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The components and structures of the solid-electrolyte interphase (SEI) are critical for stable cycling of lithium metal batteries (LMBs). LiF has been widely studied as the dominant component of SEI, but Li2O, which has a much lower diffusion barrier for Li+, has rarely been investigated as the dominant component of SEI. The effect of Li2O-dominated SEI on electrochemical performance still remains elusive. Herein, an ultrastrong coordinated cosolvation diluent, 2,3-difluoroethoxybenzene (DFEB), is designed to modulate solvation structure and tailor Li2O-dominated SEI for stable LMBs. In the DFEB-based LHCE (DFEB-LHCE), DFEB intensively participates in the first solvation shell and synergizes with FSI–to tailor an Li2O-dominated inorganic-rich SEI which is different from the LiF-dominated SEI formed in conventional LHCE. Benefiting from this special SEI architecture, a high Coulombicefficiency (CE) of 99.58% in Li||Cu half cells, stable voltage profiles, and dense and uniform lithium deposition, as well as effective inhibition of Li dendrite formation in the symmetrical cell, are achieved. More importantly, the DFEB-LHCE can be matched with various cathodes such as LFP, NCM811, and S cathodes, and the Li||LFP full cell using DFEB-LHCE possesses 85% capacity retention after 650 stable cycles with 99.9% CE. Especially the 1.5 Ah practical lithium metal pouch cell achieves an excellent capacity retention of 89% after 250 cycles with a superb average CE of 99.93%. This work unravels the superiority of the Li2O-dominated SEI and the feasibility of tailoring SEI components through modulation of solvation structures.

Solid-state lithium batteries with solid polymer electrolytes have recently attracted extensive attention due to their promising potential in high energy density and safety. However, the principal issues plaguing the solid polymer electrolytes are their restricted ionic conductivities at ambient temperature and the limited tolerance to the widely used high-voltage cathodes (such as LiNi0.8Mn0.1Co0.1O2, NCM811), thus limiting their practical applications seriously. In this regard, a superior polymer-in-salt solid electrolyte from poly(caprolactone)-graft-polyrotaxane (PGPE) is developed for high-voltage lithium batteries operated at room temperature. The PGPE displays remarkable electrochemical properties at room temperature, with an exceptional ionic conductivity of 4.89 × 10–4S cm–1and a lithium-ion transference number of approximately 0.64, stemming from the rapid segmental motions of PCL sidechains by the enhanced dynamics of the cyclic molecules along the axial polymer chain of polyrotaxane. More importantly, the PGPE demonstrates a high electrochemical oxidation voltage of ∼4.7 V, suggesting the excellent electrochemical stability of PGPE against the NCM811-based cathode. Owing to the dense LiF-rich CEI self-generated on the NCM811 particles in the cathode, the transition metal ion diffusion is successfully constrained and the PGPE is well protected from continuous decomposition. The PGPE also shows superior interfacial stability between the metallic Li and the electrolyte. As a result, the all-solid-state NCM811|PGPE|Li cell exhibits superior discharge capacity (196 mAh g–1) and extraordinary long-term cycling stability (74% capacity retention at 150 cycles) at 30 °C.

Lithium metal is widely regarded as the “ultimate” anode for energy-dense Li batteries, but its high reactivity and delicate interface make it prone to dendrite formation, limiting its practical use. Inspired by self-assembled monolayers on metal surfaces, we propose a facile yet effective strategy to stabilize Li metal anodes by creating an artificial solid electrolyte interphase (SEI). Our method involves dip-coating Li metal in MPDMS to create an SEI layer that is rich in inorganic components, allowing uniform Li plating/stripping under a low overpotential over 500 cycles in carbonate electrolytes. In comparison, pristine Li metal shows a rapid increase in overpotential after merely 300 cycles, leading to failure soon after. Molecular dynamics simulations demonstrate that this uniform artificial SEI suppresses Li dendrite formation. We further demonstrated its enhanced stability pairing with LiFePO4and LiNi1–x–yCoxMnyO2cathodes, highlighting the proposed strategy as a promising solution for practical Li metal batteries.

The synergetic effect between ternary PtCoNi IMC NPs and the Co-Ny/Ni-Nzdual active centers results in the outstanding activity and stability of the catalyst towards ORR.

Here we present an innovative, universal, scalable, and straightforward strategy for cultivating a resilient, flexible lithium-ion battery (LIB) based on the bacterial-based self-growing approach. The electrodes and separator layers are integrated intrinsically into one unity of sandwich bacterial cellulose integrated film (SBCIF), with various active material combinations and tailored mechanical properties. The flexible LIB thereof showcases prominent deformation tolerance and multistage foldability due to the unique self-generated wavy-like structure. The LTO|LFP (Li4Ti5O12and LiFePO4) SBCIF-based flexible LIB demonstrates reliable long-term electrochemical stability with high flexibility, by exhibiting a high capacity retention (>95%) after 500 cycles at 1C/1C after experiencing a 10 000 bending/flattening treatment. The LTO|LFP SBCIF battery subjected to a simultaneous bending/flattening and cycling experiment shows an extraordinary capacity retention rate (>68%) after 200 cycles at 1C/1C. The biobased self-growing approach offers an exciting and promising pathway toward the tailored, integrated high-performance flexible LIBs.

Further application of electric vehicles (EVs) in frigid regions is hindered by the diminished performance of lithium-ion batteries (LIBs) at sub-zero temperatures. Developing efficient heat preservation strategies has significant implications for the broad application of EVs and LIBs. This study focuses on passive heat preservation strategies (PHPS) for battery packs in frigid environments (−30 °C). A validated 3D battery pack heat preservation model integrated with airflow is constructed in this paper, and the model analysis results indicate that arranging aerogels at the pack level provides superior heat preservation compared to cell and module levels. Additionally, the influence of flow field distribution (FFD) schemes on heat preservation performance is discovered. Both experimental and simulation results confirm that the proposed scheme can optimize the cooling rate to about 2.3 °C/h. Commencing from an initial temperature of 30 °C, extending the battery pack retention time above 0 °C to over 12 h under −30 °C can significantly expand the application of electric vehicles in frigid regions. This paper explores the primary factors affecting the heat dissipation of battery packs in the frigid temperature environment, which have great significance in guiding the heat preservation design of battery systems.

As a promising high energy density electrode material for rechargeable batteries, lithium (Li) metal is still suffering from air/water instability due to its highly reactive nature. In addition, the Li dendrite issue in Li metal batteries needs to be resolved to ensure the safety of batteries and for wide applications. Herein, we demonstrate that a simple compact GaOxlayer formed using liquid metal (LM) can act as an artificial solid electrolyte interphase to block moisture and oxygen in the air from corroding the lithium metal. Interestingly, GaOxthat covered the electrode effectively inhibits Li dendrite growth in electrochemistry cycling, ensuring the safety of Li metal batteries. The exposed composite Li metal anode (exposed under ambient air with relative humidity (RA) ≈ 75% for 5 h) not only shows a superior stability (symmetrical cell) but also delivers an elevated cycling stability (>500 cycles at 0.5 and 1 C) with a sulfur@C cathode in the full-cell configuration. Our work provides a new pathway for the large-scale applications of the air/water-tolerant Li metal anode in rechargeable batteries.

In this study, a novel aqueous polymeric binder is developed to suppress the shuttle effect of polysulfides and enhance the electrochemical performance of Li–S batteries.

Electrolyte design strategies are closely related to the capacities, cycle life and safety of sodium–ion batteries. In this study, we aimed to optimize electrolyte with the focus on engineering aspects. The basic physicochemical properties including ionic conductivity, viscosity, wettability and thermochemical stability of the electrolytes using NaPF6as the solute and the mixed solvent with different components of EMC, DMC or DEC in PC or EC were systematically measured. Ah pouch cell with NaNi1/3Fe1/3Mn1/3O2/hard carbon electrodes was used to evaluate the performance of the prepared electrolytes. By using the Inductive Coupled Plasma Emission Spectrometer (ICP), X-ray photoelectron spectroscopy (XPS), Thermogravimetric-differential scanning calorimetry (TG-DSC) and Accelerating Rate Calorimeter (ARC), we show that an optimized electrolyte can effectively promote the formation of a protective interfacial layer on two electrodes, which not only retards parasitic reactions between the electrodes and electrolyte but also suppresses dissolution of metal ions from the cathode. With an optimized electrolyte, a NaNi1/3Fe1/3Mn1/3O2/hard carbon cell can attain 56.16% capacity retention under the low temperature of −40 °C, and can be able to retain 80% capacity retention after more than 2500 cycles while presenting excellent thermal safety.

Lithium–sulfur batteries (LSBs) have drawn tremendous attention for their superior theoretical energy density. Nevertheless, the “shuttle effect” originating from the dissolution and migration of lithium polysulfide (LiPS) in electrolytes limits the cycling stability of LSBs. To deal with this challenge, a biopolymer network PPG with a three-dimensional (3D) cross-linked structure, on the basis of guar gum (GG), phytic acid (PA), and soy protein isolate (SPI), has been explored as a cathode binder for LSBs. The robust adsorption ability to capture LiPS presented by the PPG binder has been demonstrated through the ultraviolet–visible (UV–vis) measurement and further been certified by calculation with the density functional theory (DFT). Its outstanding mechanical and adhesion performance is also beneficial to sustain the integrality of sulfur electrodes during the cycle life test. PPG binder-based LSBs exhibit significant promotion in prolonged cycling tests with a 79.7% capacity retention after 700 cycles at 1 C. The capacity of PPG binder-based LSBs can still maintain 933.6 mAh g–1(at 0.1 C) after 50 cycles even with a high sulfur mass loading of 4.9 mg cm–2. This result demonstrates the significance of a natural polymer in the design of a binder for a sulfur cathode to achieve LSBs with splendid cycling performance.

Photocatalytic conversion of polyols to value-added products is of great interest for the utilization of biomass as a chemical feedstock. Current research focuses on boosting the reaction rate and selectivity by employing metal nanoparticles (NPs) as charge separators and cocatalysts. However, the promotional role of metal NPs in such photocatalytic processes still remains unclear because of the lack of mechanistic understanding. Here, we have explored the role of supported Pd and Au NPs on TiO2in photocatalytic glycerol conversion under water-free, deaerated conditions by in situspectroscopic methods. While the presence of Au NPs only results in partial conversion of glycerol at a low rate, Pd decoration promotes glycerol oxidation to a much higher conversion. In situmass and vibrational spectrometry reveals that Pd/TiO2exhibits faster cleavage of O–H and C–H bonds in both glycerol and the derived intermediates as compared to Au/TiO2, thus leading to a higher glycerol conversion accompanied by the formation of additional molecular hydrogen. X-ray photoelectron spectroscopy suggests that the preferential adsorption of glycerol on the surface of Pd viahydroxyl groups results in an enhanced interfacial charge transfer, thus yielding a better photocatalytic activity.

High-mass-loading electrodes with long-term stability have long been a great challenge for lithium–sulfur batteries (LSBs), since the conventional binders are unable to cope with the shuttling of lithium polysulfides and the structural damage in an electrode. Here, a novel water-based polymer, polyphosphate acid cross-linked chitosan ethylamide carbamide (PACEC), is developed as a binder to construct high-energy-density sulfur cathode and flexible LSBs. With a dual-cross-linked network, the PACEC shows excellent affinity with lithium polysulfides to relieve the shuttle effect and robust mechanical properties to stabilize the electrode. The sulfur cathode based on PACEC demonstrates a high sulfur loading of 14.8 mg cm–2, the areal initial capacity of 17.5 mAh cm–2, and Coulombic efficiency of 99.3%, while the amount of electrolyte is strictly limited to 6 μL mg–1. More importantly, a robust pouch cell with an area of 6 cm2and only 177% oversized lithium can successfully integrate the energy density of 6.5 mAh cm–2with the cycling retention per cycle of 99.74% during 270 cycles and flexibility at a curvature of 3 mm. This study provides inspirations for the design of eco-friendly polymer binders and paving new ways for the development of LSBs.

Solid electrolyte interphase (SEI) is crucial for suppressing Li dendrite growth in high-energy lithium metal (LiM) batteries. Unfortunately, the naturally formed SEI on the LiM anode surface in carbonate electrolytes cannot suppress Li dendrites, resulting in a continuous consumption of electrolytes and LiM during cycling. Artificial SEI normally lacks self-healing and self-regulating capability, gradually losing the effectiveness during cycling. In this work, we report the self-regulating phenomenon of LiRAP-ASEI that can effectively suppress Li dendrites and is investigated using in situ optical microscopy and COMSOL multiphysics simulation. The effectiveness of self-regulated LiRAP-ASEI is further evaluated in the most aggressive Li/sulfur cells with a lean electrolyte (10 μL mAh–1) and LiRAP-ASEI/LiM (2.5-fold excess of LiM). The LiRAP@Cu∥sulfur@C cells show a stable 3000 cycle life at a current density of 11.5 mA cm–2. The self-regulated phenomenon holds great promise for the development of high-energy-density LMBs.

Three-dimensional (3D) lithiophilic host is one of the most effective ways to regulate the Li dendrites and volume change in working Li metal anode. The state-of-the-art 3D lithiophilic hosts are facing one main challenge in that the lithiophilic layer would melt or fall off in high-temperature environment when using the thermal infusion method. Herein, a 3D porous CuZn alloy host containing anchored lithiophilic Zn sites is employed to prestore Li using the thermal infusion strategy, and a 3D composite Li is thus fabricated. Benefiting from the lithiophilic Zn sites with a strong adsorption capacity with Li, which is based on the analyses of the nucleation overpotential, binding energy calculation, and the operando optical observation of Li plating/stripping behaviors, facile uniform Li nucleation and dendrite-free Li deposition could be achieved in the interior of the 3D porous CuZn alloy host and the 3D composite Li shows remarkable enhancement in electrochemical performance.

Electrolytes in modern Li ion batteries (LIBs) rely on additives of various structures to generate key interphasial chemistries needed for desired performances, although how these additives operate in battery environments remains little understood. Meanwhile, these traditional additives face increasing challenges from emerging battery chemistries, especially those based on the nickel cathode (Ni ≥ 50%) or the metallic lithium anode. In this work, we report a new additive structure with the highest unsaturation degree known so far along with the in-depth understanding of its breakdown mechanism on those aggressive electrode surfaces. Tripropargyl phosphate (TPP) containing three carbon–carbon triple bonds was found to form dense and protective interphases on both NMC532 cathode as well as graphitic and metallic lithium anodes, leading to significant improvements in performances of both LIBs and lithium metal batteries (LMBs). Comprehensive characterizations together with calculations reveal how the unsaturation functionalities of TPP interact with these electrode chemistries and establish interphases that inhibit gas generation, suppress lithium dendrite growth, and prevent transition metal ion dissolution and deposition on the anode surface. The correlation established among the additive structure, interphasial chemistries, and cell performance will doubtlessly guide us in designing the electrolytes with atomistic precision for future battery chemistries.

In many applications, especially electrical submersible pump required remote operation of inverter via a long motor cable. The conventional control algorithm of induction motor (IM) didn’t operate effectively, which ignored the influence of the cable length, and didn’t consider the effect of long cable distribution parameters. A speed sensor technique was also difficult to achieve. In this paper, an improved speed sensorless vector control algorithm (ISSVCA) for IM based on long cable was proposed. Based on the analysis of long cable motor drive system of the inverter, the two-port πnetwork model of the long cable was established. The functional relationship between the voltage/current parameters of the two ports of the long cable and the cable distribution parameters was deduced. The function expression was transformed to the α− β stationary reference frame, the accurate motor terminal voltage/current was calculated, so that the flux model was constructed to realize the observation of the flux, accurate velocity identification, and closed-loop control of the torque, flux and current. Simulation and experimental results showed that the proposed ISSVCA based on long cable increased the starting electromagnetic torque, decreased speed dip and speed recovery time caused by sudden loads, reduced the DC current harmonics, and had good dynamic and static characteristics.

Nitrogen-doped carbon anode materials have been prepared by a hard-template (SiO2 nanoparticles) method, in which alkali lignin-derived azo polymer (AL-azo-NO2) was used as a low-cost carbon precursor. The as-prepared N-doped carbon materials show a honeycomb-like morphology with uniform nanopores. These materials are able to reversibly insert Na+ ions and show promising cycling performance. In particular, the porous carbon material with larger surface area and pore volume delivers a higher initial capacity of 205 mAh g[?]1 in the voltage range of 0.01-2 V at 50 mA g[?]1, compared to the material with lower surface area and pore volume (only 155 mAh g[?]1). The former also exhibits much better rate capability than the latter. Even at a high current density of 1 A g[?]1, it shows a high specific capacity of 101 mAh g[?]1 after 1100 cycles, which retains 92% of its initial capacity. Electrochemical impedance spectroscopy (EIS) results prove that the enhanced electrochemical performance is attributed to the improved Na+-ions kinetics in this material. This work presents an alternative approach for the synthesis of high-rate carbonaceous anode materials for sodium ion batteries from low cost and sustainable feedstock.

The invention of the saddle substantially improved horseback-riding, which not only revolutionized warfare, but also eased long-distance speedy movement across Eurasia. Here we present the first detailed construction analysis and absolute age determination of a well-preserved soft leather saddle recovered from the tomb of a female deceased at the Yanghai cemetery site in the Turfan Basin at the eastern end of the Tian Shan mountains. Compared with the oldest known saddle from the Scythian Pazyryk culture site Tuekta barrow no. 1 (430–420 BCE) in north-western Altai, the Yanghai specimen radiocarbon dated to 727–396 BCE (95.4% probability range) is contemporaneous or possibly older. The saddle features the basic elements of soft saddle construction that are still used today: two stuffed, wing-shaped hides sewn together along the outer edges and separated by a central gullet-like spacer and lens-shaped support elements, resembling knee and thigh rolls of modern saddles. Being a masterful piece of leather- and needlework, it is, however, less complex compared to Scythian saddles from the 5th–3rd centuries BCE. Another specimen from nearby Subeixi site, which is also described in detail for the first time in the present study, much closer resembles the Pazyryk saddles in shape, size and structure. In Yanghai, equestrian paraphernalia appear in the grave assemblages during the entire burial period (ca. 1300 BCE to 200 CE), although in higher numbers only from ca. 300 BCE. In the same way, the burial of horses was not common until then. Despite the generally very good preservation of leather, only two saddles were discovered in Yanghai which makes them an exception rather than the norm and raises the question of whether these saddles were acquired from more specialized horse breeders, riders, and saddlers in the North.

Silicon is a promising candidate for negative electrodes due to its high theoretical specific capacity (~ 3579 mA h g−1) and low lithiation potential (~ 0.40 V vs. Li). However, its practical applications in battery have been inhibited by the large volume change (~ 400%) induced by Li+-insertion into Si lattices. Here, we attempt to resolve this issue at a fundamental level, and report for the first time a novel liquid metal (LM)-mediated spontaneous repairing conductive-additive-free Si anode for Li-ion battery. The fluidity of LM ensures the eternal contact between Si and the conducting-network during its repeated electrochemical reactions. The as-prepared nano-composite of LM/Si leads to superior performances as characterized by high capacity utilization (2300 mA h g−1at 500 mA g−1), long-term stability (968 mA h g−1after 1500 charge-discharge cycles at 8 A g−1with 81.3% retention), high rate capability (360 mA h g−1at 20 A g−1, equivalence of 55 C, or full charge/discharge in 65 s), and, in particular, an extra-ordinarily high initial coulombic efficiency (95.92%), which is not only the highest reported for Si to the best of our knowledge, but also higher than the mature graphitic carbon anodes. The unique approach described in this work not only resolves the basic stress challenges faced by the promising but often problematic alloy-type materials; in broader context it also provides a universal inspiration to all electrode materials whose electric properties suffer from extreme mechanic upheavals induced by the electrochemical strains during the cell reactions.

Alkali and alkaline ion substitutions enhance the electrochemical properties of P2 sodium layered oxide, while the effect on electrochemical property enhancement of alkali and alkaline ions co-substitution is still unclear. In this work, the structural and electrochemical properties of the Li alkali and Mg alkaline ions co-substituted P2 layered oxide Na0.67(Li0.5Mg0.5)0.1(Ni0.33Mn0.67)0.9O2are investigated in detail. Compared to the pristine and single-ion substituted materials, the co-substituted material shows an enhanced cycling performance with a reversible capacity of 127 mAh/g and a capacity retention of 75% over 100 cycles at 0.5C. Galvanostatic intermittent titration technique (GITT) and cyclic voltammetry (CV) results show that the Li and Mg synergistically improve the ion diffusion. Moreover, the structure stability is also improved by the Li and Mg co-substitution that is clarified by operando X-ray diffraction (XRD) measurements. These results explain the origin of the enhanced electrochemical properties of the Li/Mg co-substituted P2 layered oxides for sodium ion batteries.

We report here an intriguing hybrid conductive hydrogel as electrode for high-performance flexible supercapacitor. The key is using a rationally designed water-soluble ABA triblock copolymer (termed as IAOAI) containing a central poly(ethylene oxide) block (A) and terminal poly(acrylamide) (PAAm) block with aniline moieties randomly incorporated (B), which was synthesized by reversible additional fragment transfer polymerization. The subsequent copolymerization of aniline monomers with the terminated aniline moieties on the IAOAI polymer generates a three-dimensional cross-linking hybrid network. The hybrid hydrogel electrode demonstrates robust mechanical flexibility, remarkable electrochemical capacitance (919 F/g), and cyclic stability (90% capacitance retention after 1000 cycles). Moreover, the flexible supercapacitor based on this hybrid hydrogel electrode presents a large specific capacitance (187 F/g), superior to most reported conductive hydrogel-based supercapacitors. With the demonstrated additional favorable cyclic stability and excellent capacitive and rate performance, this hybrid hydrogel-based supercapacitor holds great promise for flexible energy-storage device.

Here we have obtained a temperature responsive melamine sponge with a controllable wettability between superhydrophilicity and superhydrophobicity by grafting the octadecyltrichlorosilane and thermoresponsive poly(N-isopropylacrylamide) (PNIPAAm) onto the surface of melamine sponge skeletons. The whole process included the silanization in which step the rough surface with low surface energy and the NH2were provided, and the atom transfer radical polymerization which ensured the successful grafting of PNIPAAm onto the skeleton’s surface. The product exhibits a good reversible switch between superhydrophilicity and superhydrophobicity by changing the temperature below or above the lower critical solution temperature (LCST, about 32 °C) of PNIPAAm, and the modified sponge still retains a good responsiveness after undergoing two temperature switches for 20 cycles. Simultaneously, the functionalized sponges could be used to absorb the oil under water at 37 °C, and they released the absorbed oil in various ways under water at 20 °C, showing wide potential applications including oil/water separation.

TTME plays a proactive role in the formation of the primary solvation shell and potentially contributes to a double-layer SEI, resulting in good high-voltage Li metal batteries cycling.

A key issue in the development of lithium ion batteries (LIBs) is the stability of the electrolyte, especially at high temperature. This research compares three electrolyte solvents with different cyclic carbonate structures, i.e.ethylene carbonate (EC), fluoroethylene carbonate (FEC) and difluoroethylene carbonate (DFEC) to investigate their effect on the performance of LiNi0.5Co0.2Mn0.3O2/artificial graphite lithium ion pouch cells at high temperature. The results point out that DFEC is the most effective solvent in preventing interfacial impedance growth and electrolyte decomposition, and improving cycling performance, with capacity retention of 85 % after cycling 500 times at 45 °C. Comprehensive characterizations reveal that DFEC forms effective interphases with high thermal stability on both cathode and anode. This work highlights the important role of DFEC in electrolyte formulations for high−energy−density LIBs at elevated temperature.

The lithium metal battery with solid-state polymer electrolyte (SPE) is a promising candidate for solid-state batteries with high safety and high energy density. However, the low room temperature ionic conductivity and poor electrolyte/electrode interfacial stability of the SPEs seriously hinder the practical application. Herein, we adopt a polymer-in-salt electrolyte (PISE) strategy on the comb-like polycaprolactone (PCL) to circumvent the low ionic conductivity and poor interfacial stability of the conventional SPE, thus enabling the full function of room temperature lithium metal batteries. The all-solid-state PISE exhibits a high ionic conductivity of 3.9 × 10−4 S cm−1at 30 °C, a superior lithium-ion transference number of 0.61 and an improved oxidative stability of ∼4.8 V vs Li/Li+. Due to the ultra-stable interface generated by the superconcentrated lithium salt, the all-solid-state LiFePO4∣∣Li cells exhibit prominent high cycling stability, with high capacity retention (92%) after 300 cycles at ambient temperature. The full function of the ambient temperature PISE offers a promising pathway towards high energy density and high safety room temperature LMBs.

We report a facile method to synthesize Fe3O4@polydopamine (PDA)-Ag core–shell microspheres. Ag nanoparticles (NPs) are deposited on PDA surfaces via in situreduction by mussel-inspired PDA layers. High catalytic activity and fast adsorption of a model dye methylene blue (MB) at different pH values are achieved mainly due to the presence of monodisperse Ag NPs and electrostatic interactions between PDA and MB. The as-prepared Fe3O4@PDA-Ag microspheres also show high cyclic stability (>27 cycles), good acid stability, and fast regeneration ability, which can be achieved efficiently within several minutes by using NaBH4as the desorption agent, showing great potentials in a wide range of applications.

The employment of localized high concentration electrolytes (LHCEs) has been demonstrated as an effective strategy for the fabrication of next-generation high-energy-density lithium metal batteries. However, the low ionic conductivity of LHCEs and their parasitic side reactions with lithium metal anodes severely hinder the cycling stability of lithium metal batteries. Herein, a partially fluorinated ether of bis (2,2-difluoroethyl) ether (BDE) is proposed as a bifunctional co-solvent to form novel LHCEs for realizing dendrite-free and long-term lithium metal batteries. The BDE co-solvent serves as a diluent to improve the ionic conductivity up to 6.4 mS/cm by dissociating lithium salt via weak interaction and decreasing the electrolyte viscosity. In addition, the BDE co-solvent could promote the formation of uniform lithium fluoride (LiF)-rich solid electrolyte interphase (SEI) to suppress the dendrite deposition by regulating the solvation shell structure, resulting in high Coulombic efficiency of 99.6%. As a result, the assembled full cell exhibits outstanding cycling stability (97% capacity retention after 200 cycles @0.5C) with high areal capacity (2 mAh/cm2) and high rate capability (2C) under practical conditions (50µm Li, lean electrolyte: 3g/Ah). We also demonstrate the real application of electrolyte with a commercial cathode in 320-mAh-level pouch cells.

In order to study the effect of molecular weight of polycarboxylate-type superplasticizer (PC) on the rheological properties of cement pastes, PCs with different molecular weights (low, medium, high) were synthesized, and used as superplasticizers for cement suspensions. The effect of molecular weight of PC on the zeta potential, adsorption, and rheological behaviour of the corresponding cement suspensions were investigated systematically. Among the PCs, PC with a medium molecular weight always produced the lowest apparent viscosity for cement pastes at the same shear rate. Compared to PC with a low molecular weight, PC with a high molecular weight presented a stronger initial dispersing ability and a weaker dispersing stabilizing ability for cement pastes. In addition, PC with a low molecular weight had an advantage over PC with a high molecular weight for reducing the viscosity of paste in the low added dosage or low water/cement ratio, but the latter had the advantage of reducing the viscosity of the paste when the added dosage or water/cement ratio was high. This understanding of the rheological properties of cement pastes incorporating PC will provide an important reference for the application and synthesis of PC with high efficiency.

Highlights:

A creative cooperative strategy involving silk fibroin/sericin is proposed for stabilizing high-performance flexible Li–S full batteries with a limited Li excess of 90% by simultaneously inhibiting lithium dendrites, adsorbing liquid polysulfides, and anchoring solid lithium sulfides.

Such fabric Li–S full batteries offer high volumetric energy density (457.2 Wh L−1), high-capacity retention (99.8% per cycle), and remarkable bending capability (6000 flexing cycles at a small radius of 5 mm). Abstract: Lithium–sulfur batteries are highly appealing as high-energy power systems and hold great application prospects for flexible and wearable electronics. However, the easy formation of lithium dendrites, shuttle effect of dissolved polysulfides, random deposition of insulating lithium sulfides, and poor mechanical flexibility of both electrodes seriously restrict the utilization of lithium and stabilities of lithium and sulfur for practical applications. Herein, we present a cooperative strategy employing silk fibroin/sericin to stabilize flexible lithium–sulfur full batteries by simultaneously inhibiting lithium dendrites, adsorbing liquid polysulfides, and anchoring solid lithium sulfides. Benefiting from the abundant nitrogen- and oxygen-containing functional groups, the carbonized fibroin fabric serves as a lithiophilic fabric host for stabilizing the lithium anode, while the carbonized fibroin fabric and the extracted sericin are used as sulfiphilic hosts and adhesive binders, respectively, for stabilizing the sulfur cathode. Consequently, the assembled Li–S full battery provided a high areal capacity (5.6 mAh cm−2), limited lithium excess (90%), a high volumetric energy density (457.2 Wh L−1), high-capacity retention (99.8% per cycle), and remarkable bending capability (6000 flexing cycles at a small radius of 5 mm).

Under the aegis of boron Lewis acids, prepared from either the vanol or vapol ligand, vinyl aziridinyl ketones can be obtained with a high degree of asymmetric induction from the catalytic asymmetric aziridination reaction (AZ) of imines and vinyl diazomethyl ketones. The products have potential as synthons for five-carbon chiral amines. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

This work studied the colloidal sphere formation, H-aggregation, and photoresponsive properties of an amphiphilic random copolymer functionalized with branched azo side chains (POAPB6P-AC). The colloidal spheres were prepared through gradual hydrophobic association of the polymer chains in THF−H2O media, which was induced by a continuous increase in the water content. The forming process and morphology of the colloidal spheres were characterized by DLS, SLS, and TEM. UV−vis spectroscopy was used to study the azo chromophore H-aggregation and structure variation in the colloid formation process by measuring the parameters such as max, the trans-to-cis photoisomerization rate, and the isomerization degree at the photostationary state. The results indicate that the colloidal sphere formation undergoes several different stages as the water content increases. The polymeric chains start to associate at the critical water content (CWC). CWC is related with the initial concentration of the polymer in THF and is estimated to be 23 vol % when the initial concentration is 1.0 mg/mL. When the water content increases beyond the CWC, more and more polymer chains change from “isolated” single chains to clusters of associated chains. When the water content reaches 37%, almost all polymer chains are involved in the clusters. As the water content further increases, the clusters experience a collapse caused by the strong hydrophobic interaction, which is indicated by a dramatic size contraction detected from the DLS measurements. When the water content reaches about 60 vol %, the azo chromophores of POAPB6P-AC start to form H-aggregates, which is indicated by a significant blue shift (from 360 to 339 nm) of the UV−vis maximum absorption band. The structure variation can also be detected from the photoisomerization behavior of the systems. When the water content changes from 50 to 60 vol %, both the trans-to-cis photoisomerization rate and the isomerization degree at the photostationary state decrease dramatically. Finally, when the water content increases from 95 to 100 vol %, the isomerization rate and degree significantly decrease again. In this stage, THF in the microphase is almost completely replaced by H2O, and colloidal structure is “frozen” because of the free volume decrease and chain entanglement. The above observations give insight into the occurrence of H-aggregation in colloids of amphiphilic azo polymers for the first time. The understanding can lead to further development in expanding functionalities of the photoresponsive colloidal spheres through manipulation of the chromophore aggregation.

Photoresponsive uniform colloidal spheres were constructed from an amphiphilic azobenzene-containing random copolymer, poly{2-[4-(phenylazo)phenoxy]ethyl acrylate-co-acrylic acid} (PPAPE), and were characterized by using TEM, SEM, AFM, SLS, and DLS measurements. The photoisomerization of the azobenzene units was studied and used as a tool to probe the structure variation during the sphere formation process. The spheres were formed through gradual hydrophobic aggregation of the polymeric chains in THF−H2O dispersion media, which was induced by a steady increase in the water content. The polymeric chains started to aggregate and form the colloidal spheres at the critical water content (CWC). CWC was related with the initial concentration of the polymer in the THF solution and estimated to be 25% (vol %) when the initial concentration was 1.0 mg/mL. The colloids grew as the water content increased above the CWC. After the water content reached 40−50% (vol %), both the trans-to-cis photoisomerization rate and the isomerization degree at the photostationary state decreased significantly as the water content increased. It indicated that the isomerization was hindered by the polymeric chain collapse and entanglement occurring at this stage of the sphere growth process. Upon UV light irradiation, the photoinduced deaggregation behavior of the spheres was controlled by the water contents of the dispersion media. The understanding obtained from above observations can give some insight into the mechanism for the formation of the uniform colloidal spheres from polydispersed random copolymers and can be used to control the colloidal structures by adjusting the preparation conditions.

A new dinoroleanane triterpene, remangilone D (4), and a new flavone 6 , have been isolated from the leaves of Physena madagascariensis (Physenaceae).

Ten guaianolides, including three previously unreported natural products, were isolated from the aerial parts of Cichorium intybus (Asteraceae), more commonly known as chicory. Two of the new compounds ( 8 and 9) were analogues of lactupicrin and 11/β,13-dihydrolactupicrin, respectively, with the C-15 oxidized to the aldehyde state. The third new natural product, which we have called mtybulide A (10), is an isomer of lactucin with the lactone closed to the C-8 oxygen rather than the C-6

No Abstract Supporting information for this article is available on the WWW under http://www.angewandte.com or from the author.

No Abstract Supporting information for this article is available on the WWW under http://www.angewandte.com or from the author.

UV-cured polymer electrolyte is synthesized via photo-polymerization of poly (ethylene glycol) methyl ether methacrylate and poly (ethylene glycol) diacrylate. The obtained polymer electrolyte exhibits a high ionic conductivity of 2.95 × 10?5S cm?1at 30 °C, a wide electrochemical stable window of up to 4.69 V (vs Li/Li+) and excellent compatibility against lithium metal electrode over 800 h. Besides, an integrated cathode/electrolyte interface is constructed through pouring the polymer electrolyte precursor onto the cathode layer. This kind of the integrated cell exhibits faster Li-ion diffusion in cathodic electrochemical reactions than conventional cells. Moreover, LiMn0.8Fe0.2PO4??Li cells with integrated cathode/electrolyte interface deliver a reversible capacity of 164.7 mAh g?1at 0.1C and retains a capacity of 134.4 mAh g?1after 240 cycles at 0.2C. Furthermore, the integrated cells show satisfactory performance under disastrous conditions, presenting their high safety. The UV cross-linked polymer electrolyte is a promising polymer electrolyte candidate for high energy density all-solid-state lithium metal batteries.

Nano approaches are practical strategies to boost the thermoelectric figure of merit due to the strong phonon scattering from the grain boundaries and nanoinclusions. Here, we have reported a strong phonon scattering at the heterogeneous interfaces of Mg2Sn/Mg3Sb2high-content nanocomposites (HCnCs). As a result, a significantly reduced lattice thermal conductivity of 1.09 W m–1K–1was observed in the equimolar Mg2Sn/Mg3Sb2HCnC, 80% lower than pure Mg2Sn and 25% lower than pure Mg3Sb2. As a result, a high ZT∼ 1.13 at 773 K was achieved in the Mg2Sn/Mg3Sb2HCnC. Furthermore, various defects, including solid solutions, nanoinclusions, and misfit dislocations, were observed in both the Mg3Sb2phase and the Mg2Sn phase through the microstructure characterization.

Electrolyte additives have been extensively used as an economical approach to improve Li-ion battery (LIB) performances; however, their selection has been conducted on an Edisonian trial-and-error basis, with little knowledge about the relationship between their molecular structure and reactivity as well as the electrochemical performance. In this work, a series of phosphate additives with systematic structural variation were introduced with the purpose of revealing the significance of additive structure in building a robust interphase and electrochemical property in LIBs. By comparing the interphases formed by tripropyl phosphate (TPPC1), triallyl phosphate (TPPC2), and tripropargyl phosphate (TPPC3) containing alkane, alkene, and alkyne functionalities, respectively, theoretical calculations and comprehensive characterizations reveal that TPPC3 and TPPC2 exhibit more reactivity than TPPC1, and both can preferentially decompose both reductively and oxidatively, forming dense and protective interphases on both the cathode and anode, but they lead to different long-term cycling behaviors at 55 °C. We herein correlate the electrochemical performance of the high energy Li-ion cells to the molecular structure of these additives, and it is found that the effectiveness of TPPC1, TPPC2, and TPPC3 in preventing gas generation, suppressing interfacial resistance growth, and improving cycling stability can be described as TPPC3 > TPPC2 > TPPC1, i.e., the most unsaturated additive TPPC3 is the most effective additive among them. The established correlation between structure–reactivity and interphase-performance will doubtlessly construct the principle foundation for the rational design of new electrolyte components for future battery chemistry.

ABSTRACT

Solid-state lithium metal batteries (LMBs) receive increasing attentions worldwide due to their safety and high energy density. Herein, the practical application of conversion reaction-type transition metal oxides (TMOs, Fe2O3, Mn2O3or CuO) as Li-free cathodes for solid-state LMBs is demonstrated for the first time, employing poly(ethylene oxide) (PEO), lithium garnet Li6.4La3Zr1.4Ta0.6O12or Li1.5Al0.5Ge1.5(PO3)4solid-state electrolytes (SSEs). The cathodes embody good interfacial compatibility with the SSEs, ensuring the excellent electrochemical performance of the TMOs/SSEs/Li solid-state cells. The as-prepared Fe2O3/PEO/Li cell measured at 60 °C delivers a high discharge capacity of 990 mAh g−1at 10 mA g−1, which is comparable to the Fe2O3liquid cell. When cycling at 200 mA g−1, a stable capacity of 733 mAh g−1is achieved at the 1,100thcycle for the Fe2O3/PEO/Li cell, while the Fe2O3liquid cell only sustains 860 cycles until failure. In order to further demonstrate the application feasibility, stable cycling of the Fe2O3/PEO/Li cells with high mass loading of 2.83 mg cm−2and thus high areal capacity of 1.67 mAh cm−2or with limited Li usage (150% in excess) is preliminarily achieved. In addition, the Fe2O3/PEO/Li pouch cells are assembled, which exhibit satisfied electrochemical performance. Moreover, poly(vinylidene difluoride) (PVDF)-based solid polymer electrolye is employed to make the Fe2O3solid-state cell work at 30 °C successfully. These results convince the great promise of TMOs in future high-energy-density solid-state LMBs.

High ionic conductivity is a prerequisite for the application of solid-state polymer electrolyte towards the safe and high energy density electrochemical devices. Here we report the preparation and properties of an in-situ polymerized comb-like copolymer-based SPE (PLA/PEG-SPE) with high ionic conductivity from methyl acrylate functionalized poly(D,L-Lactide) (PLAMA) and poly(ethylene glycol) methyl ether methacrylate (PEGMA). A remarkably high ionic conductivity value of 6.9 x 10[?]5 S cm[?]1 at ambient temperature and a maximum ionic conductivity of 4.3 x 10[?]4 S cm[?]1 at 60degC were detected, with an activation energy of 0.2 eV and a Li+ transference number (tLi+) of 0.36. The PLA/PEG-SPE exhibits a wide electrochemical stability window up to 4.6 vs. Li/Li+ and very good lithium metal electrode compatibility. Solid-state LiFePO4/SPE/Li cells with integrated cathode and lithium metal deliver superior cycling stability with high discharge capacities (149 mAh g[?]1 as the initial specific capacity) and high capacity retention (exceeded 82% of its initial specific capacity) at 0.2 C at 60degC. The solid-state cells are also capable of being cycled at room temperature at 0.2 C. This work highlights a facile, in-situ fabrication strategy involving a vinyl-functionalized PLA precursor that yields a high-performance ion-conducting membrane attractive for lithium metal battery applications.

High ionic conductivity is a prerequisite for the application of solid-state polymer electrolyte towards the safe and high energy density electrochemical devices. Here we report the preparation and properties of an in-situ polymerized comb-like copolymer-based SPE (PLA/PEG-SPE) with high ionic conductivity from methyl acrylate functionalized poly(D,L-Lactide) (PLAMA) and poly(ethylene glycol) methyl ether methacrylate (PEGMA). A remarkably high ionic conductivity value of 6.9 × 10−5S cm−1at ambient temperature and a maximum ionic conductivity of 4.3 × 10−4S cm−1at 60°C were detected, with an activation energy of 0.2 eV and a Li+transference number (tLi+) of 0.36. The PLA/PEG-SPE exhibits a wide electrochemical stability window up to 4.6 vs. Li/Li+and very good lithium metal electrode compatibility. Solid-state LiFePO4/SPE/Li cells with integrated cathode and lithium metal deliver superior cycling stability with high discharge capacities (149 mAh g−1as the initial specific capacity) and high capacity retention (exceeded 82% of its initial specific capacity) at 0.2 C at 60°C. The solid-state cells are also capable of being cycled at room temperature at 0.2 C. This work highlights a facile, in-situ fabrication strategy involving a vinyl-functionalized PLA precursor that yields a high-performance ion-conducting membrane attractive for lithium metal battery applications.

Nitrogen-doped carbon anode materials have been prepared by a hard-template (SiO2nanoparticles) method, in which alkali lignin-derived azo polymer (AL-azo-NO2) was used as a low-cost carbon precursor. The as-prepared N-doped carbon materials show a honeycomb-like morphology with uniform nanopores. These materials are able to reversibly insert Na+ions and show promising cycling performance. In particular, the porous carbon material with larger surface area and pore volume delivers a higher initial capacity of 205 mAh g−1in the voltage range of 0.01–2 V at 50 mA g−1, compared to the material with lower surface area and pore volume (only 155 mAh g−1). The former also exhibits much better rate capability than the latter. Even at a high current density of 1 A g−1, it shows a high specific capacity of 101 mAh g−1after 1100 cycles, which retains 92% of its initial capacity. Electrochemical impedance spectroscopy (EIS) results prove that the enhanced electrochemical performance is attributed to the improved Na+-ions kinetics in this material. This work presents an alternative approach for the synthesis of high-rate carbonaceous anode materials for sodium ion batteries from low cost and sustainable feedstock.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.