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Acting as a passive protective layer, solid‐electrolyte interphase (SEI) plays a crucial role in maintaining the stability of the Li‐metal anode. Derived from the reductive decomposition of electrolytes (e.g. anion and solvent), the SEI construction presents as an interfacial process accompanied by the dynamic de‐solvation process during Li‐metal plating. However, typical electrolyte engineering and related SEI modification strategies always ignore the dynamic evolution of electrolyte configuration at the Li/electrolyte interface, which essentially determines the SEI architecture. Herein, by employing advanced electrochemical in situ FT‐IR and MRI technologies, we directly visualize the dynamic variations of solvation environments involving Li+‐solvent/anion. Remarkably, a weakened Li+‐solvent interaction and anion‐lean interfacial electrolyte configuration have been synchronously revealed, which is difficult for the fabrication of anion‐derived SEI layer. Moreover, as a simple electrochemical regulation strategy, pulse protocol was introduced to effectively restore the interfacial anion concentration, resulting in an enhanced LiF‐rich SEI layer and improved Li‐metal plating/stripping reversibility. [ABSTRACT FROM AUTHOR]

Acting as a passive protective layer, solid‐electrolyte interphase (SEI) plays a crucial role in maintaining the stability of the Li‐metal anode. Derived from the reductive decomposition of electrolytes (e.g. anion and solvent), the SEI construction presents as an interfacial process accompanied by the dynamic de‐solvation process during Li‐metal plating. However, typical electrolyte engineering and related SEI modification strategies always ignore the dynamic evolution of electrolyte configuration at the Li/electrolyte interface, which essentially determines the SEI architecture. Herein, by employing advanced electrochemical in situ FT‐IR and MRI technologies, we directly visualize the dynamic variations of solvation environments involving Li+‐solvent/anion. Remarkably, a weakened Li+‐solvent interaction and anion‐lean interfacial electrolyte configuration have been synchronously revealed, which is difficult for the fabrication of anion‐derived SEI layer. Moreover, as a simple electrochemical regulation strategy, pulse protocol was introduced to effectively restore the interfacial anion concentration, resulting in an enhanced LiF‐rich SEI layer and improved Li‐metal plating/stripping reversibility. [ABSTRACT FROM AUTHOR]

SiO x is proposed as one of the most promising high-performance anodes for its favorable capacity and stable lithium insertion/extraction electric potential, however its effective commercial application still faces giant challenge. To overcome poor electrical conductivity and huge volume effect of silicon oxide-based material, we adopt a valid strategy to synthesis the SiO x nanosphere double-wrapped by MoS 2 and multi-walled carbon nanotubes (CNTs) as anode material. The influences of MoS 2 and CNTs on the structure, morphology and electrochemical performances of nanohybrid are probed detailly by transmission electron microscopy, X-ray photoelectron spectroscopy and charge-discharge measurements. The results show that as-prepared nanohybrids release a steady reversible capacity of 798 mAh g−1 with high capacity retention of 81.4% at 500 mA g−1 after 300 cycles. The outstanding electrochemical properties can be ascribed to the facts that the hollow mesoporous structure affords ample buffer space and the introduction of MoS 2 with a two-dimensional layered structure can provide more exposed active-sites for lithium adsorption, as well as the CNTs wrapping can form a favorable conductivity matrix, endowing the nanocomposites with great structural stability. Accordingly, this new structure design by means of a heterogeneous dual-wrapped architecture develops a significant strategy for the development of high-performance SiO x -based anode materials. Unlabelled Image • Heterogeneous dual-wrapped architecture of SiO x /MoS 2 -CNTs is successfully prepared. • The hollow structure shortens the transportation of Li+/e− and offers buffer space. • Wrapping MoS 2 can own more exposed active sites for promoting transport of Li+/e−. • The conductive twining CNTs form a favorable conductivity framework. • The material presents excellent cycling performance and rate capability. [ABSTRACT FROM AUTHOR]

Abstract Dendritic Li deposition on graphite anodes of Li-ion batteries (LIBs) not only deteriorates the anode performance but also causes safety concerns. We demonstrate here a proof-of-concept graphite anode containing a polymer coating that effectively mitigates Li dendrite formation under harsh lithiation conditions. It is shown that Li dendrites with dimensions ranging from a few tens nanometers to microns occur readily on granular graphite electrodes either under 20% over-lithiation at 0.2C or fast lithiation up to 10C rate. In contrast, the graphite anode with a conformal thin coating of high-polarity β-phase polyvinylidene difluoride (PVDF) on graphite particles exhibits dendrite-free Li plating under either condition. Moreover, the PVDF coated graphite anode exhibits substantially improved cycling stability with high Coulombic efficiencies under the Li-plating conditions. The rise of charge-transfer resistance due to over-lithiation is reduced. The proof of concept for adopting a dendrite-suppressing polymer coating on graphite anodes offers a new strategy for improving battery safety and renders more options for cell design in enhancing energy and power performances for the state-of-the-art LIBs. Graphical abstract Image 1 Highlights • Graphite anode with lithium dendrite suppression polymer coating is demonstrated. • Li dendrites occur readily on graphite anode under over-lithiation and fast charge. • β-phase PVDF coating effectively suppresses Li dendrite formation on graphite. • β-phase PVDF coating reduces charge-transfer resistance rise upon over-lithiation. [ABSTRACT FROM AUTHOR]

Abstract: In this study, the coking resistance of anode supported direct ethanol solid oxide fuel cell with a Ni–S x anode was investigated comparatively with the conventional cell using pure Ni catalyst. The surface catalytic properties of Ni were manipulated via depositing a layer of S atoms. It was confirmed that on the surface of Ni, a combination of S monolayer and elemental S was formed without producing Ni3S2 phase. The developed Ni–S x cell exhibited a significantly improved coke resistivity in ethanol feed while maintaining an adequately high performance. The S species on Ni enabled the suppression of the coke formation as well as the alleviation of the metal dusting effect of the anode structure. After operating in ethanol fuel for identical period of time at 850 °C, a maximum power density of 400 mW cm−2 was sustained whereas the conventional cell performance decreased to less than 40 mW cm−2 from the original 704 mW cm−2. In an optimized stability test, the Ni–S x cell operated at 750 °C for more than 22 h until the fuel drained without any degradation. [Copyright &y& Elsevier]

Owing to zinc dendrites and parasitic reactions, aqueous Zn‐metal batteries often suffer from poor reversibility and cyclability. Electrolyte additives present a promising strategy to improve Zn anode stability. However, the ever‐evolving perspectives and mechanisms, paradoxically, complicate battery design, causing a scenario where any electrolyte additive seems to be effective. Herein, it is taken ionic liquid (IL) additives as an example and detailed explored the impact of three typical IL anions, namely OTF−, TFA−, and BF4−. It is identified that the primary determinant of electrolyte additives as their electrical double layer (EDL) structures and their subsequent solid‐electrolyte interface (SEI) composition. An advantageous EDL structure, akin to an ion‐shield, can reduce the absorption of H2O molecules, which further enrich the SEI with zincophilic and hydrophobic components, thereby mitigating parasitic reactions and Zn dendrite formation. As a result, the Zn||Zn cell with optimal [EMIM]OTF additives demonstrates an exceptional cycling life under challenging conditions, its cumulative plated capacity surpasses most previously reported results by utilizing different IL additives. This work extends beyond performance enhancements, representing a valuable exploration of key criteria for electrolyte additives is believed. These insights are expected to offer fundamental guidance for future research and electrolyte design. [ABSTRACT FROM AUTHOR]

Abstract: The performance of La0.4Sr0.6TiO3±δ -Y0.2Ce0.8O2−δ (LST-YDC) composite anodes in solid oxide fuel cells significantly improved when 0.5% H2S was present in syngas (40% H2, 60% CO) or hydrogen. However, electrochemical impedance spectroscopy measurements at OCV showed that polarization resistance of the cell increased when the concentration of H2S exceeded 0.5%. Gas chromatographic and mass spectrometric analyses revealed that the rate of electrochemical oxidation of all fuel components improved when H2S was present in the fuel. Electrochemical stability tests performed under potentiostatic conditions showed that there was no power degradation caused by the presence of H2S in different feeds, and that there was power enhancement when 0.5% H2S was present. [Copyright &y& Elsevier]

Abstract: Hydrogen sulfide, usually considered to be an anode catalyst poison, strongly promotes methane oxidation over sulfur resistant catalysts. The role of H2S in oxidation of sour CH4 feed over a sulfur resistant SOFC anode catalyst at 850°C has been determined through thermodynamic and experimental studies. The anode material was an intimately mixed 50/50 mass ratio composite of La0.4Sr0.6TiO3−δ and YSZ. The power density improved dramatically from 2mWcm−2 with pure CH4 as fuel to more than 450mWcm−2 for CH4 containing 20% H2S. However, H2S was not the only fuel converted, and its interaction with CH4 was the key factor in enhancement of performance. The anode effluent gas mixture included H2S, SO2, H2 and CS2 consistent with thermodynamic predictions. The role of H2S in the CH4 oxidation mechanism was determined, and showed that CH4 and H2S must be considered together as a fuel and not as two separate fuels. The types of electrochemical reactions that occurred in the fuel cell were strongly dependent on potential. [Copyright &y& Elsevier]

Abstract: The level of barium doping in lanthanum strontium titanate (La0.4Sr0.6−x Ba x TiO3, 0≤ x ≤0.2; LST, x =0; LSBT, x >0), prepared by solid state synthesis, affects its performance as anode in solid oxide fuel cells (SOFCs). Cell structures of LST and all LSBT were similar. The oxidation state of Ti in all compounds was reduced by a comparable amount when LST or LSBT was heated under reducing conditions to form La0.4Sr0.6−x Ba x Ti0.59 4+Ti0.41 3+O2.97. All fuel cells using LST or LSBT had high activity for conversion of hydrogen or methane, and the activity increased with the level of substitution by Ba. In addition, performance was enhanced when H2S was present in either CH4 or H2 fuel. There was good contact between YSZ electrolyte and each LSBT or LSB anode. [Copyright &y& Elsevier]

Abstract: Whereas Ce0.9Sr0.1Cr0.5V0.5O3 is an active fuel cell anode catalyst for conversion of only the H2S content of 0.5% H2S–CH4 at 850°C, inclusion of 5wt% NiO to form a composite catalyst enabled concurrent electrochemical conversion of CH4. A fuel cell with a 0.3mm thick YSZ membrane and Ce0.9Sr0.1Cr0.5V0.5O3 as anode catalyst had a maximum power density of 85mWcm−2 in 0.5% H2S–CH4 at 850°C, arising only from the electro-oxidation of H2S. Using a same thick membrane, promotion of the anode with 5wt% NiO increased the total anode electro-oxidation activity to afford maximum power density of 100mWcm−2 in 0.5% H2S–CH4. The same membrane provided 30mWcm−2 in pure CH4, showing that the incremental improvement arose substantially from CH4 conversion. Performance of each anode was stable for over 12h at maximum power output. XPS and XRD analyses showed that an increase in conductivity of Ce0.9Sr0.1Cr0.5V0.5O3 in H2S-containing environments resulted from a change in composition and structure from the tetragonal oxide to monoclinic Ce0.9Sr0.1Cr0.5V0.5(O,S)3. [Copyright &y& Elsevier]

Abstract: The stability and activity in 0.5% H2S–CH4 of Ce0.9Sr0.1VO3 and Ce0.9Sr0.1VO4 anode materials for H2S-containing CH4 fueled SOFCs have been determined. XRD showed that Ce0.9Sr0.1VO4 was reduced when the fuel gas was 0.5% H2S–CH4, while Ce0.9Sr0.1VO3 remained stable over 24h at 950°C. Electrochemical tests in 0.5% H2S–CH4 showed stable performance at 950 and 800°C for cells comprising Ce0.9Sr0.1VO3|YSZ|Pt. Comparison of fuel cell performances using 0.5% H2S–CH4, 0.5% H2S–N2 and 5% H2S–N2 as feeds showed that Ce0.9Sr0.1VO3 was not active for oxidation of methane, but highly active for conversion of H2S. Electrochemical impedance results were consistent with the finding that the anode was activated only in an environment that contained H2S. Conductivity measurements showed there was an increase in conductivity in H2S-containing environments, and that this increase resulted from a change in composition and structure from the oxide to monoclinic Ce0.9Sr0.1V(O,S)3, as evidenced by XPS and XRD analyses. [Copyright &y& Elsevier]

Abstract: Au/MoS2 is a promising anode catalyst for conversion of all components of H2S-containing syngas in solid oxide fuel cell (SOFC). MoS2-supported nano-Au particles have catalytic activity for conversion of CO when syngas is used as fuel in SOFC systems, thus preventing poisoning of MoS2 active sites by CO. In contrast to use of MoS2 as anode catalyst, performance of Au/MoS2 anode catalyst improves when CO is present in the feed. Current density over 600mAcm−2 and maximum power density over 70mWcm−2 were obtained at 900°C, showing that Au/MoS2 could be potentially used as sulfur-tolerant catalyst in fuel cell applications. [Copyright &y& Elsevier]

SiO x has aroused great attractions as a promising substitute for the anode materials of high-performance lithium-ion batteries (LIBs) because of the high specific capacity and the longer cycle life as well as relatively low volume expansion compared to Si. However, the unstable structure and poor conductivity of the SiO x lead to unideal electrochemical properties in LIBs, and thus hindering the widespread application of the SiO x anode. Herein, a facile approach has been put forward to prepare the high-performance mesoporous structure SiO x /carbon (m-SiO x /C) composites by electrospinning technique and sintering processes. The spherical SiO x nanoparticles are well anchored on the carbon fibers, and the reserved space can accommodate large volume expansion of the SiO x materials. Besides, the fibrous carbon materials can significantly enhance the conductivity for the SiO x anodes. Therefore, the resultant m-SiO x /C composites exhibit high discharge specific capacity of 1434 mAh g−1 at 500 mA g−1 with 67.5% capacity retention after 500 cycles and the good rate properties of 410 mAh g−1 at 2000 mA g−1. In consequence, the reasonable structural design and innovative fabrication technique can facilitate the practical application for the m-SiO x /C composites and further promote the comprehensive electrochemical performance of LIBs. [ABSTRACT FROM AUTHOR]

Oriented construction of high-performance mesoporous TiNb 2 O 7 (m-TNO) is important to the design innovation of anode material for next-generation lithium-ion batteries (LIBs) due to the high capacity and long cyclic life of m-TNO. However, the conductivity enhancement of m-TNO and thus accelerating Li+ transfer is still the key point to realize its practical application in LIBs. In this work, a synergistic strategy based on the single-core/dual-shell m-TNO@TiC@NC hierarchical structure is put forward, which is achieved by using m-TNO as host architecture as well as TiC and N-doped carbon layer (NC) as dual-shell layers. The results show that the m-TNO@TiC@NC hierarchical structure can not only provide an integrated conductive network to improve the conductivity of m-TNO, but also can establish a reinforced structure to maintain the anode stability. Besides, it is found that the m-TNO@TiC@NC composite has a high capacity of 328.6 mAh g−1 at 0.5 C after 200 cycles and a high-rate capacity of 186.4 mAh g−1 at 5 C by galvanostatic discharge-charge tests. Therefore, this kind of special single-core/dual-shell structure design can convincingly enhance the conductivity of m-TNO and facilitate the Li+ transfer rate, thus promoting electrochemical performances of LIBs due to the synergistic effect of dual-shell layers. Image 1 • The m-TNO@TiC@NC composite is achieved by using m-TNO as host architecture as well as TiC and NC as dual-shell layers. • The m-TNO@TiC@NC composite shows the single-core/dual-shell hierarchical structure. • The new-type ceramic material TiC is used as conducting layer. • The m-TNO@TiC@NC composite displays good electrochemical performance. [ABSTRACT FROM AUTHOR]

The activated carbon cloth (ACC@TNO) with flexible self-support structure, which is decorated by TiNb 2 O 7 (TNO) nanoparticle, is successfully obtained through hydrothermal reaction and calcination process in high temperature, and is used as the binder-free anode material of lithium ion batteries (LIBs). The morphology characteristic, pore structure properties and the phase structure of the ACC@TNO composites are detailedly studied by the scanning electron microscopy (SEM), Brunauer–Emmett–Teller adsorption/desorption measurement (BET) and X-ray diffraction (XRD). Meanwhile, the electrochemical properties of ACC@TNO composite are further tested by cyclic voltammetry and galvanostatic charge-discharge tests. As a result, the LIBs with ACC@TNO as anode material shows an initial discharge capacity of 356 mAh g−1 and an initial coulombic efficiency (ICE) of 87% at the current density of 0.5 C with the voltage window of 1.0–3.0 V. It also has been found that the reversible capacity can still keep as 290 mAh g−1 with the capacity retention of 81% after 500 cycles. Besides, when the cutoff voltage range is set to 0.01–3.0 V, the reversible capacity can reach 340 mAh g−1. Apparently, this work is of great significance for the exploration of the new anode materials with high performance and long cyclic life in next-generation LIBs. Image 1 • The ACC@TNO composite is obtained by epitaxially growing TNO particles on ACC surface like stab grown on the thorn. • The thiourea is use as a nitrogen source and sulfur source to treat the carbon cloth. • The ACC@TNO composite is binder-free anode material. • The ACC@TNO composite displays good electrochemical performance. [ABSTRACT FROM AUTHOR]

Abstract The hollow mesoporous silicon nanobox dually encapsulated by tin oxide and carbon layers is successfully fabricated and used for anode active material of lithium ion battery. The effects of the double coating layers on the structure, morphology and features of nanocomposite are systematically investigated by transmission electron microscopy, field emission scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and galvanostatic charge-discharge tests. The results reveal that hollow mesoporous silicon/tin oxide/carbon nanobox has the adjustable void space and a rationally designed hierarchical structure, which permits the free expansion of Si core without breaking double coating layers and preserves the structural integrity of the electrode during the (de)lithiation processes, as well as significantly enhances the electronic conductivity of anode. As expected, the resultant hollow mesoporous silicon/tin oxide/carbon nanobox exhibits a high reversible capacity up to 1535 mAh g−1 at 0.5 A g−1 after 200 cycles of (dis)charging due to the unique nanostructure. Especially, the as-synthesized nanocomposite exhibits an excellent rate capacity as high as 858 mAh g−1 at 6 A g−1. This rational structure design and innovative approach can be of visible significance for the development of new anode active materials of next-generation lithium-ion battery. Graphical abstract Image 1 [ABSTRACT FROM AUTHOR]

Protonic ceramic ethane fuel cells fed by hydrocarbon fuels are demonstrated to be effective energy conversion devices. However, their practical application is impeded by a lack of anode materials combining excellent catalytic activity with good chemical stability and anti‐carbon deposition properties. In this work, in which Sr2Fe1.5Mo0.5O6‐δ (SFM) double perovskite oxide is used as the matrix framework, catalytic activity toward H2 and C2H6 oxidation is systematically investigated using Ba‐doping. It is found that the concentration of the oxygen vacancy is gradually improved with increased Ba content to significantly enhance catalytic activity toward H2 and C2H6 oxidation. From the series studied, Ba0.6Sr1.4Fe1.5Mo0.5O6‐δ exhibits the highest catalytic activity, while the power densities of the electrolyte‐supported Ba0.6SFM/BaCe0.7Zr0.1Y0.2O3‐δ (BCZY)/La0.58Sr0.4Co0.2Fe0.8O3‐δ (LSCF)‐Sm0.2Ce0.8O2‐δ (SDC) single cell reach 205 and 138 mW cm–2 at 750°C in H2 and C2H6, respectively. The ethane conversion rate of the experimental cell is shown to reach 38.4%, while simultaneously maintaining ethylene selectivity at 95%. Furthermore, the single cell exhibits no significant attenuation during stable operation for 20 h, as well as demonstrating excellent anti‐coking performance. The proposed results suggest that Ba0.6Sr1.4Fe1.5Mo0.5O6‐δ represents a promising anode material for efficient hydrocarbon‐related electrochemical conversion to realize the coproduction of ethylene and power in protonic ceramic ethane fuel cells. [ABSTRACT FROM AUTHOR]

A La 0.5 Sr 0.5 Fe 0.9 Mo 0.1 O 3-δ -CeO 2 (LSFM-CeO 2) composite was prepared by impregnating CeO 2 into porous La 0.5 Sr 0.5 Fe 0.9 Mo 0.1 O 3-δ perovskite and was used as an anode material for proton-conducting solid oxide fuel cells (SOFCs). The maximum power densities of the BaZr 0.1 Ce 0.7 Y 0.2 O 3-δ (BZCY) electrolyte-supported single cell with LSFM-CeO 2 as the anode reached 291 mW cm−2 and 190 mW cm−2 in hydrogen and ethane fuel at 750 °C, respectively, which are significantly higher than those of a single cell with only LSFM as the anode. Additionally, the ethylene selectivity and ethylene yield from ethane for the fuel cell at 750 °C were as high as 93.4% and 37.1%, respectively. The single cell also showed negligible degradation in performance and no carbon deposition during continuous operation for 22 h under an ethane fuel atmosphere. The improved electrochemical performance due to the impregnation of CeO 2 can be a result of enhanced electronic and ionic conductivity, abundant active sites, and a broad three-phase interface in the resultant composite anode. The LSFM-CeO 2 composite is believed to be a promising anode material for proton-conducting SOFCs for co-producing electricity and high-value chemicals from hydrocarbon fuels. [ABSTRACT FROM AUTHOR]

Abstract: The system LSBT/YSZ (LSBT is La0.4Sr0.5Ba0.1TiO3) is a promising combination as an anode material for full ceramic SOFCs. An anode comprising a porous layer of YSZ impregnated with LSBT shows good performance for conversion of high sulfur content fuels. The microstructures within the composite matrix were determined and correlated with the parameters of the production process. The anodes were characterized electrochemically using impedance spectroscopy (EIS) and potentiodynamic tests performed at 850 °C with various fuels to determine the effect of H2S in the feeds: H2, H2/H2S (5000 ppm), CH4, CH4/H2S (5000 ppm). The highest power densities (200 mW cm−2 in H2/H2S) were obtained for LSBT/YSZ composites after impregnation six times with LSBT, corresponding to 12.6 wt% LSBT; further impregnations dramatically decreased performance as a result of restricted access of fuel to active sites. [Copyright &y& Elsevier]

Abstract: Undoped BaTiO3 perovskite oxide is more effective than SrTiO3 and La2Ti2O7 oxide as anode catalyst in SOFC fueled with H2S-containing methane. Electrochemical performance, impedance spectroscopy and other characterizations show that pure BaTiO3 is a good anode catalyst for conversion of methane in SOFC, especially in H2S-containing atmospheres. Compared with SrTiO3 and La2Ti2O7 samples, the BaTiO3−based fuel cell has higher resistance to carbon deposition, better electrochemical performance and much higher stability during long term operation. A maximum power density of 135 mW cm−2 was achieved at 900 °C with 0.5% H2S–CH4 in a fuel cell having a 300 μm thick YSZ electrolyte. High catalytic activity for methane conversion, mixed electronic and ionic conductivity, and the surface basicity of BaTiO3 unexpectedly provides promising performance as anodes in SOFC. [Copyright &y& Elsevier]

Abstract: Electrochemical performance, impedance spectroscopy and carbon tolerance analysis show, for the first time, that molybdenum carbide has great potential for application as anode catalyst in proton-conducting solid oxide fuel cells. Ethylene and stable power density are coproduced from ethane in proton-conducting SOFC with molybdenum carbide as anode catalyst and BCZY as electrolyte. [Copyright &y& Elsevier]

Abstract: Ethane and electrical power are co-generated in proton ceramic fuel cell reactors having Cr2O3 nanoparticles as anode catalyst, BaCe0.8Y0.15Nd0.05O3−δ (BCYN) perovskite oxide as proton conducting ceramic electrolyte, and Pt as cathode catalyst. Cr2O3 nanoparticles are synthesized by a combustion method. BaCe0.8Y0.15Nd0.05O3−δ (BCYN) perovskite oxides are obtained using a solid state reaction. The power density increases from 51mWcm−2 to 118mWcm−2 and the ethylene yield increases from about 8% to 31% when the operating temperature of the solid oxide fuel cell reactor increases from 650°C to 750°C. The fuel cell reactor and process are stable at 700°C for at least 48h. Cr2O3 anode catalyst exhibits much better coke resistance than Pt and Ni catalysts in ethane fuel atmosphere at 700°C. [ABSTRACT FROM AUTHOR]

Na‐O2 batteries are attractive for energy storage due to their high theoretical energy density. In order to alleviate Na dendrite formation, artificial protective coatings have been widely investigated in Na‐metal batteries (NMBs). Although it can be intuitive to expect transferable Na protection methodologies from NMBs to Na‐O2 batteries, the performance of anode protection coatings in Na‐O2 batteries remains obscure, because Na‐O2 batteries undergo a unique reaction mechanism involving superoxide. Here, the effect of superoxide crossover on the polymeric Na protection layer in Na‐O2 batteries is revealed, and an effective strategy to eliminate the implications of a superoxide‐sensitive protecting layer is proposed. Using polymeric alucone protected Na anode as an example, the alucone layer actually decomposes under superoxide attack and is incapable of facilitating long‐term cycling of Na‐O2 batteries in sharp contrast to its stable performance in NMBs. By blocking superoxide crossover with solid‐state electrolytes (SSEs), significantly improved Na‐O2 cell performance is demonstrated, recovering the Na dendrite suppressing effect of the alucone film. Benefiting from the synergistic effect of SSE and alucone layer, Na‐O2 batteries can achieve a long life of 325 cycles at 0.2 mA cm−2. This work indicates that the stability of the Na protection layer against superoxide should be taken into serious consideration. [ABSTRACT FROM AUTHOR]

Developing low temperature solid oxide fuel cells has been a prerequisite for commercialization. In response to this issue, a novel strategy for the directional construction of Ni/SDC anodes via magnetic field to achieve better polarization than the traditional Ni/SDC anodes in low operating temperature range (≤600°C) is exploited. In the condition of Ni and SDC particles lining up end to end to construct Ni/SDC anodes (Ni/SDC-B T), the polarization resistance (R p) of the remodeled Ni/SDC-B T in humidified H 2 are 0.263, 0.088 and 0.037 Ω cm2 at 500, 550 and 600°C, respectively. Furthermore, the optimization mechanism is proposed via the microstructure model. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Symmetrical solid oxide fuel cell (SOFC) adopting the same material at both electrodes is potentially capable of promoting thermomechanical compatibility between near components and lowering stack costs. In this paper, MnCr 2 O 4 –Gd 0.1 Ce 0.9 O 2-δ (MCO-GDC) composite electrodes prepared by co-infiltration method for symmetrical electrolyte supported and anode supported solid oxide fuel cells are evaluated at a temperature range of 650–800 °C in wet (3% H 2 O) hydrogen and air atmospheres. Without any alkaline earth elements and cobalt, the co-infiltrated MCO-GDC composite electrode shows excellent activity for oxygen reduction reaction but mediocre activity for hydrogen oxidation reaction. With MCO-GDC as the cathode, the Ni-YSZ (Y 2 O 3 stabilized ZrO 2) anode supported asymmetrical cell demonstrates a peak power density of 665 mW cm−2 at 800 °C. The above results suggest MCO-GDC is a promising candidate cathode material for solid oxide fuel cells. • MnCr 2 O 4 is chemically stable at typical dual atmospheres of SOFC. • Co-infiltration promotes the performance of MnCr 2 O 4 -GDC composite electrode. • MnCr 2 O 4 -GDC exhibits reasonable activity as cathode. • Anode supported cell achieves a peak power density of 665 mW cm−2 at 800 °C. [ABSTRACT FROM AUTHOR]

The hollow Si nanospheres modified by the mechanically robust titanium dioxide (TiO 2 ) shell and the uniform carbon layer are intentionally designed and successfully prepared as the anode active material of high performance lithium-ion batteries. The effects of the robust TiO 2 shell and the uniform carbon layer on the structure and electrochemical performances for the Si@TiO 2 @C nanospheres are studied in detail by X-ray photoelectron spectroscopy, transmission electron microscopy, X-ray diffraction and charge/discharge tests. The results show that the hollow structure of the Si core can spontaneously absorb the huge volume expansion stress, the robust TiO 2 shell is used as a compact fence to promote the expansion towards the interior of the Si cavity instead of the exterior in the processes of charge/discharge, and the uniform carbon layer can effectively enhance the electrical conductivity and further control the integrity and stability of the well-wrapped core-shell-shell framework. Typically, the resultant hollow Si@TiO 2 @C nanospheres exhibit a high initial discharge capacity of 2557.1 mAh g −1 with coulombic efficiency of 86.06% as well as a large recuperative discharge capacity of 1270.3 mAh g −1 after 250 cycles at 1 A g −1 with a mean coulombic efficiency of 99.53%. Therefore, the hollow Si@TiO 2 @C nanospheres prepared by one-step sol-gel coating process show outstanding electrochemical properties and are considered as a prospective candidate to the adhibitions of the anode material for new generation power LIBs. [ABSTRACT FROM AUTHOR]

In situ exsolution of Co nanoparticles on perovskite framework has been successfully synthesized by firing the porous precursor SrMo 0.8 Co 0.1 Fe 0.1 O 3-δ (SMCFO) in reducing flow at 850 °C. A structure transformation (from mixed to pure cubic phase) and the growth of Co nanoparticles are observed in H 2 atmosphere. This leads to an increase in the oxygen vacancy content, which is beneficial to the electrical conduction and catalytic activity towards the oxidations of H 2 and C 2 H 6 . Moreover, this material exhibits good redox reversibility under the condition of multiple reduction and re-oxidation cycles, as confirmed by the thermogravimetric analysis (TGA) measurements. A protonic fuel cell (PFC) built with this newly developed material shows a comparable electrocatalytic activity in both C 2 H 6 and H 2 atmospheres while a considerably high power density of 377 mW cm −2 is achieved in H 2 and 268 mW cm −2 in C 2 H 6 at 750 °C. In addition, C 2 H 4 yield in the cell with Co-SMCFO as anode is considerably improved (11.9%–37.8% at 650–750 °C) with respect to the widely used chromium oxide. The good electrochemical performance, the improved C 2 H 6 partial dehydrogenation ability and the negligible carbon formation in the Co-SMCFO anode are the strong indications that the SMCFO is a promising catalyst for the cogeneration of C 2 H 4 and electricity, and can also be potentially utilized in the PFC directly fueled with hydrocarbon. [ABSTRACT FROM AUTHOR]

The ideal solid oxide fuel cells (SOFCs) can be powered by readily available hydrocarbon fuels containing impurities. While this is commonly recognized as a key advantage of SOFC, it also, together with the elevated operating temperature, becomes the main barrier impeding the in-situ or operando investigations of the anode surface chemistry. Here, using a well-designed quenching experiment, we managed to characterize the near-surface structure of La 0.4 Sr 0.6 TiO 3+δ (LST) anode in SOFCs fuelled by H 2 S-containing methane. This new method enabled us to clearly observe the surface amorphization and sulfidation of LST under simulated SOFC operating conditions. The ∼1 nm-thick two dimensional sulfur-adsorbed layer was on top of the disordered LST, containing –S, –SH and elemental sulfur species. In SOFC test, such “poisoned” anode showed increased performances: a ten-fold enhanced power density enhancement (up to 30 mW cm −2 ) and an improved open circuit voltage (from 0.69 V to 1.17 V). Moreover, its anodic polarization resistance in methane decreased to 21.53 Ω cm 2 , a difference of 95% compared with the sulfur-free anode. Control experiments confirmed that once the adsorbed sulfur species were removed electrochemically, methane conversion slowed down simultaneously till full stop. [ABSTRACT FROM AUTHOR]

[Display omitted] • The K+ storage performance of one-dimensional P3BT@CNT is superior to previous organic PIBs anode materials. • The strong π-π interaction between P3BT and CNT enables the superior cycling stability. • The cation-π interaction between K+ and P3BT is enhanced by the addition of CNT. Potassium ion batteries (PIBs) are a potential alternative to lithium ion batteries (LIBs)for energy preservation usage. The risks related to the highly active K metal have aroused the exploration of alternative high-performance anode materials for PIBs. Herein, the carbon-nanotube-cored poly(3-butylthiophene) (denoted as P3BT@CNT) is proposed as a one-dimensional (1D) nanohybrid strategy to develop an advanced PIB anode. The superior K+ storage performance of P3BT@CNT has been demonstrated via a combination of experiments and theoretical calculations. CNTs in this nanohybrid play an important role on enhancing the electrochemical performances, providing macroscopical profits and interacting with P3BT in molecular level. The K+ storage mechanism of cation-π effect between K+ and π-electrons of thiophene ring is proposed. [ABSTRACT FROM AUTHOR]

A layered Mo doped Pr 0.5 Ba 0.5 MnO 3−δ (Mo-PBMO) double perovskite oxide was prepared by a modified sol–gel method and the properties of the fabricated material are characterized by various technologies. The results of X-ray diffraction (XRD), H 2 -temperature programmed reduction (H 2 -TPR), NH 3 -temperature programmed desorption (NH 3 -TPD), and thermogravimetric analysis (TGA) demonstrate that the treatment in reducing atmosphere at high temperature lead to a significant phase transformation of the material to a single cubic phase as well as with the Mo in multiple oxidized states. Such character leads to the production of large amount of oxygen deficiency with facilitated oxygen diffusion. The electrochemical performance tests of half-cell and single cell SOFCs exhibit the promoted effect of Mo on catalytic activity for the oxidation of H 2 and CH 4 , indicating that Mo-PBMO could serve as an anode material candidate for SOFCs. [ABSTRACT FROM AUTHOR]

A site deficient La 0.2 Sr 0.7 TiO 3−δ (LST A ) and a highly proton conductive electrolyte BaCe 0.7 Zr 0.1 Y 0.2 O 3−δ (BCZY) are synthesized by using solid state reaction method. The performance of the electrolyte-supported single cell, comprised of LST A + Cr 2 O 3 + Cu//BCZY//(La 0.60 Sr 0.40 ) 0.95 Co 0.20 Fe 0.80 O 3−δ (LSCF)+BCZY, is fabricated and investigated. LST A shows remarkably high electrical performance, with a conductivity as high as 27.78 Scm −1 at 1150 °C in a 10% H 2 /N 2 reducing atmosphere. As a main anode component, it shows good catalytic activity towards the oxidation of ethane, causing the power density to considerably increase from 158.4 mW cm −2 to 320.9 mW cm −2 and the ethane conversion to significantly rise from 12.6% to 30.9%, when the temperature increases from 650 °C to 750 °C. These changes agree well with the polarization resistance which dramatically decreases from 0.346 Ωcm 2 to 0.112 Ωcm 2 . EDX measurement shows that no element diffusion exists (chemical compatibility) between anode (LST A + Cr 2 O 3 +Cu) and electrolyte (BCZY). With these properties, the pure phase LST A is evaluated as a high electro-catalytic activity anode material for ethane proton conducting solid oxide fuel cell (PC-SOFC). [ABSTRACT FROM AUTHOR]

Active anodes were fabricated via wet chemical impregnation of optimized amount of La 0.4 Sr 0.6 TiO 3 (L4ST) into La 0.4 Ce 0.6 O 1.8 (LDC) pre-infiltrated porous yttria-stabilized zirconia (YSZ) matrix. Impregnations of 10 wt% LDC with 16 wt% L4ST significantly improved the performance of the fuel cell from 48 mW cm −2 for pure L4ST to 161 mW cm −2 for LDC–L4ST at 900 °C in H 2 . The contribution of the pre-loaded LDC to this improvement was investigated using electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) as well as transmission electron microscopy (TEM). The measurement results indicated that pre-infiltrated LDC increased the activity of the anode more effectively by decreasing the total polarization resistance of the cell from 3.3 Ω cm 2 to 1.0 Ω cm 2 in humidified H 2 at 900 °C. More importantly, the LDC nano-deposits (<20 nm) behaved as an effective “adhesive” that substantially enhanced the wettability of L4ST on YSZ matrix, resulting in finer and more uniform structure of L4ST infiltrates. The LDC–L4ST cells also demonstrated significantly improved performances in 0.5% H 2 S–H 2 and 0.5% H 2 S–CH 4 with higher stability than cells with pure L4ST anode. [ABSTRACT FROM AUTHOR]

Abstract: The effects of H2S and H2O in the methane feed on carbon deposition in a La0.4Sr0.5Ba0.1TiO3 (LSBT) anode-based solid oxide fuel cell were investigated in this work under different operating conditions. Characterization was done using a combination of electrochemical, Fourier transform infra-red spectroscopy (FTIR), temperature-programmed oxidation (TPO) and X-ray photoelectron spectroscopy (XPS) measurements. As expected, carbon accumulation became more severe with increasing exposure time and operating temperature, but less severe in the presence of a current and/or steam. Addition of 0.5% H2S to the feed increased carbon accumulation and this carbon could not be removed effectively by co-feeding a small amount of steam to the anode. The resulting carbon was, however, easier to remove with oxygen as compared to that deposited by the H2S-containing dry feed. [Copyright &y& Elsevier]

Ethane can be electrochemically dehydrogenated and converted into electric energy via protonic ceramic fuel cells to obtain highly selective chemical ethylene without producing carbon oxides. This novel conversion path relies on a highly catalytically active anode for promote the cracking of ethane. In responding to this requirement, a previously characterized anode material (La 0.6 Sr 0.4) 0.95 Fe 0.9 Mo 0.1 O 3-δ (LSFM) is modified by doping with active metals (Ni and Co) at the B-site of a perovskite structure. The (La 0.6 Sr 0.4) 0.95 Fe 0.7 Ni 0.2 Mo 0.1 O 3-δ (LSFNM), (La 0.6 Sr 0.4) 0.95 Fe 0.7 Co 0.2 Mo 0.1 O 3-δ (LSFCM) and (La 0.6 Sr 0.4) 0.95 Fe 0.7 Co 0.1 Ni 0.1 Mo 0.1 O 3-δ (LSFCNM) electrode materials are synthesized by the combustion method. The subsequent in situ exsolution of the FeNi, CoFe and NiCoFe alloy nanoparticles in a reducing atmosphere improves the catalytic performance of the resultant electrodes. The obtained data show that the maximum power densities of single cells constructed using LSFCNM as an anode material at 750 °C reach 328 mW cm−2 and 258 mW cm−2 in H 2 and C 2 H 6 , respectively. Meanwhile, the ethane conversion process yields ∼44% under a constant current. The significantly higher performance of these cells than that achieved with single cells using LSFNM and LSFCM as anode materials, respectively, indicate that the NiCoFe ternary alloy offers better synergistic catalytic activity than that of the CoFe and FeNi binary alloys. [Display omitted] •In situ precipitation ternary alloys by doping active metals Ni and Co elements. •The segregation of nanoparticles obtains abundant active oxygen vacancies. •The thermal catalytic and electrochemical properties are significantly improved. •Ethylene and electricity can be coproduced in ethane-fueled protonic ceramic fuel cells. [ABSTRACT FROM AUTHOR]

Abstract: The present study reports the effect of fabrication conditions and environmental conditions, such as anodization voltage and aging period, on the wetting of zirconium dioxide nanotube (ZrNT) surfaces. Comparing with intact zirconium foil, which was inherently less hydrophilic, possessing an approximate contact angle of 60–70°, the as-formed ZrNT surfaces were much hydrophilic with an approximate contact angle of 18°. However, the hydrophilicity of the surfaces exhibited a decrease when the nanotubular opening diameters decreased while maintaining the nanotubular layer thickness. This phenomenon was attributed to the balance of capillary force and force generated by compressed air in the ZrNTs. The annealing treatment further increased the hydrophilic property of the ZrNTs. In addition, it was found that the wettability of ZrNTs, when aged in air over a period of 105days, demonstrated a decrease in hydrophilic characteristics and exhibited, to some extent, an increase in hydrophobic characteristics. It was believed that the surface wettability was able to be changed due to the decreasing content of hydroxyl groups in ambient atmosphere. This work can provide guidelines for improving the structural and environmental conditions responsible for changing surface wettability of ZrNT surfaces for biomedical application. [Copyright &y& Elsevier]

Abstract: Cu surface modified nickel foam is obtained by heating copper coated nickel foam in a reducing atmosphere. La0.75Sr0.25Cr0.5Mn0.5O3−δ (LSCM) perovskite oxide is prepared using a sol–gel combustion method. The modified foams and LSCM powders exhibit excellent resistance to carbon deposition in syngas at high temperatures. Furthermore, Cu modified foams show better mechanical strength compared to bare Ni foam, which readily cracks after exposure to syngas at high temperature. LSCM retains its perovskite structure during exposure to syngas or carbon monoxide at 900 °C for 10 h. Cu surface modified Ni foam current collector demonstrates good chemical compatibility with LSCM in syngas atmosphere at high temperature. Syngas solid oxide fuel cells (SOFCs) are assembled using Cu modified Ni foam anode current collector, LSCM anode catalyst, YSZ electrolyte, and porous Pt cathode. The present fuel cell provides similar power density to one with gold anode current collector and has excellent stability during operation at 900 °C. [ABSTRACT FROM AUTHOR]

Tungsten-based materials are very promising anode materials for lithium-ion batteries. Their lithiation processes involve two types of reactions, intercalation and conversion reactions, which occur sequentially according to the degree of lithiation. However, the boundary between these two reactions and their effects on the overall electrochemical performance still need more in-depth understanding and description. Herein, an X-ray diffraction and first-principles calculation were combinedly implemented to reveal the lithiation processes of the monoclinic W 18 O 49. The transformation between intercalation and conversion reactions was found to be dependent on the number of intercalated Li atoms. The in-situ XRD analysis shows structural phase transformations occurred as the deep charge-discharge was performed, which corresponding to the structure of Li x W 18 O 49 (x > 22) revealed by the first-principles calculation. Moreover, excellent stability of battery capacity was found in the shallow charge-discharge, whereas not in the deep charge-discharge. Based on this study, we comprehensively deciphered the factors that affect the electrochemical performance and reaction mechanism of W 18 O 49 with lithium. We hope this study could contribute to the application of W 18 O 49 and similar transition metal oxide anode materials for lithium ion batteries. [ABSTRACT FROM AUTHOR]

Anode materials with excellent catalytic activity, good stability, and enhanced tolerance to carbon deposition are highly desired for solid oxide fuel cells (SOFCs). Herein, CoFe (CF) nanoalloy catalysts are homogeneously in-situ embedded on Sr 3 FeMoO 7 (RP-SFM) efficient electrically conductive perovskite matrix through reduction of Sr 2 FeMo 2/3 Co 1/3 O 6−δ precursor. The particle size of CoFe alloy is in the range of 10–50 nm, and the electrical conductivity enhances from about 8 to 17 S cm−1 to 49-63 S cm−1 after Sr 2 FeMo 2/3 Co 1/3 O 6−δ reduction. The maximum power density of SOFCs with the RP-SFM@CF-SDC(Sm 0.2 Ce 0 · 8 O 1.9) composite anode in H 2 fuel reaches to 2.12 W cm−2 at 850 °C, which is about 1.4 times than that of the SOFCs with traditional Ni-SDC anode. Moreover, the RP-SFM@CF-SDC anodes also demonstrate excellent resistance to carbon deposition and high power density when C 3 H 8 hydrocarbon is used as fuel. The improved catalytic activity results from the efficient electronic/ion conductive paths, abundant CoFe active sites, together with the enlarged trip phase boundaries (TPBs). Image 1 • CoFe(CF) nanoalloy are homogeneously embedded on the layered perovskite RP-SFM. • RP-SFM@CF anode exhibits excellent catalytic activity and good structural stability. • RP-SFM@CF-SDC anode exhibits higher electrochemical performance than Ni-SDC. • The improved performance results from the abundant CoFe active sites and TPBs. [ABSTRACT FROM AUTHOR]