liquid and alcohols mixed electrolytes, respectively. The morphological properties of CIGS films are detected using scanning electron microscopy (SEM). Raman spectra at around 175 cm − 1 are normalized to the dominant A 1 mode. The structural properties and various phases are determined by using X-ray diffraction (XRD) and Raman techniques. The XRD results indicate that the CIGS phase formed by incorporating Ga into the CIS phase. The Cu 1.00 In 0.45 Ga 0.1 Se 2.26 thin films present as a p-type semiconductor and the Ga/(Ga + In) = 0.18 which electrodeposited from BMIm-OTF/ n -propyl alcohol (30 vol%) mixed electrolytes. The band gap of the obtained CIGS thin film is approximately 1.48 eV, as measured using UV–visible absorption spectra. The carrier concentration and average Hall coefficient of the CIGS thin films are 6.366 × 10 19 cm − 3 and 9.806 × 10 − 2 cm 3 /C, respectively. [ABSTRACT FROM AUTHOR]

N-doped carbon materials are considered as one of the most promising alternatives for oxygen reduction reaction (ORR). However, they are usually limited due to their low porosity and low active N content. Here, we use adenine as a nitrogen-doped carbon (NC) precursor and the NaCl and ZnCl2 mixed molten salt as a template, and show that the pore structure of carbon materials can be controlled by adjusting the pyrolysis temperature, facilitating the exposure of active sites and improving the graphite-N content. Experiments showed that SZ-NC-900 (where S represents sodium chloride, Z represents zinc chloride) had a hierarchical porous structure (specific surface area was 2710.58 m2 g−1) and high N-doping content (8.93%). Therefore, it exhibited comparable ORR activity in alkaline medium (half wave potential was 0.856 V versus reversible hydrogen electrode). After 5000 cycles, the half-wave potential of SZ-NC-900 shifted only 1.4 mV compared with Pt/C (53 mV). In addition, the zinc–air battery (ZAB) prepared with SZ-NC-900 as the catalyst was superior to the Pt/C-based ZAB, further proving its application value. [ABSTRACT FROM AUTHOR]

Uniform electrodeposition of through-hole (TH) with a high aspect ratio is the key to the reliability of printed circuit board (PCB) interconnection. Inhibitors produce stronger inhibition at high potentials during TH electrodeposition and thus reduce the difference in electrodeposition rates between inside and outside the TH. In this paper, the electrochemical behavior of an ethylene oxide propylene oxide random copolymer (EO-PO) as an inhibitor on the cathode during periodic pulse reverse (PPR) electrodeposition was systematically studied. The results show that EO-PO will rotate under the effect of reverse pulse, and adsorb more strongly on the cathode surface, which inhibits the "cathode stripping" process of the reverse pulse. Through the electrodeposition experiments, compared with direct current (DC) electrodeposition, the PPR method effectively eliminates the copper nodule and improves the concentration window of EO-PO. The results pave the way for regulating and controlling TH electrodeposition with other additives. [Display omitted] [ABSTRACT FROM AUTHOR]

Searching for ideal candidates with high electrocatalytic performance for both HER and OER is a major objective to realize the large-scale H 2 production by seawater electrolysis. Herein, we report delicate, heterostructured NiTe-NiCoN and NiTe-NiFeN electrocatalysts, which exhibit outstanding HER and OER performance, respectively. Impressively, the NiTe-NiCoN || NiTe-NiFeN couples in alkaline seawater solution delivered 400 mA cm−2 at 1.84 V along with long-term stability. Further analysis has revealed that not only heterogeneous interface engineering ensures exposure of abundant active sites and faster electron-mass transfer, but also induces electron modulation that optimizes the absorption/desorption for the reaction intermediates to enhanced the intrinsic activity. Notably, a high electric field intensity generated by the nanosheet-nanorod structure induces a local "hydroxide enrichment" environment that promotes the OER kinetics. This work shed lights on these novel heterostructured electrocatalysts with strong synergy, while demonstrating the key role of the unique nanostructures in high-efficiency seawater electrolysis. [Display omitted] • NiTe-NiCoN and NiTe-NiFeN with core-shell nanorod arrays ensure a high active area, good electrical conductivity and seawater corrosion resistance. • Electronic modulation to enhance the intrinsic activity is achieved through interfacial synergy between metal nitrides and nickel telluride. • The nanostructure-induced "hot spots" effect modulates the electric field state to promote seawater OER kinetics and suppress the side effects of chlorine. [ABSTRACT FROM AUTHOR]

The inhibitory effect of molecular weight (Mw) of polyethylene glycol (PEG) on the through-hole filling by copper electroplating was investigated by the electrochemical testing method and energy change with DFT. The cathodic polarization, electron transfer resistance, and diffusion coefficient of PEG with different Mw and concentration were assayed by cyclic voltammetry and electrochemical impedance spectroscopy; The inhibitory effect of different PEG Mw was demonstrated and examined by cross-sectional images using OLYMPUS confocal laser microscope, and the thickness of the copper layer and TP value were important measurement standards. The adsorption behavior on copper surfaces was calculated using the first principles. As PEG Mw and concentration are increased, the best TP value and diffusion coefficient of the plating formula is gained when PEG Mw and concentration are 20000 g/mol and 250 mg/L, they are 148.56% and 2.34 × 10-7, respectively. Better adsorption energy can be obtained as the adsorption sites of PEG increases, and the adsorption energy of PEG5 is − 1.99 eV. The experimental and theoretical results show that PEG with small Mw has no inhibitory effect, and even accelerates the deposition rate of Cu2+/1+. Only when the Mw and concentration exceed 2000 g/mol and 150 mg/L, PEG can inhibit the deposition of Cu2+/1+, and the best effect of through-hole electroplating is 20000 g/mol and 250 mg/L. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Adsorption-coordination mechanism was calculated by quantum chemistry to demonstrate the inhibition effect of MG. • Adsorption-transport mechanism was illustrated to explain the bottom-up growth of cobalt under the influence of MG. • The nucleation and growth of cobalt is 3D diffusion-controlled progressive nucleation process. A novel suppressor, malachite green, was used to achieve bottom-up growth of cobalt in this work. Electrostatic potential, HOMO/LUMO of malachite green was calculated to provide an insight into the interaction between malachite green and metal substrate, while charge distribution, AIM (atoms in molecules theory) analysis and IRI (interaction region indicator) analysis were coupled to analyze the interaction between malachite green and cobalt ions. Adsorption-coordination inhibition mechanism was illustrated to explain the inhibition effect of malachite green. Electrochemical analysis was applied to evaluate malachite green. Cyclic voltammetry was used to confirm the inhibition effect of malachite green, while EQCM analysis demonstrates that the current efficiency was lowered by MG. The nucleation and growth of cobalt is 3D diffusion-controlled progressive nucleation growth under the influence of hydrogen evolution reaction and the compact cobalt coatings could be obtained by surface analysis. The effective MG concentration gradient could be formed within blind vias according to current transient analysis so as to develop electroplating rate difference. The bottom-up growth of cobalt within blind vias was achieved by carrying out electroplating test and the adsorption-transport mechanism was proposed to explain the superconformal electrodeposition of cobalt under the influence of MG. [ABSTRACT FROM AUTHOR]

Atomically dispersed iron-nitrogen-carbon catalysts offer great potential in oxygen reduction reaction (ORR), yet the poor exposure and low density of Fe-N x sites causes relatively low ORR activity. Herein, a zinc-assisted MgO template strategy is reported to construct porous carbon-supported Fe-N 4 sites (Fe-N-C). Iron atoms surrounded by zinc species are converted to abundant Fe-N 4 sites rather than Fe containing nanoparticles. Meanwhile, both the zinc species and the MgO template can effectively produce porous structure so as to increase the utilization of Fe-N 4 sites. Fe-N-C achieves superior ORR performance and stability in alkaline medium. Theoretical calculations manifest that Fe-N 4 sites can narrow the energy barrier for ORR. Moreover, finite element simulation exhibits the porous framework in Fe-N-C could significantly accelerate the diffusion of O 2. Therefore, Fe-N-C provides a high peak power density and superior discharge ability toward Zn-air batteries. [Display omitted] • Atomically dispersed Fe-N-C are prepared by zinc-assisted template strategy. • High density of Fe-N x and hierarchical porosity boost oxygen reduction reaction. • The porous framework of Fe-N-C could significantly accelerate the diffusion of O 2. • The catalyst exhibits an excellent performance in Zn-air batteries. [ABSTRACT FROM AUTHOR]

The reasonable design of porous structures is important but usually overlooked for nonprecious metal ORR catalysts. In this study, a facile dual melt-salt-mediated templating method is developed to prepare a Fe-N-C catalyst with tailored porous framework. The ZnCl 2 and NaCl are employed to construct abundant micropores and promote the transformation of partial micropores to mesopores, respectively, reasonably forming a 3D hierarchically porous framework. The catalyst demonstrates a satisfactory surface area (1605 m2/g), promoting mass transport and exposure of FeN 4 sites. Interestingly, the dual melt-salt templates avoid rapid loss of nitrogen during pyrolysis, thus enhancing Fe-N 4 active center density. Therefore, the obtained Fe-N-C material presents outstanding ORR performance in both alkaline and acid media, as well as good stability. The advances of this catalyst are further proved in liquid and solid-state Zn-air battery, with nice discharge stability and high peak power densities. The dual melt-salt-mediated templating strategy is developed to prepare the hierarchically porous Fe-N-C catalyst incorporated with abundant Fe-N x site. [Display omitted] • 3D hierarchically porous structure is engineered using ZnCl 2 and NaCl as templates. • The protective molten salts can sharply increase the Fe-Nx active site density. • The catalyst presents outstanding ORR activity under alkaline/acidic electrolytes. • The catalyst exhibits superior performance in practical Zn-air batteries. [ABSTRACT FROM AUTHOR]

[Display omitted] • According to the theoretical and experimental analysis results, the Cl- can accelerate after complexation with SPS and become the "engine" of copper electroplating. • In this paper, charge density difference, charge transfer and dynamic analysis are used to describe the effect of the SCS and SCCS on the copper surface changes. The acceleration effect of Cl- and bis-(sodium sulfopropyl)-disulfide (SPS) in electroplating solution was analyzed by various electrochemical methods and dynamic simulation with DFT. The cathodic polarization, solution resistance, and nuclear transfer coefficient of the two electroplating systems were analyzed by electrochemical methods; OLYMPUS confocal laser microscope was used to explore the throwing power (TP) and average thickness of the coating (ATCH) in PCB. The multi-step energy change of two systems are used to analyze the reduction process of Cu2+/1+ based on the first principles. The TP and ACTH of SCS (SPS-Cu2+/1+) and SCCS (SPS-Cu2+/1+-Cl-) are 85%, 95%, 56.57 μm and 65.77 μm, respectively. Scanning electron microscope analysis shows that the nucleation rate of the SCCS system is higher than that of the SCS system in 0.2 s. In the dynamic analysis of the system, the reduction of Cu2+/1+ in the SCCS system only needs three steps, while that in the SCS system needs five steps. The experimental and theoretical results show that the reduction rate of Cu2+/1+ in the bath containing Cl- is faster than that in the bath without Cl-. [ABSTRACT FROM AUTHOR]

Rational design and fabrication of high-efficiency electrocatalysts is essential for improving the kinetics of both oxygen evolution reaction (OER) and oxygen reduction reaction (ORR), so as to constructing high-performance rechargeable zinc-air batteries (ZABs). Among the promising candidates, transition metal-based (oxy)hydroxides have attracted extensive attention for their considerable catalytic potential on oxygen-involved reaction, while unsatisfactory intermediate adsorption/desorption strength and low conductivity limit their practical feasibility. In this work, interface engineering modification strategy is proposed, and a metal–organic framework derived heterostructure catalyst of CoFeO x H y -CoP@CC is fabricated. Comprehensively analyses demonstrate that the interaction between phosphide-(oxy)hydroxide induces the interfacial electronic redistribution, while the formed Schottky heterostructure facilitates rapid electron transfer. All these kinetically favorable for both OER and ORR, and leads to remarkable bifunctional performance on CoFeO x H y -CoP@CC, with the OER overpotential of 240 mV to deliver the current density of 10 mA·cm−2, which is better than CoP@CC, CC and RuO 2. In practical applications, liquid zinc-air cells assembled by CoFeO x H y -CoP@CC deliver the peak power density up to 117.55 mW cm−2, which is close to that of 20% Pt/C catalyst (108.48 mW cm−2), and considerable operational performance has also been achieved in all solid-state flexible ZABs. • A metal–organic framework derived phosphide-hydroxide heterostructure of CoFeO x H y -CoP@CC was fabricated. • Heterogenous interaction tunes the electronic configuration and facilitates rapid electron transfer, so that enhances electrocatalytic OER and ORR performance. • CoFeO x H y -CoP@CC employed as cathode in both liquid and solid zinc-air cells show considerable operational performance. [ABSTRACT FROM AUTHOR]

Abstract: Janus Green B (JGB) and Safranine T (ST) were used as levelers in the through-hole (TH) copper electroplating experiments. Although JGB and ST have a similar part in the structure, the results indicate that JGB is an effective leveler used for TH electroplating whereas ST is not. A uniform plating is obtained using 1ppm JGB as a leveler. In contrast, ST could not increase the value of uniformity power (UP). Electrochemical behaviors of JGB and ST were evaluated by potentiodynamic polarization and galvanostatic measurements using rotating disk electrode (RDE). JGB could effectively affect the cathodic polarization. However, the addition of ST changed the cathodic polarization weakly. Quantum chemical calculations based on density functional theory (DFT) were used to obtain some electronic properties and orbital information. The calculations on frontier molecular orbital suggested that the electron donating ability of JGB was higher than that of ST, which gave rise to stronger adsorption of JGB on the cathodic surface and stronger inhibition of copper electrodeposition on the cathode. Furthermore, the results of frontier molecular orbital and Fukui function distributions showed that the Nor aminoazobenzene region of JGB was the probable reactive site for the adsorption of JGB on the copper surface. [Copyright &y& Elsevier]

Abstract: Gel polymer electrolytes containing N-butyl-N-methylpyrrolidinum bis(trifluoromethanesulfonyl) imide (PYR14TFSI) ionic liquid are prepared by the solution casting method. Thermal and electrochemical properties have been determined for these gel polymer electrolytes. The electrical properties are investigated in detail by the linear sweep voltammetry, cyclic voltammetry and impedance spectroscopy with the aid of the equivalent circuit fitting of the impedance spectra. The results show that the studied electrolytes have good self-standing characteristics, and also a sufficient level of thermal stability and a good electrochemical window. The conductivity increases with increasing amount of mixture, and for the studied system, the highest value of the conductivity measured at room temperature is 4.0×10−4 Scm−1. The lithium ions transference number reaches the maximum value when the gel electrolyte contains 33.3wt% PYR14TFSI ionic liquid. Based on the experiments, measurements and fitting, the models describing the lithium ion transmission and the properties of electrolyte/electrode interface are developed. [Copyright &y& Elsevier]

Abstract: Adsorption behaviors of N-butyl-methyl piperidinium bromide (PP14Br) at Cu (001) surface under different electric fields were investigated using molecular dynamics (MD) simulations. We predicted PP14Br could be used as a new leveler for through-hole copper electroplating. In the through-hole electroplating experiments, PP14Br was employed as a leveler. The results of electroplating confirmed the prediction. The electrochemical tests were characterized by potentiodynamic polarization and galvanostatic measurements using rotating disk electrode operated at 100 and 1000rpm. [Copyright &y& Elsevier]

Abstract: The electrodeposition of metallic cobalt from a 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid was investigated. The electrochemical behavior of Co(II) in the ionic liquid on a platinum working electrode at 60°C was studied by cyclic voltammetry and chronoamperometry. The results from the cyclic voltammetry showed that the electrodeposition of metallic Co in the ionic liquid was an irreversible process and controlled by the diffusion of Co(II) on a platinum working electrode. The average value of αn α was calculated to be 0.35 and the diffusion coefficient (D 0) of Co(II) was calculated to be 1.76×10−8 cm2/s at 60°C. Chronoamperometric results indicated that the electrodeposition of Co on a platinum working electrode followed the mechanism of instantaneous nucleation and three-dimensional growth with diffusion-controlled. The cobalt plating was uniform, dense, shining in appearance with good adhesion to the platinum substrate at 60°C. The scanning electron microscope (SEM) micrographs were used to confirm that the cobalt plating was denser and finer at 60°C. Energy dispersive X-ray analysis (EDAX) profile showed that the obtained plating was pure cobalt. X-ray diffraction (XRD) pattern indicated that there was a preferred orientation direction and the average size of cobalt grains was 40nm. [Copyright &y& Elsevier]

Abstract: An environmental-friendly electrolyte of silicate and borate, which contained an addition agent of 1H-benzotriazole (BTA) with low toxicity (LD50 of 965mg/kg), was used to prepare an anodized film on AZ31B magnesium alloy under the constant current density of 1.5A/dm2 at room temperature. Effects of BTA on the properties of the anodized film were studied by scanning electron microscopy (SEM), energy dispersion spectrometry (EDS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), loss weight measurement, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS), respectively. The results demonstrated that anodized growth process, surface morphology, thickness, phase structure and corrosion resistance of the anodized film were strongly dependant on the BTA concentration, which might be attributed to the formation of an BTA adsorption layer on magnesium substrate surface. When the BTA concentration was 5g/L in the electrolyte, a compact and thick anodized film could provide excellent corrosion resistance for AZ31B magnesium alloy. [Copyright &y& Elsevier]

Through-hole cross-section of PCB [Display omitted] • In this paper, charge density difference and charge transfer are used to describe the change process of electroplated PCB. • The structure of PCs and PCCS was optimized for many times, and the reaction process was recorded in detail. Cl− dissolved in electroplating solution is one of the most representative additives. Although the coordination structure of Cl− and polyethylene glycol (PEG) has been investigated, the coordination structure was still highly puzzling. The synergistic effect of PEG and Cl− in electroplating copper is analyzed and discussed by a series of design experiments and DFT. For the experiment, the through-hole of a printed circuit board (PCB) is electroplated with an acid plating solution, and the inhibition ability of complex and nucleation and growth process of Cu are studied by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and chronoamperometry (CA). Theoretical analysis, the adsorption energy and Bader charge are computed by the first principles. Comparing experimental and theoretical results, the copper plating solution with Cl− (PCC) shows better inhibition than that without Cl− (PC), and the average thickness of coating in the hole (ATCH) of PCB are 22.33 μm and 57.76 μm and nucleation and growth process of Cu requires a smaller potential with Cl− in the plating solutions. The energy curve shows that the adsorption energy of PCC* is higher than that of PC*. Due to the coordination of Cl−, the ability of Cu2+/1+ in PCC* to obtain electrons is weakened, thereby suppressing the inability of Cu2+/1+ to be reduced. This work not only illustrates clearly the inhibition ability of Cl− and PEG but also highlights the crucial roles of charge capacity and energy barriers, which can help decipher the electroplating mechanism. [ABSTRACT FROM AUTHOR]

[Display omitted] • GHNCNs_Urea was designed by introducing nitrogen source, increasing pore structures. • The GHNCNs_Urea electrocatalyst exhibited outstanding ORR activity. • The excellent ORR activity was attributed to ultra-high SSA and large pore volume. • The Zn-air battery exhibited a high peak power density and a long-term stability. When designing carbon-based electrocatalysts as Pt-free catalysts for the oxygen reduction reaction (ORR), pore structures is crucial, in addition to creating active sites. Here, N-doped carbon nanosheets were rationally designed by tactfully introducing nitrogen source into the carbonization process, which could increase the density of pore structures and effective active sites. Owing to the ultra-high specific surface area (2127 m2 g−1), large pore volume (5.77 cm3 g−1), and bimodal-pore structure (micropores and mesopores), the optimized catalyst exhibited an excellent ORR activity (a half-wave potential of 0.86 V), as well as outstanding durability and methanol tolerance in alkaline medium. Moreover, it provided excellent stability and high peak power density when used as ORR catalyst in Zn-air battery, exceeding that driven by Pt/C catalyst. This work brings a feasible and universal strategy for fabricating metal-free ORR catalysts. [ABSTRACT FROM AUTHOR]

As a crucial material for fabrication of lithium-ion battery current collector, the properties of electrodeposited copper foil are closely related to the battery performances. How to improve its properties is thus of great importance for battery design and manufacturing. In this paper, we reported a novel composite additive, consisting of collagen, glycerol, hydroxyethyl cellulose, and sodium polydisulfide dipropane sulfonate, for electrodeposition of high-quality copper foil from conventional acid copper sulfate bath. Meanwhile, a pulse superimposed on direct current was used during the preparation process of copper foil. It was demonstrated that the additive could improve the foil's performances, through changing the kinetic parameters of copper electrodeposition in sulfate bath. The optimized bath has a higher allowable current density during superimposed current electrodeposition, in contrast to the situation in direct current electrodeposition. This may then lead to an increase in deposition rate of copper foil, and a further improvement in surface roughness, grain size, residual stress, as well as elongation. Specially, the superimposed current offers a number of adjustable parameters for modulating copper foil's properties in a wide range. [ABSTRACT FROM AUTHOR]

The methanesulfonate system is gradually replacing the traditional highly polluting fluoride electroplating lead （Pb） system with its eco-friendly advantage, and searching for suitable additives is crucially important to obtain uniform Pb coatings in the methanesulfonate system. In this work, a potential additive of thiourea suitable for methanesulfonate-based Pb electroplating was screened based on the theoretical calculations and cyclic voltammetry tests, and the effect of thiourea in the Pb electrodeposition was investigated. Specifically, the adsorption-coordination mechanism was proposed to explain the effect of thiourea by calculating the Bader charge density difference of thiourea on Pb surface and its interaction with Pb2+. Meanwhile, the effects of thiourea on the electrochemical behavior of lead electrodeposition were investigated by cyclic voltammetry and chronoamperometry. The nucleation and growth of Pb follow 3D diffusion-controlled progressive nucleation at the low potential and high thiourea concentration but follow 3D diffusion-controlled instantaneous nucleation at the high overpotential. The appropriate concentration of thiourea could improve the surface morphology of lead coating and make the layer flat and dense. The influence of thiourea on the crystalline orientation and grain size of the coating was analyzed, which indicated that the increase of thiourea concentration favored the formation of the Pb (220) crystal plane and the decrease of grain size. [Display omitted] [ABSTRACT FROM AUTHOR]

Solid-state lithium metal batteries are the one of most promising energy storage devices. To date, however, it is still considered that the interface wetted by liquid electrolytes can enhance the performance of solid-state lithium batteries. In this work, the resistance of the batteries versus their cycle number is investigated using 1 M LiPF 6 EC/DMC (v /v = 1/1) (LE) and 1 M LiTFSI-PP13TFSI (IL) wetting the interface of the LiFePO 4 cathode and the ionic liquid gel polymer electrolyte (ILGPE). The results indicate that, compared with IL-wetting, LE-wetting treatment can more effectively lower the bulk resistance of the battery. The bulk resistance of the batteries does not alter after cycling, indicating that the ionic conductivity is stable during the charging/discharging. The interfacial resistance and charge transfer resistance of LE-wetted batteries increase by 50 times and 825 times after 50 cycles at C/3 and 23 °C, while the resistance of IL-wetted batteries increase by less than 20 times. Furthermore, the formation of the electrode electrolytes interphase during cycling, which probably accounts for the change of battery resistance observed in solid-state lithium batteries. The ILGPE had superior compatibility and stability with LiFePO 4 cathode, which is also the most basic guarantee for the battery's stable cycling. Unlabelled Image • Battery performance and rate capability with interface wetting are studied. • The impedance of the batteries versus their cycling number is tested. • The interfacial chemistry of the batteries after a full discharge is investigated. • Organic liquid electrolytes is easy to decompose and shorten battery life. [ABSTRACT FROM AUTHOR]

With the scarcity of fuel energy, non-noble metal compounds assisted water of electrolysis is becoming a potential candidate for cost-effective and high-quality hydrogen production. To date, transition metal phosphide (TMP) has been considered as one of the most promising catalysts for water splitting because of its multitudinous but controlled constituent elements and stoichiometric ratios. In this review, the electronic structure analysis of TMP dialectically reveals the active derivation for catalyzing hydrogen evolution (HER) and oxygen evolution reaction (OER). And then the strategies of rationally designing the structure and composition of electrocatalyst to improve its intrinsic activity are discussed, especially interface engineering. Besides, this review also focuses on the negligible stability issue during the water splitting process. In the end, some key challenges and research orientations of TMPs are pointed out, which is instructive for developing high-efficient and stable electrocatalysts for water splitting. • The activity derivation of transition metal phosphide (TMP) for water splitting. • Optimization strategies for TMPs to modulate their electron structure. • Strategies to improve conductivity and durability for the first time. • Prospects for the development of the design and synthesis of TMP in water splitting. [ABSTRACT FROM AUTHOR]

In order to replace the highly poisonous cyanide zincate process of Al alloy, an eco-friendly approach was developed, i.e., electrodeposition of Cu-Zn coating from ionic liquid/ethanol mixed bath. It was demonstrated that the Cu 5 Zn 8 alloy produced from 1-ethyl-3-methylimidazolium trifluoromethylsulfonate (EMImTfO) and 20% (Volume percent) ethanol mixtures under optimal conditions showed cauliflower-shaped structure with a (330) preferred orientation, which could significantly improve the corrosion resistance of Al substrate in Watts bath, thereby elevating Ni coating quality. The overall property of Cu-Zn intermediate layer and its subsequent coating, including compactness, adhesive strength and corrosion resistance is approximately the same as that of cyanide zincate layer and its surface coating, suggesting that the new method is an ideal alternative to conventional zincate treatment. • Cu-Zn coating is electrodeposited from EMImTfO ionic liquid/ethanol mixtures. • Its overall property is approximately the same as that of cyanide zincate layer. • A high-quality Ni coating can be obtained on Cu-Zn coating from Watts bath. • It also has similar property to the Ni coating deposited on cyanide zincate layer. • This method has the great potential to replace cyanide zincate process of Al alloy. [ABSTRACT FROM AUTHOR]

Silicon is a promising anodic material used in lithium-ion battery (LIB) to improve the specific energy. While the huge volume change during lithiation/delithiation and low intrinsic conductivity has been a bottle neck of silicon anode. For this sake, carbon shell was used to enhance the conductivity, and hollow structure to buffer the volume swelling/shrinking during cycles. In this work, we synthesized a hollow yolk-shell structure Si/SiC/C (SSC) anode by one-step magnesiothermic reductive reaction. At first, polydopamine (PODA) was used as carbon source to optimize the dosage of magnesium powder and reaction temperature. Then resorcinol formaldehyde (RF) resin was used as another carbon source to prepare several samples with different carbon shell thicknesses. A vital parameter, critical thickness, about 10nm of final shell was proposed to keep the hollow yolk-shell morphology. During this one-step exothermic reaction, Si and C spontaneously reacted and formed inter SiC layer with high modulus. The half-cell with SSC anode delivered a capacity of 505.8 mA h g-1 after 220 cycles at a current density of 100 mA g-1. This novel method is facile to realize and might be used in other fields like composite plating and material modification etc. [ABSTRACT FROM AUTHOR]

The electrochemical characterization of new electrode materials in the lithium battery field is commonly conducted using a simplified two-electrode configuration, known as the "half-cell" concept. However, this approach often overlooks the critical error related to the polarizability of the lithium electrode, especially when the working electrode has a high areal capacity and the half-cell undergoes long-term cycling. In our work, we propose a simple way to improve the properties of the Li electrode, which is using a superstoichiometric Li 1+x Al surface enrichment of the metallic lithium foil in situ by direct contact with aluminum foil, serving as a counter/reference electrode. The method eliminates the inhomogeneity of the lithium surface and creates a buffer zone between the highly active lithium electrode and liquid organic electrolytes. The high lithium content in the surface alloy allows the electrode to behave like a lithium electrode while providing low polarization and maintaining a stable potential throughout the long duration of cycling. By implementing this method, we improve the charge/discharge characteristics of high-capacity electrodes and obtain more accurate evaluations of their electrochemical performance. [Display omitted] • A new counter/reference electrode——Li@Li 1+x Al electrode. • The Li@Li 1+x Al electrode exhibits an equilibrium potential of Li one. • The Li@Li 1+x Al electrode is more stable than Li electrode in coin-type half-cell. [ABSTRACT FROM AUTHOR]

[Display omitted] • Suppressing effect of NBT on cobalt electrodeposition is confirmed by electrochemical analysis and in situ Raman spectra. • Accelerating effect of NBT on HER is studied by electrochemical methods and finite element simulation. • Suppressing-accelerating effect of NBT is proposed to illustrate the influence of NBT during cobalt electrodeposition. • Nitrotetrazolium blue chloride and convection is of grain refinement during cobalt electrodeposition. Achieving cobalt superconformal (bottom-up) growth is significantly important. Electrochemical methods, including cyclic voltammetry, electrochemical impedance spectra and EQCM-derived Coulomb-voltage curves, were used to confirm the suppressing influence of new suppressor Nitrotetrazolium Blue chloride (NBT). In situ Raman spectroscopy was used confirm that NBT can effectively adsorb on cobalt surface. Besides, EQCM-derived Coulomb-voltage illustrates that it is more beneficial for cobalt electrodeposition at high pH. The NBT effect on hydrogen evolution reaction (HER) was studied by LSV and chronoamperometry. Finite element simulation is used to investigate the accelerating effect of NBT on HER and convection. Suppressing-accelerating effect is proposed to illustrate effect of NBT. NBT can not only suppress the cobalt deposition but also can accelerate local convection by intensifying HER, which can in turn strengthen NBT adsorption. SEM analysis demonstrates that convection and NBT can refine grain. High-quality cobalt is achieved with low SDT values ranging from 24 μm to 45 μm and high FP values (75.4 % for 150 μm, 88.9 % for 100 μm and 87.2 % for 50 μm). [ABSTRACT FROM AUTHOR]

Abstract Redox polymers bearing stable nitroxyl radical groups, such as poly-TEMPO-methacrylate (PTMA), are attractive candidates for application in power sources of novel kind, which combine the high power output of supercapacitors and high energy of rechargeable batteries. An important advantage of PTMA is the availability and low cost of the starting materials combined with high charging/discharging voltage, fast electron transfer kinetics and good mechanical properties of the polymer. However, low electron conductivity and high solubility in common organic electrolytes hamper the broad application of TEMPO-based compounds as cathode materials. In the present work, we report a simple strategy to overcome these limitations by the use of a practical and polymer-rich electrode based on redox-conducting polymer blends of polymerized nickel complexes with salen-type Schiff bases and PTMA. Electrochemical properties of the material are tested both in thin film systems and in asymmetric supercapacitor prototypes with aqueous electrolyte, which demonstrate high specific capacity (83 mAh g−1 at 1C, 53 mAh g−1 at 5C and 47 mAh g−1 at 10C), high rate capability as well as cycling stability (55% capacity retention after 1000 cycles). Graphical abstract Image 1 Highlights • Novel TEMPO- and Ni-salen polymer composite cathode material is reported. • Synergistic interaction of the components secures good durability and capacity. • TEMPO-based redox polymer increases the specific capacity and stability in water. • Ni-salen allows to overcome the low conductivity typical for redox polymers. [ABSTRACT FROM AUTHOR]

Nitrogen-doped graphene (N-G) is considered as a promising catalyst for the oxygen reduction reaction (ORR). However, the contributions of pyridinic N, pyrrolic N and graphitic N in N-G for the ORR catalytic activity are controversial. In this work, the contents of pyridinic N, pyrrolic N and graphitic N in N-G were transformed by annealing at different temperatures. It is found that the total N content in N-G is not the critical factor to determine the ORR activity. An increase in the annealing temperature can enhance the content of graphitic N in N-G, causing an improved catalytic ORR activity, which confirms that graphitic N is the active component. Moreover, the enriched graphitic N in the N-G-1000 catalyst shows a half-wave potential (E1/2) of 0.862 V, 29 mV higher than that of the commercial Pt/C catalyst (0.833 V), which is one of the best reported for ORR metal-free catalysts. [ABSTRACT FROM AUTHOR]

Abstract Ionically conductive polymer electrolytes represent a class of safe and environment-friendly electrolytes for next-generation alkali metal batteries. Understanding the interplay between composition-driven interfacial processes and battery performance can fundamentally inform the design of polymer electrolytes for practical applications. In this study, we fabricate lithium metal batteries based on transparent free-standing ionic liquid gel polymer electrolytes (ILGPEs) and LiFePO 4 cathodes. We develop the ILGPEs using a composite of poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), N-methyl-N-propylpiperidinium bis(trifluoromethanesulfonyl)imide (PP13TFSI), and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI). A thorough compositional optimization shows that the lithium ion conductivity of the ILGPE increases with the increase of PP13TFSI and LiTFSI, reaching maxima of 1.3 mS cm−1 at 23 °C and 5.82 mS cm−1 at 80 °C when the ILGPE contains 60 wt% PP13TFSI and 20 wt% LiTFSI. The optimized ILGPE exhibits excellent interfacial stability against the lithium metal, as signified by the stable interfacial resistance upon long-term storage. The LiFePO 4 |ILGPE|Li cells can deliver superior battery performance with a practical capacity approaching 89.5% of the theoretical capacity and capacity retention of 95.0% after 200 cycles. The formation of the electrode–electrolyte interphases takes place primarily during the initial cycles, which likely accounts for the activation period observed in LiFePO 4 |ILGPE|Li cells. Graphical abstract Image 1 Highlights • Ionic liquid gel polymer electrolytes with high ionic conductivity were prepared. • The compatibility of ILGPE-Li metal was studied under practical conditions. • Solid-state LFP cells showed remarkable discharge capacity and cycle life at RT. • The interfacial chemistry of cells was investigated as a function of cycle number. [ABSTRACT FROM AUTHOR]

A hexagonal prism CuSn alloy was prepared at room temperature from 1-ethyl-3-methylimidazolium dicyanamide ([Emim][DCA]) by the direct template-free electrodeposition method with different concentrations of Cu(I) and Sn(II) at a low current density of 0.04 A dm−2. Moreover, the electrodeposition time was also investigated, and the results indicated that the composition of the CuSn alloy became complex and the structure turned unstable with expanding time. The cycling performance of the hexagonal prism-structural CuSn electrode was investigated, with the first discharge capacity of 345 mAh g−1 and a discharge capacity of about 210 mAh g−1 after 10 cycles. [ABSTRACT FROM AUTHOR]

Ni/diamond dicing blades is the main tool for scribe of silicon wafer at present. In order to decrease the width of dicing slot on the wafer, it is necessary to reduce the thickness of blades, and to increase the hardness, toughness and wear resistance of the Ni/diamond composite coatings in the process of electrodeposition. In this paper, 1,4-bis(2-hydroxyethoxy)-2-butyne (BEO) was used as an organic additive in the composite baths containing nickel amino-sulfonate, nickel chloride, boric acid, sodium dodecyl sulfate (SDS) and diamond particles in sizes of 3–5 µm, in order to improve the properties of Ni/diamond coatings and produce ultra-thin Ni/diamond dicing blades. The textures of Ni/diamond composite coatings were mainly Ni (200) and Diamond (111) since the addition of BEO in the baths inhibited the growth of Ni (111) and Ni (220). Quantum chemical calculations and molecular dynamics (MD) simulations showed that BEO could adsorb at the nickel surface strongly and inhibit the electrodeposition of nickel atoms. With the increase in concentration of BEO in the baths, the cathodic polarization potentials shifted to more negative direction and the thicknesses of the coatings decreased. Adding the appropriate amount of BEO (0.1–0.2 g/L) in the baths, the roughness of the coating decreased the number of individual diamond particles in the coating increased, and the hardness and the wear resistance of the coating was improved. When the thickness of Ni/diamond composite coating on aluminum alloy wheeled substrate was 15 µm, the width of its dicing slot was 22 µm. However, the addition of BEO in the bath cannot change the adhesive wear mechanism of the coating. [ABSTRACT FROM AUTHOR]

Developing transitional metal-based electrocatalysts with outstanding oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) performance is essential for energy-efficiency alkaline water electrolysis. Herein, a group of heterostructured electrocatalysts constructing of nickel-based hydroxide (NiX(OH) x , X = Co, Fe) nanosheets decorated on copper phosphide nanowires arrays，were fabricated. Both of the as-prepared NiCo(OH) x -CuP/CF and NiFe(OH) x -CuP/CF present outstanding HER and OER activity, with the overpotential of 79 and 202 mV to deliver 10 mA cm−2, respectively, along with considerable long-term stability. Encouragingly, the NiCo(OH) x -CuP/CF ǀǀ NiFe(OH) x -CuP/CF couple enables sustainable alkaline water electrolysis and powered by a solar-powered system. In-depth analyses elucidate that owing to the modulated heterogeneous interfacial states, both of the catalytic kinetics can be optimized targeting HER and OER, respectively. More significantly, a regulated electrode-electrolyte microenvironment induced by unique arrays nanostructure efficiently promote the electron-mass transfer capacity, thereby facilitating the catalytic activity expression. This work demonstrates the desirable catalytic performance by rationally designing of hydroxide-phosphide heterostructure, and highlights the structural features on catalytic performance promotion. • A delicate NiCo(OH) x -CuP/CF and NiFe(OH) x -CuP/CF catalysts were fabricated, in which the heterogeneous interfacial synergy effect between copper phosphide and nickel-based hydroxide enables the catalytic performance breakthrough. • The modulation of current distribution for the HER and OER optimizing the reaction kinetics, is achieved by interfacial synergy effect between Cu 3 P and nickel-based hydroxide. • The arrays nanostructure features high active area, good electrical conductivity, while also regulate the interfacial microenvironment between electrocatalysts and electrolyte that facilitates electro-mass transfer. [ABSTRACT FROM AUTHOR]