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All‐solid‐state lithium batteries (ASSBs) enabled by solid‐state electrolytes (SEs) including oxide‐based and sulfide‐based electrolytes have gained worldwide attention because of their intrinsic safety and higher energy density over conventional lithium‐ion batteries (LIBs). However, despite the high ionic conductivity of advanced SEs, ASSBs still exhibit high overall internal resistance, the most significant contributor of which can be ascribed to the cathode‐SE interfaces. This review seeks to clarify the critical issues regarding the cathode‐SE interfaces, including fundamental principles and corresponding solutions. First, major issues concerning electro‐chemo‐mechanical instability between cathodes and SEs and their formation mechanisms are discussed. Then, specific problems in oxides and sulfides and various solutions and strategies toward interfacial modifications are highlighted. Efforts toward the characterization and analysis of cathode‐SE interfaces with advanced techniques are also summarized. Finally, perspectives are offered on several problems demanding urgent solutions and the future development of SE applications and ASSBs. [ABSTRACT FROM AUTHOR]

Lithium‐ion batteries (LIBs) have been occupying the dominant position in energy storage devices. Over the past 30 years, silicon (Si)‐based materials are the most promising alternatives for graphite as LIB anodes due to their high theoretical capacities and low operating voltages. Nevertheless, their extensive volume changes in battery operation causes the structural collapse of Si‐based electrodes, as well as severe side reactions. In this review, the preparation methods and structure optimizations of Si‐based materials are highlighted, as well as their applications in half and full cells. Meanwhile, the developments of promising electrolytes, binders and separators that match Si‐based electrodes in half and full cells have made great progress. Pre‐lithiation technology has been introduced to compensate for irreversible Li+ consumption during battery operation, thereby improving the energy densities and lifetime of Si‐based full cells. More importantly, almost all related mechanisms of Si‐based electrodes in half and full cells are summarized in detail. It is expected to provide a comprehensive insight on how to develop high‐performance Si‐based full cells. The work can help us understand what happens during the lithiation process, the primary causes of Si‐based half and full cells failure, and strategies to overcome these challenges. [ABSTRACT FROM AUTHOR]

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 −1 at 500 mA g −1 ), long-term stability (968 mA h g −1 after 1500 charge-discharge cycles at 8 A g −1 with 81.3% retention), high rate capability (360 mA h g −1 at 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. [ABSTRACT FROM AUTHOR]

A novel lath-shaped CuO microassemble consisting of well-crystalized ultrafine nanocrystals was prepared by an ionothermal method with the assistance of ionic liquids ( ILs, 1-butyl-3-methylimidazolium tetrafluoroborate). As anode material of lithium ion batteries, the ILs-CuO exhibits high specific capacity, durability and good rate performance, superior to bare CuO. At a high current density of 1000 mA•g−1, after 100 cycles, ILs-CuO still retains a discharge capacity of 483.2 mAh•g−1. The improved electrochemical performances could be ascribed to the unique microscale lath-shape CuO assembles composed of ultrafine nanostructure. [ABSTRACT FROM AUTHOR]

A series of polyimides, which contain polyethylene glycol (PEG) segments with different molecular weight in the polymer chains, are synthesized through a facile one-pot method and characterized by Fourier transform infrared spectroscopy and hydrogen nuclear magnetic resonance spectroscopy. The main part of polyimides is originated from trimellitic anhydride chloride (TMAC) and 4,4′-methylenedianiline, onto which PEG segments are introduced through an esterification reaction with TMAC. These obtained polyimides, which acquire excellent water solubility after being neutralized by triethylamine, are applied as water-soluble binders to silicon negative electrodes for lithium ion batteries, and significantly improve the electrochemical performance of silicon anodes. Specially, the PI-200 (polyimide copolymerized with PEG-200) based silicon electrode exhibits a high initial discharge capacity of 2989.7 mAh g −1 and remains about 2235.5 mAh g −1 after 200 cycles at the current density of 0.1 C (420 mA g −1 ). [ABSTRACT FROM AUTHOR]

Although silicon (Si) anode has extremely high specific capacity, the damage to the electrode caused by the huge volume expansion greatly hinders its practical application in lithium-ion batteries. Aiming to alleviate this problem, a high-performance aqueous binder (AMNG) with gradient hydrogen bonding and flexible three-dimensional network structure is prepared by a one-pot method. Compared to the conventional linear polyacrylic acid (PAA) binder, the AMNG binder exhibits enhanced ionic conductivity and stress dissipation for Si nanoparticles, which is able to greatly reduce the side reactions caused by volume changes and considerably improve the electrochemical performance of Si anodes. As a result, the Si nanoparticles using the AMNG binder exhibit an initial discharge capacity as high as 3101 mAh g−1 with a Coulombic efficiency of 89.95%, and a capacity retention of 71.6% for 120 cycles, which are superior to the electrode using PAA, corresponding to 2832 mAh g−1, 88.37% and 28.1%, respectively. More prominently, the practical application of the AMNG binder is evaluated in high-mass-loading Si-based electrodes and even in full cells with LiFePO 4 , all showing satisfied performance. Therefore, this design approach is valuable as a reference for the preparation of commercial aqueous binders. [Display omitted] • An environmentally friendly binder is prepared by an aqueous one-pot method. • The binder embodies "gradient hydrogen bonding" and "elastic 3D network". • Nitrile groups and ether bonds boost the ionic conductivity of the binder. • The binder is universal for practical application of Si-based anodes. [ABSTRACT FROM AUTHOR]

Using conductive binders, instead of the traditional binders and conductive additives, is an effective way to increase the specific capacity and long cycle life of the silicon (Si) anode. However, the rigid conductive binders of Si anodes tend to form cracks during the repetitive huge volume changes of Si. Here, a novel n-type conductive binder, multi-block polymer of poly(1-pyrenemethyl methacrylate) and polybutadiene (PPy- b -PB) was designed. The polybutadiene (PB) rubber was incorporated into the conductive binder by combining condensation and reversible addition-fragmentation chain transfer polymerization. With high initial coulombic efficiency of 77.9%, the PPy- b -PB/Si anode possesses high reversible capacity (2274 mAh g−1) and capacity retention (87.1%) at the rate of 0.2 C (0.84 A g−1) after 200 cycles. The superior cyclic performance of the PPy- b -PB can be ascribed to the PB rubber, which enhanced the reversible deformation ability, flexibility, and adhesion length scale of the binder, without with a negligible change of the charge-transfer resistance for the anode. The original structure and the preparation method of the multi-block conductive binder provide a new way to manufacture multifunctional binders. A n-type multi-block polymer PPy- b -PB of poly(1-pyrenemethyl methacrylate) (PPy) and polybutadiene (PB) was designed to enhance the reversible deformation ability, flexibility, and adhesion length scale of the conductive binder PPy. With high initial coulombic efficiency of 77.9%, the PPy- b -PB/Si anode possesses high reversible capacity (2274 mAh g−1) and capacity retention (87.1%) at the rate of 0.2 C (0.84 A g−1) after 200 cycles. Image 1 • A novel multi-block binder was prepared by Condensation and RAFT polymerization. • The binder was used as conductive binder for Si anodes in Li-ion batteries. • Reversible deformation ability of the binder was improved with polybutadiene. • High capacity and cycling stability of Si anode was achieved by using the binder. [ABSTRACT FROM AUTHOR]

Abstract SiO x has emerged as an important alternative to silicon as the high capacity anode host to store lithium due to its smaller volume change upon lithiation. However, conventional synthesis methods generally require harsh reaction conditions, making its production in industrial scale much challenging. Herein, a safe, economical and scalable approach is developed for SiO x using highly abundant natural silica as starting material via a magnesio-mechanochemical reduction process induced by ball-milling. The as-prepared SiO x is intrinsically porous and comprised of mixed nano clusters of SiO 2 and Si. Upon lithiation, SiO 2 nano domains convert into lithium silicates and Li 2 O, which help to absorb Si volume expansion and participate in the formation of a stable solid electrolyte interface. Such synergistic effect leads to exceptional cycling stability up to 2000 cycles with 71.3% capacity retention under 4 A g−1. After blending with graphite, a high areal capacity of 2.64 mAh cm−2 demonstrates stable cycling of 89.7% retention over 200 cycles with an high initial Coulombic efficiency of 82.3%, implying the feasibility for practical applications. Structural and compositional characterizations reveal the involved chemistry and evolution mechanism of the formed solid electrolyte interface upon cycling, providing guidelines of designing future silicon-based materials for future Li-ion batteries. Graphical abstract Image 1 Highlights • Synthesis of nano SiO x from natural silica by facile ball milling. • Exceptional long-term cycling stability up to 2000 cycles was demonstrated. • Superb structural stability derived from intrinsic porosity and the grown stable SEI. • Blending with graphite exhibited application feasibility with high areal capacity. [ABSTRACT FROM AUTHOR]

A large-size, bipolar-stacked and high-safety solid-state lithium battery with integrated electrolyte and cathode is fabricated conveniently via solvent-free UV-cure. Firstly, a series of new solid polymer electrolytes are synthesized through UV-cure, and exhibit a maximum conductivity of 1.29 × 10 −4  S cm −1 (60 °C), a wide electrochemical window (0–5.1 V) and excellent compatibility with Li. Secondly, solid-state LiFePO 4 /Li cell with integrated electrolyte and electrode is fabricated and delivers a high capacity of 113.3 mAh g −1 after the 100 th cycle, and the capacity retention is 90.2%. The outstanding cell performance is ascribed to the integrated electrolyte/cathode design which is beneficial for the interfacial impedance decreasing. Finally, a 5 cm × 8 cm size battery with integrated electrolyte/cathode is assembled conveniently, and it presents the 80.55% retention of discharge capacity at the 200 th cycle and high-safety. It can be well work under the conditions of bending, cutting, on the fire and even after nail penetration. Remarkably, the bipolar-stacked battery is also fabricated, and the open circuit voltage is as high as 6.33 V. Consequently, this work develops a series of new solid polymer electrolytes and proposes an advanced cell construction design for solid-state lithium batteries which is very suitable for the large-scale preparation. [ABSTRACT FROM AUTHOR]

Carbon coated 50 nm Si NPs using alkali lignin (AL) or alkali lignin-derived azo polymer (AL-azo-NO 2 ) as the low cost carbon precursors were synthesized. The Si@C composites were facilely prepared by evaporating solvent THF of the Si NPs/carbon precursor dispersion solutions followed by carbonization in nitrogen. The resulting Si@C composites showed a vesical-like morphology with integrated carbon coating on Si NPs. When used as the anode materials for Li-ion batteries, the nitrogen-doped carbon coated Si NPs (Si@C-AL-azo-NO 2 ) stemmed from the use of AL-azo-NO 2 showed superior electrochemical performance. As the results, Si@C-AL-azo-NO 2 exhibited a high reversible specific capacity of 882 mAh/g at a current of 200 mA/g over 150 cycles and a high coulombic efficiency (99%), paving the way for promising application of lignin in high performance Si@C anode materials for Li-ion batteries. [ABSTRACT FROM AUTHOR]

Nano-sized fillers in a polymer matrix with good distribution can play a positive role in improving polymer electrolytes in the aspects of ionic conductivity, mechanical property and electrochemical performance of Li-ion cells. Herein, polyethylene oxide (PEO)/Li 3 PS 4 hybrid polymer electrolyte is prepared via a new in-situ approach. The ionic conductivities of the novel hybrid electrolytes with variable proportions are measured, and the optimal electrolyte of PEO-2%vol Li 3 PS 4 presents a considerable ionic conductivity of 8.01 × 10 −4  S cm −1 at 60 °C and an electrochemical window up to 5.1 V. The tests of DSC and EDXS reveal that the Li 3 PS 4 nanoparticles with better distribution, as active fillers scattering in the PEO, exhibit a positive effect on the transference of lithium ion and electrochemical interfacial stabilities. Finally, the assembled solid-state LiFePO 4 /Li battery presents a decent cycling performance (80.9% retention rate after 325 cycles at 60 °C) and excellent rate capacities with 153, 143, 139 and 127 mAh g −1 at the discharging rate of 0.1 C, 0.2 C, 0.5 C and 1 C at 60 °C. It is fully proved that it is an advanced strategy to preparing the new organic/inorganic hybrid electrolytes for lithium-ion batteries applications. [ABSTRACT FROM AUTHOR]

Sodium-ion batteries (SIBs) have been investigated as promising alternatives to lithium-ion batteries (LIBs) because of the rich sodium natural resource. Exploring suitable electrode materials is still a great challenge for the practical applications of SIBs. Herein, we demonstrate a novel three-dimensional porous carbon-coated graphene (3D PG@C) anode for SIBs using silica as the porous template combined with a subsequent polyaniline (PANI)-converted carbon coating. The synthesis process mainly consists of deposition of SiO 2 nanoparticles on graphene surface, in situ polymerization of aniline monomers and carbonization of PANI and etching of SiO 2 . The resultant 3D PG@C composite possesses high electrical conductivity, rapid ion insertion, sufficient active sites, short ionic diffusion distance and stable structural integrity for efficient Na-storage. As an anode material for SIBs, the 3D PG@C composite delivers excellent Na-storage performance, in terms of high initial discharge capacity (824 mAh g −1 at 50 mA g −1 ), large reversible capacity and long cyclability (323 mAh g −1 after 1000 cycles at 1000 mA g −1 ) and remarkable rate capability (207 mAh g −1 at 10000 mA g −1 ). The design strategy reported in this work would provide a promising approach toward high-stable and long-life carbonaceous anode materials for SIBs. [ABSTRACT FROM AUTHOR]

Sn-based materials have received particular attention as high capacity anodes for rechargeable lithium-ion batteries (LIBs). However, poor stability induced by a serve volume expansion during repeated cycling still remains great challenges in practical application. In this paper, well-dispersed Sn nanoparticles embedded in the porous N-doped graphene-like carbon network (Sn@PNGC) were simply fabricated via a one-step thermal reaction. Owing to the advantages of the unique porous N-doped graphene-like carbon network, the Sn@PNGC composite can not only avoid the direct contact between metallic Sn and electrolytes coupled with accommodating the aggregation and volume expansion of Sn nanoparticles, but also provide sufficient active sites for Li + insertion and favorable transport kinetics for electron transport. As a consequence, the as-prepared Sn@PNGC anode suggests remarkable electrochemical performance with enhanced capacity, improved stable ability and rate capability, thus delivering an initial discharge capacity of 1129 mAh g −1 and a high reversible capacity of 595 mAh g −1 after 100 cycles at 100 mA g −1 , along with an enhanced rate capacity of 437 mAh g −1 after 300 cycles at 500 mA g −1 . The facile approach demonstrates great potential for the low-cost and scalable fabrication of advanced Sn-based anode materials for LIBs. [ABSTRACT FROM AUTHOR]

Tin oxide (SnO 2 ) is regarded as a promising anode material for both lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) due to its large theoretical capacity. However, poor electrical conductivity and the weak cyclability resulted from dramatic volume expansion upon cycling process still hinder its practical application. Herein, we report a facile two-step hydrothermal route to encapsulate core–shell structured carbon nanotube (CNT)@SnO 2 composite in a graphene coating with novel three-dimensional (3D) porous framework architecture (CNT@SnO 2 @G) as anode for both LIBs and SIBs. The resultant CNT@SnO 2 @G electrode suggests outstanding lithium and sodium storage performance with large specific capacity, remarkable cycling stability and excellent rate capability. For LIBs, it delivers a high initial discharge capacity of 1400 mAh g −1 at 100 mA g −1 , improved reversible capacity of 947 mAh g −1 after 100 cycles at 100 mA g −1 , and enhanced rate capability of 281 mAh g −1 at 3000 mA g −1 . In addition, sodium storage testing suggests that a high discharge capacity of 323 mAh g −1 after 100 cycles at 25 mA g −1 was achieved. The present unique structural design associated with the remarkable lithium and sodium storage performance ensures CNT@SnO 2 @G as an advanced anode material for rechargeable LIBs and SIBs. [ABSTRACT FROM AUTHOR]

Garnet-based solid-state lithium (Li) metal batteries are regarded as one of the most promising high-energy-density and high-safety batteries because of the broad electrochemical stability window and high Li ion conductivity of garnet electrolytes, as well as their excellent chemical stability against Li metal. However, during the practical batteries cycling, it is found that Li dendrites grow in the interior of garnet, especially in the grain boundary, thus leading to the short circuit of the working batteries, which seriously hinders the application of garnet-based Li metal batteries. In this review, we summarize the Li dendrites growth mechanism, characterization techniques, and the interfacial issue of garnet-based solid-state Li metal batteries. Meanwhile, the strategies for regulating Li dendrites growth are also analyzed. In addition, the further perspective and some suggestions are proposed to develop garnet-based solid-state Li metal batteries. This review tends to show fresh views on the understanding of Li dendrites growth mechanism in garnet electrolytes and the rational design of interfacial layer for regulating dendrites and manufacturing the batteries when pairing with Li metal anode. [Display omitted] • The lithium dendrites growth mechanism in garnet is systematically analyzed. • The strategies for regulating lithium dendrites growth are also be summarized. • High electronic conductivity of garnet induces dendritic lithium growth. • Lithium dendrites grow mainly along the interior, especially in the grain boundary. • Building interfacial layer on garnet effectively regulates lithium dendrites growth. [ABSTRACT FROM AUTHOR]

• Flexible solid-state cells are developed with an in situ integration strategy. • A 20-µm-thick hybrid polymer/ceramic/ionic liquid electrolyte is prepared. • Stable interfaces are built, keeping intimate contact and reducing resistance. • The Li 4 Ti 5 O 12 /LiNi 0.8 Co 0.1 Mn 0.1 O 2 cell exhibits long cycling life at 30 °C. • The use of Si-based anode achieves 489.6 Wh kg−1 energy density at material's level. Flexible solid-state batteries (FSSBs) are indispensable energy storage devices to fulfil the energy and safety requirements for future flexible applications. The bottlenecks of FSSBs are how to realize high energy density with competent ionic conductivity for room-temperature (RT) flexible applications. Here, the first fabrication of RT FSSB with high energy density is reported, which is realized by in situ integration of a 20-µm-thick hybrid polymer/ceramic/ionic liquid solid-state electrolyte (SSE) between the high energy combination of anode/cathode electrodes. The in situ electrode/electrolyte interfacial integration strategy provides an ultrathin SSE layer, ultralow resistance and superior flexibility, and the SSE guarantees both high ionic conductivity and good compatibility with high-energy cathode LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811). The fabricated Li 4 Ti 5 O 12 /NCM811 FSSB delivers super-low resistance approaching conventional liquid cells and excellent cycling stability up to 600 cycles at RT. The extension of anode to SiO x @graphite leads to a high theoretical energy density of 489.6 Wh kg−1 at material's level, times higher than current options. In addition, the RT FSSB shows great flexibility, indicating a high performance application in future flexible electronics. [ABSTRACT FROM AUTHOR]

[Display omitted] • Robust chemical combination and space confinement effect in MGS-M nanocomposites. • Highly oxidized Mn 3 O 4 and increased Li+ active sites improve the specific capacity. • High pseudocapacitance contribution favors the rate capacity and cycle life. • Amorphous phase provides more Li+ active sites, diffusion paths and voids. Mn 3 O 4 -based materials have been broadly investigated as anode materials for lithium- ion batteries (LIBs) due to their high energy densities, affordable cost, environmental benignity, etc. However, the wide voltage hysteresis due to inferior electronic conductivity and serious volume expansion during lithiation/delithiation seriously restricted their practical applications. In this work, Mn 3 O 4 /graphene sheet (MGS) nanocomposites were prepared by a solution reaction assisted calcination method, which led to superior electrochemical performance for LIBs and presented both high reversible capacity and excellent cyclic stability (1199.5 mAh g−1 after 600 cycles and 995.3 mAh g−1 after 1000 cycles at a current density of 500 mA g−1). The superior cyclic stability could be attributed to the amorphization effect of Mn 3 O 4 and strong coupling interaction between Mn 3 O 4 and graphene sheets. On one hand, the highly oxidized Mn 3 O 4 and increasing Li+ active sites during extended cycles are beneficial to achieve high specific capacity. Meanwhile, the strong coupling effect, fast pseudocapacitive reaction and amorphous phase effect help provide numerous voids, which effectively alleviate volume expansion and enable excellent cyclic stability, enriching their great opportunities for LIBs anode materials with narrow voltage hysteresis and long cycle life. [ABSTRACT FROM AUTHOR]

[Display omitted] • An amorphous nanostructured organic anode is developed through chelation strategy. • The organic anode delivers a high specific capacity of 1283 mAh/g at 0.1 A/g. • The organic anode has an excellent rate performance. • The organic anode achieves an outstanding capacity retention at high mass loading. The rising pursuit for green rechargeable energy storage devices desires novel electrode materials with cost-effective, environmental-friendly properties besides high electrochemical performance, boosting the rapid development of organic electrodes. However, the organic electrode materials in most reports can hardly be used in the real applications due to relatively poor electrochemical performance. Herein, by utilizing a smart supramolecular self-assembly between metal ions and ligands, we facilely chelate the rhodizonic acid disodium salt (RA) using ferric ions and generate a novel organic anode material (RAFe) for the first time. The strong chelation interaction between ferric ions and rhodizonic acid changes its initial structure and characteristics, enabling the obtained organic RAFe compound with outstanding electrochemical performance as anode for lithium ion batteries (LIB), which includes high reversible capacity (1283 mAh/g at 0.1A/g), excellent rate capability, long cycling stability (0.5 A/g over 300 cycles with a capacity retention of 90.76%, i.e. 0.03% decay per cycle). Even at a high mass loading of 4.0 mg/cm2, this organic anode can still deliver a capacity over 1000 mAh/g with the specific area capacity of 4.09 mAh/cm2 at 0.2 A/g, and maintains it over 92.4% after 100 cycles. Apart from offering a promising organic anode material, this work also broadens the application of metal chelation interaction based supramolecular self-assembly in energy storage territory which will inspire the preparation of other high-performance organic materials for advanced LIBs. [ABSTRACT FROM AUTHOR]

Constructing a stable microstructure is highly crucial in promoting the practical applications of Si-based negative electrodes, addressing the issues of huge volume change and unstable solid electrolyte interface (SEI). Herein, an integrated electrode structure is developed based on micro-sized SiO x particles by bilayers coating of carbon and poly(3,4-ethylene dioxythiophene) (PEDOT) with carbon nanotube/Super P conductive network in-situ embedded (SiO x @C@P_CS). The as-prepared SiO x @C@P_CS negative electrode exhibits high Coulombic efficiency reaching 99.9% and capacity retentions of 86.7% (1019 mAh g−1) after 1000 cycles at 750 mA g−1 and 98.4% (973 mAh g−1) after 400 cycles at 1500 mA g−1 (with a commercial-level areal capacity of 2.57 mAh cm−2). The excellent long cycling capability is further evidenced both in half cell with ultrahigh areal capacity up to 11.75 mAh cm−2 at the mass loading of 8.66 mg cm−2 and Li[Ni 0.8 Co 0.1 Mn 0.1 O 2 (NCM811)||SiO x @C@P_CS full cell with commercial loading. The improved electrochemical performance is attributed to the synergistic effects of the bilayers. This study offers a facile solution to the challenges facing alloying-type negative electrode materials with huge volume changes by confining volume change, enhancing electric conductivity, and isolating the growth of SEI to promote their practical uses. Image 1 • An integrated electrode structure is developed based on micro-sized SiO x particles. • The inner layer is carbon for the bilayers coating of SiO x. • The outer layer is poly(3,4-ethylene dioxythiophene) with conductive network. • Superior electrochemical performance of the bilayers coated SiO x is achieved. [ABSTRACT FROM AUTHOR]

High-performance electrode materials with intelligent design hold the promise for the development of lithium ion batteries regarding high energy density and long cycling life. Herein, we report an artificial solid electrolyte interphase (SEI) modified porous SiO x anode (P-SiO x) prepared by a facile in-situ polymerization of tannin (PTN) under alkaline condition, forming an elastic polymer layer surrounding P-SiO x particles. The as-prepared P-SiO x @PTN composite demonstrates higher initial Coulombic efficiency (ICE) and stronger mechanical property than the P-SiO x. Consequently, the outer elastic and electric buffer layer ensures the composite showing a high reversible capacity of 1616 mAh g−1 at 0.1 C and exceptional long-term cycling performance. Moreover, when coupled with LiNi 0.8 Mn 0.1 Co 0.1 O 2 cathode, high reversible capacity (123 mAh g−1) and good capacity retention (83 mAh g−1 after 300 cycles) at 0.5 C are achieved. This facile method constructing the artificial solid electrolyte interphase with enhanced mechanical and electrochemical properties by the in-situ PTN is of great promise for Si-based anode materials. Unlabelled Image • An artificial solid electrolyte interphase modified SiO x composite is prepared. • The artificial layer ensures the structure stability of the SiO x composite. • The as-prepared SiO x composite exhibits excellent electrochemical performance. [ABSTRACT FROM AUTHOR]

• Non-flammable electrolyte with TMP and F-EPE improves the safety of SIB. • TMP/F-EPE electrolyte stabilizes the interface of NFM cathode during all processes. • The cycling life of NFM/HC pouch cell increases by using TMP/F-EPE electrolyte. Despite their beneficial effect on battery safety, non-flammable electrolytes often have an adverse side effect on the electrochemical performance of lithium and sodium ion batteries due to their poor compatibility with the electrodes. In this paper, we report a new non-flammable electrolyte consisting of trimethyl phosphate (TMP) and 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (F-EPE) as non-flammable solvents and fluoroethylene carbonate (FEC) as additive with different concentration of Na salts, and a EC-DEC-FEC electrolyte was also prepared as baseline electrolyte. The flammability and non-flammability of the prepared electrolytes was tested. It is shown that the prepared electrolyte not only increases the capacity (129.9 vs. 122.5 mAh g−1 of baseline electrolyte) of NaNi 1/3 Fe 1/3 Mn 1/3 O 2 (NFM) cathode but also stabilizes the cyclability (70.8% retention after 500 cycles) of NFM/HC (HC: hard carbon) pouch cells. The dissolution of pristine NaNi 1/3 Fe 1/3 Mn 1/3 O 2 cathode material in different solvents and electrolytes, and the XPS patterns of the cycled NFM cathode in the prepared electrolytes were also studied to understand the capacity fading mechanism. These results indicate that this new non-flammable electrolyte holds great potential for application in rechargeable sodium-ion batteries. [ABSTRACT FROM AUTHOR]