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To offset the intermittent nature, renewable energy sources must be paired with energy storage systems (ESS) to cater to the demand for clean energy solutions. The performance characteristics requirements of these ESS are application‐specific, say batteries are characterized by their high energy capacity while supercapacitors offer greater power density. Currently, the research concentration in this domain is on improving the performance parameters of proven energy storage chemistries. Two‐dimensional (2D) materials characterized by high specific surface area, and tunable physical and electrical properties are explored extensively to enhance ESS performance. This review comprehends the progress made by two typical 2D materials, Graphene and Molybdenum disulfide, to enhance the energy/ power capacity, and life span of a few chosen rechargeable storage chemistries, lithium‐ion, lithium‐sulfur batteries, supercapacitors, and flow batteries. Further the review presents the current state of ESS, the challenges identified so far which restrict their capacity and life span, and the solutions employed to date. Finally, the challenges associated with these solutions are critically analyzed to suggest future directions and research perspectives in this domain. [ABSTRACT FROM AUTHOR]

Silicon material plays a vital role in contemporary technology-related fields, including electronics and the photovoltaics. There is a growing demand for exploring new silicon structures with potential applications, and numerous metastable structures have been reported. In this study, we present the prediction of a novel stable sp 3 hybridized silicon allotrope using particle swarm optimization global structure search. The predicted Si allotrope is a semiconductor with an indirect band gap of approximately 0.21 eV. It possesses three Si basis atoms in the unit cell, and we named it Si3. Interestingly, when subjected to strain, it undergoes a transition from a semiconductive state to a metallic state. Furthermore, moderate tensile strain enhances the interactions between silicon and lithium atoms, suggesting its potential for Li-ion batteries. Additionally, Si3 exhibits exceptional sunlight absorption across a wide range of wavelengths, with a significantly higher light absorption intensity than cubic diamond silicon. These findings have important implications for photovoltaic applications. [ABSTRACT FROM AUTHOR]

Li-ion batteries are currently considered promising energy storage devices for the future. However, the use of liquid electrolytes poses certain challenges, including lithium dendrite penetration and flammable liquid leakage. Encouragingly, solid electrolytes endowed with high stability and safety appear to be a potential solution to these problems. Among them, ionic liquids (ILs) packed in metal organic frameworks (MOFs), known as ILs@MOFs, have emerged as a hybrid solid-state material that possesses high conductivity, low flammability, and strong mechanical stability. ILs@MOFs plays a crucial role in forming a continuous interfacial conduction network, as well as providing internal ion conduction pathways through the ionic liquid. Hence, ILs@MOFs can not only act as a suitable ionic conduct main body, but also be used as an active filler in composite polymer electrolytes (CPEs) to meet the demand for higher conductivity and lower cost. This review focuses on the characteristic properties and the ion transport mechanism behind ILs@MOFs, highlighting the main problems of its applications. Moreover, this review presents an introduction of the advantages and applications of Ils@MOFs as fillers and the improvement directions are also discussed. In the conclusion, the challenges and suggestions for the future improvement of ILs@MOFs hybrid electrolytes are also prospected. Overall, this review demonstrates the application potential of ILs@MOFs as a hybrid electrolyte material in energy storage systems. [ABSTRACT FROM AUTHOR]

A magnetically induced self-assembled graphene nanoribbons (GNRs) method is reported to synthesize MFe2O4/GNRs (M = Co,Ni). It is found that MFe2O4 compounds not only locate on the surface of GNRs but anchor on the interlayers of GNRs in the diameter of less than 5 nm as well. The in situ growth of MFe2O4 and magnetic aggregation at the joints of GNRs act as crosslinking agents to solder GNRs to build a nest structure. Additionally, combining GNRs with MFe2O4 helps to improve the magnetism of the MFe2O4. As an anode material for Li+ ion batteries, MFe2O4/GNRs can provide high reversible capacity and cyclic stability (1432 mAh g−1 for CoFe2O4/GNRs and 1058 mAh g−1 for NiFe2O4 at 0.1 A g−1 over 80 cycles). [ABSTRACT FROM AUTHOR]

Li-ion batteries are currently considered promising energy storage devices for the future. However, the use of liquid electrolytes poses certain challenges, including lithium dendrite penetration and flammable liquid leakage. Encouragingly, solid electrolytes endowed with high stability and safety appear to be a potential solution to these problems. Among them, ionic liquids (ILs) packed in metal organic frameworks (MOFs), known as ILs@MOFs, have emerged as a hybrid solid-state material that possesses high conductivity, low flammability, and strong mechanical stability. ILs@MOFs plays a crucial role in forming a continuous interfacial conduction network, as well as providing internal ion conduction pathways through the ionic liquid. Hence, ILs@MOFs can not only act as a suitable ionic conduct main body, but also be used as an active filler in composite polymer electrolytes (CPEs) to meet the demand for higher conductivity and lower cost. This review focuses on the characteristic properties and the ion transport mechanism behind ILs@MOFs, highlighting the main problems of its applications. Moreover, this review presents an introduction of the advantages and applications of Ils@MOFs as fillers and the improvement directions are also discussed. In the conclusion, the challenges and suggestions for the future improvement of ILs@MOFs hybrid electrolytes are also prospected. Overall, this review demonstrates the application potential of ILs@MOFs as a hybrid electrolyte material in energy storage systems.

A magnetically induced self-assembled graphene nanoribbons (GNRs) method is reported to synthesize MFe2O4/GNRs (M = Co,Ni). It is found that MFe2O4 compounds not only locate on the surface of GNRs but anchor on the interlayers of GNRs in the diameter of less than 5 nm as well. The in situ growth of MFe2O4 and magnetic aggregation at the joints of GNRs act as crosslinking agents to solder GNRs to build a nest structure. Additionally, combining GNRs with MFe2O4 helps to improve the magnetism of the MFe2O4. As an anode material for Li+ ion batteries, MFe2O4/GNRs can provide high reversible capacity and cyclic stability (1432 mAh g−1 for CoFe2O4/GNRs and 1058 mAh g−1 for NiFe2O4 at 0.1 A g−1 over 80 cycles).

Preparation of Li7.06La3Y0.06Zr1.94O12 (Y-LLZ) solid electrolyte by the co-precipitation method is studied for the first time. The hydroxy-based co-precipitate would be formed from nitrate salts of Li, La, Zr, and Y. The co-precipitate is decomposed and La2Zr2O7 is formed at < 600 °C. High conductive cubic garnet phase is formed around 700 °C. This is consistent with previous studies. Well-sintered Y-LLZ pellet with large grains is obtained after sintering at 1000 °C for 6 h. The Li ion conductivity is also increased with sintering temperature, and the highest total conductivity is 4.9 × 10−4 S cm−1. This value is comparable to previous studies even though sintering temperature in this study is 100 ~ 200 °C lower than the previous Y-LLZ studies. Prepared Y-LLZ is a pure ionic conductor, and its electrochemical window is > 8.5 V vs. Li/Li+. Y-LLZ solid electrolyte can be prepared, and the sintering temperature of Y-LLZ can be lowered by the co-precipitation method. [ABSTRACT FROM AUTHOR]

This paper reports that the fully-discharged graphite-fluoride Li primary battery (GF/Li battery) can be regenerated as a hybrid capacitor with a higher energy density than the electric double layer capacitor (EDLC) using an activated carbon electrode. The graphite-fluoride (GF) positive electrode of the GF/Li battery is electrochemically defluorinated during the fully-discharged process to be converted to a nanocomposite consisting of carbon and LiF particles. The nanocomposite as the discharge product behaves as a capacitor-like electrode, so the fully-discharged GF/Li battery can be stably charged/discharged as a hybrid capacitor with the capacitor-type electrode (defluorinated GF electrode) and the battery-type negative electrode (Li metal). This hybrid capacitor, i.e., “graphite-fluoride Li capacitor (GF/Li capacitor)”, exhibited the maximum volumetric energy density of 52 Wh L−1 (at the power density of 71 W L−1), which is higher than that of the EDLC and comparable to that of the Li-ion capacitor. In this paper, the improvement of the cyclability by using the graphite/Li bilayer negative electrode and the charge-discharge mechanism are also discussed for the GF/Li capacitor.

Accurate capacity degradation path estimation of lithium-ion batteries plays a crucial role in ensuring the safety and reliability of electric vehicles. In recent years, the evolution of the status of health (SOH) prediction with machine learning techniques has become a research hotspot because of its powerful computing power and robustness. Thus, this study employes the sparse gaussian process regression (SGPR) data-driven approach with multi-features extracted from the battery cycling processes to project the potential degradation patterns of the lithium-ion batteries. Firstly, a battery life test platform was built. The accelerated life aging tests of batteries at different temperatures (25 °C, or 60 °C) and different discharge rates (1C, or 2C) were conducted to establish the dataset for the multi-features extraction and training of the SGPR algorithm. Secondly, different battery characteristic features were extracted based on the battery cycle charge-discharge curves. Various order-reduction treatments, i.e., the filter-based, embedding-based, and fusion-based selection algorithms, were performed to suppress the over-fitting and improve the estimate's accuracy. Finally, using the extracted features as inputs, SGPR models are constructed to estimate the degradation path of the battery. With the 50 % training data, the SGPR has a higher estimation accuracy than the regular GPR, and the average maximum absolute errors for the batteries are 2.80 %, 1.22 %, 3.57 %, and 1.83 %, respectively. • A fusion-based feature selection method is proposed to determine optimal features. • SGPR with fusion-based feature engineering algorithm can realize a low MAE level between 1.22% and 3.57 %. • Verification of the SOH prediction method under multiple working conditions. [ABSTRACT FROM AUTHOR]

We present a computational approach for identifying the important descriptors of the ionic conductivities of lithium solid electrolytes. Our approach discriminates the factors of both bulk and grain boundary conductivities, which have been rarely reported. The effects of the interrelated structural (e.g. grain size, phase), material (e.g. Li ratio), chemical (e.g. electronegativity, polarizability) and experimental (e.g. sintering temperature, synthesis method) properties on the bulk and grain boundary conductivities are investigated via machine learning. The data are trained using the bulk and grain boundary conductivities of Li solid conductors at room temperature. The important descriptors are elucidated by their feature importance and predictive performances, as determined by a nonlinear XGBoost algorithm: (i) the experimental descriptors of sintering conditions are significant for both bulk and grain boundary, (ii) the material descriptors of Li site occupancy and Li ratio are the prior descriptors for bulk, (iii) the density and unit cell volume are the prior structural descriptors while the polarizability and electronegativity are the prior chemical descriptors for grain boundary, (iv) the grain size provides physical insights such as the thermodynamic condition and should be considered for determining grain boundary conductance in solid polycrystalline ionic conductors.

• A composite film of PPC and Li 3 N is designed to protect Li anode. • The composite film avoids electrolyte/lithium contact and reduces side reactions. • The composite film exhibits excellent ionic conductivity and stability. • Excellent rate capability and high-temperature storage performance are achieved. • Evolution mechanisms of SEI and CEI are systematically analyzed. Though lithium primary battery has been widely used, high temperature and long-term storage still possibly cause its failure because of the active lithium anode, which continuously reacts with electrolyte, forms an unstable solid electrolyte interface and leads to the degradation of battery performance. In this work, a novel organic-inorganic composite protecting film composed of well-dispersed inorganic lithium nitride (Li 3 N) among poly (propylene carbonate) (PPC) organic matrix is controllably fabricated on the Li anode by spin coating, to enhance interfacial compatibility and stability. The composite film exhibits superior ionic conductivity of 3.57 × 10−4 S cm−1, and the Li-CF x battery with composite film delivers an excellent specific discharge capacity of 940 mAh g−1 at 0.1 C, and excellent rate capacity of 492 mAh g−1 even at 8 C. After storage at room temperature and 55 °C for 60 days, the battery can still release high specific capacities of 867 and 536 mAh g−1. With the assistance of composite film, a stable Li 3 N/LiF-rich SEI is formed on the Li anode and LiF-rich CEI is generated on the CF x cathode, ensuring long-term and high-temperature storage stability of Li-CF x battery. This study demonstrates a facile organic/inorganic composite film protecting strategy to achieve high-performance lithium battery. [ABSTRACT FROM AUTHOR]

We present a computational approach for identifying the important descriptors of the ionic conductivities of lithium solid electrolytes. Our approach discriminates the factors of both bulk and grain boundary conductivities, which have been rarely reported. The effects of the interrelated structural (e.g. grain size, phase), material (e.g. Li ratio), chemical (e.g. electronegativity, polarizability) and experimental (e.g. sintering temperature, synthesis method) properties on the bulk and grain boundary conductivities are investigated via machine learning. The data are trained using the bulk and grain boundary conductivities of Li solid conductors at room temperature. The important descriptors are elucidated by their feature importance and predictive performances, as determined by a nonlinear XGBoost algorithm: (i) the experimental descriptors of sintering conditions are significant for both bulk and grain boundary, (ii) the material descriptors of Li site occupancy and Li ratio are the prior descriptors for bulk, (iii) the density and unit cell volume are the prior structural descriptors while the polarizability and electronegativity are the prior chemical descriptors for grain boundary, (iv) the grain size provides physical insights such as the thermodynamic condition and should be considered for determining grain boundary conductance in solid polycrystalline ionic conductors. [ABSTRACT FROM AUTHOR]

Electrolytes with high Li+ transference number and good electrochemical stability are urgently needed for high-energy-density Li battery. In this paper, we present newly synthesized ionic liquid (IL)-based polymer electrolyte using polymer poly(ethylene oxide) (PEO), salt lithium bis(fluorosulfonly)imide (LiFSI), and IL 1-butyl-3-methylpyridinium bis(trifluoromethylsulfonyl)imide (BMPyTFSI) by solution cast technique. They show high Li+ transference number and good electrochemical and thermal stability. Also, nickel-rich layered cathode material LiNi0.90Co0.05Al0.05O2 (NCA) with good electrochemical performance for lithium secondary battery is successfully synthesized by Co-precipitation method. Using the optimized polymer electrolyte and NCA cathode, Li cell is prepared which shows initial discharge capacity of ~ 137 mAh g−1 at 0.1 C-rate and good Coulombic efficiency ~96.0% upto 125 cycles. [ABSTRACT FROM AUTHOR]

Due to the mechanism with which solid polymer electrolytes use to conduct ions, these materials are generally more suitable for high‐temperature applications where the ionic conductivity is sufficient and where liquid electrolytes show insufficient stability. To enable high‐temperature cycling of polymer electrolytes, the mechanical stability has to be improved. Herein, we report successful long‐term cycling of a solid polyester‐polycarbonate – poly(ϵ‐caprolactone‐co‐trimethylene carbonate) (poly(CL‐co‐TMC)) – electrolyte cross‐linked through the addition of multifunctional acrylates and the use of UV‐irradiation, allowing stable cycling of cells for more than 100 cycles at 80 °C, with good rate capabilities (0.2 mA cm−2) and Coulombic efficiencies exceeding 99 %. Both the mechanical properties and the ionic conductivity of the mechanically stabilized poly(CL‐co‐TMC) were investigated and optimized to reduce the frequency dependence of the moduli while still achieving an acceptable ionic conductivity at elevated temperature. These results indicate that the poly(CL‐co‐TMC) system can straight‐forwardly be modified to allow for higher‐temperature applications. [ABSTRACT FROM AUTHOR]

Nano-ZnMn2O4 and ZnMn2O4/MWCNT/graphene composites were prepared by solgel and ball-milling methods. The functional properties of the prepared samples were studied by applying various techniques. X-ray diffraction (XRD) Rietveld analysis indicated a single-phase ZnMn2O4 with a partially inverse spinel nanostructure (average size ≈ 7 nm), confirmed by TEM graphs, which revealed the morphology and particle nanosize distribution in samples. The samples were further characterized by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy (XPS). The Gaussian fitting of Zn 2p and Mn 2p narrow XPS spectrum confirmed the cation distribution obtained from XRD Rietveld analysis. The galvanostatic cycling of the pure ZnMn2O4 electrode exhibited higher initial discharge capacity (~ 1978 mAh g−1) when cycled at 100 mA g−1 versus Li/Li+. Meanwhile, the cyclic voltammetry tests evidenced the enhanced Li-ion diffusion during the oxidation and reduction processes. The assembled ZnMn2O4/MWCNT/G cell delivered about 190 mAh g−1 of specific discharge capacity over 100 cycles with 65% capacity retention. [ABSTRACT FROM AUTHOR]

Lithium is the most attractive anode material for high-energy density rechargeable batteries, but its cycling is plagued by morphological irreversibility and dendrite growth that arise in part from its heterogeneous "native" solid electrolyte interphase (SEI). Enriching the SEI with lithium fluoride (LiF) has recently gained popularity to improve Li cyclability. However, the intrinsic function of LiF--whether chemical, mechanical, or kinetic in nature--remains unknown. Herein, we investigated the stability of LiF in model LiF-enriched SEIs that are either artificially preformed or derived from fluorinated electrolytes, and thus, the effect of the LiF source on Li electrode behavior. We discovered that the mechanical integrity of LiF is easily compromised during plating, making it intrinsically unable to protect Li. The ensuing in situ repair of the interface by electrolyte, either regenerating LiF or forming an extra elastomeric "outer layer," is identified as the more critical determinant of Li electrode performance. Our findings present an updated and dynamic picture of the LiF-enriched SEI and demonstrate the need to carefully consider the combined role of ionic and electrolyte-derived layers in future design strategies. [ABSTRACT FROM AUTHOR]

Abstract We study the ion-conductive and electrochemical properties of concentrated poly (ethylene carbonate) (PEC)-based electrolytes with Li salt concentrations greater than 100 mol%. An end-capped PEC having acetate groups (PEC-Ac) was synthesized as a novel polymer matrix for improving the thermal stability and oxidative stability. A concentrated PEC-Ac electrolyte with 120 mol% of LiFSI had a good conductivity of approximately 10−6 S/cm at 40 °C with an excellent Li transference number (t +) of 0.8. Linear sweep voltammetry measurement for the PEC-Ac electrolyte indicates that the oxidation tolerance is more than 5 V, and is greater than that of the original PEC-based electrolyte. A battery test for the LiFePO 4 cell using the PEC-Ac electrolyte was conducted for the first time, finding good capacities ranging from 130 to 160 mAh/g and stable cyclability for more than 60 cycles. Graphical abstract Image 1 Highlights • A PEC having acetate end groups as a novel polymer electrolyte matrix. • The concentrated PEC electrolyte has excellent Li transference number, 0.8 • The end-capping improves thermal and oxidation tolerance of PEC electrolyte. • The end-capped PEC cell exhibits good discharge capacity and cyclability. [ABSTRACT FROM AUTHOR]

Antimony (Sb)-based materials are considered to be attractive for use in Li secondary battery anodes because of their high capacity. However, their huge volume change during Li insertion-extraction cycling limits their cycle performance. The Sb-active material can be combined with intercalation-based active materials to address these issues. In this study, spherical Sb core/Nb2O5 shell structured composite materials were synthesized through a simple solvothermal process and a carbon coating was simultaneously added during heat treatment using a naphthalene precursor. The resulting double-shelled materials were characterized with X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, and electron microscopy. The electrochemical test results showed that a reversible capacity of more than 450 mAh g−1 was retained after 100 cycles. This improved performance is ascribed to the double-shelled structure. The large volume change of the nano-sized Sb core material was alleviated by the double-shelled structure, which consisted of crystalline orthorhombic Nb2O5 and amorphous carbon. The shell materials also aided rapid charge transport.

Copper sulfide (Cu 7 S 4 ) nanoparticles were synthesized by adding ethanolic elemental sulfur solution to an aqueous solution containing Cu(II) precursor, branched polyethyleneimine (BPEI), and ascorbic acid. By varying the Cu(II) precursor used, we could control the morphology of the nanoparticles produced to be either quasi spherical (CuF 2 , Cu(NO 3 ) 2 , and CuSO 4 ) or vine like nanofibers (CuCl 2 and CuBr 2 ). By comparing experimental results and conducting calculations we found that selective adsorption of Br − and Cl − onto specific crystal facets and slowing of the reaction rate owing to formation of Cu(I)–anion–BPEI complexes explain the observed change in morphology from spherical particles to vine like nanofibers. We also found that the differences in morphology of Cu 7 S 4 nanoparticles affects the electrochemical performance of Li batteries including the nanoparticles as electrode materials. [ABSTRACT FROM AUTHOR]

The bulk of the scientific literature on Li-conducting solid (solvent-free) polymer electrolytes (SPEs) for applications such as Li-based batteries is focused on polyether-based materials, not least the archetypal poly(ethylene oxide) (PEO). A significant number of alternative polymer hosts have, however, been explored over the years, encompassing materials such as polycarbonates, polyesters, polynitriles, polyalcohols and polyamines. These display fundamentally different properties to those of polyethers, and might therefore be able to resolve the key issues restricting SPEs from realizing their full potential, for example in terms of ionic conductivity, chemical or electrochemical stability and temperature sensitivity. It is further interesting that many of these polymer materials complex Li ions less strongly than PEO and facilitate ion transport through different mechanisms than polyethers, which is likely critical for true advancement in the area. In this review, >30 years of research on these ‘alternative’ Li-ion-conducting SPE host materials are summarized and discussed in the perspective of their potential application in electrochemical devices, with a clear focus on Li batteries. Key challenges and strategies forward and beyond the current PEO-based paradigm are highlighted. [ABSTRACT FROM AUTHOR]

Micro carbon fibers (CFs) as a current collector were coated on sulfurized poly-acrylonitrile (SPAN) electrodes fabricated by using electrostatic flocking method. The alignment and flocking density of CFs and the electrochemical properties of SPAN electrodes were investigated with various flocking parameters of flocking distance, length of CF, and loading weight. A long flocking distance gave a sufficient space to rotate charged CFs and stand CFs on the surface of electrodes during flocking process. The flocking density was increased with a decrease of milling time and the increase of loading weight. The current collectors flocked with 12 h-milled carbon fibers (CFs) exhibited less weight than Al current collector. SPAN electrodes with CF current collector demonstrated better electrochemical performance than that with Al current collector. In particular, SPAN electrodes flocked with a loading weight of 0.3 g showed stable cycleability (76% of capacity retention until 100th cycle) and good rate capability (930 mAh/g_sulfur at 2.0 C-rate). [ABSTRACT FROM AUTHOR]

An electrochemically active nanostructured silver copper fluoride (SCF) perovskite, AgCuF 3 , was synthesized via a mechanochemical reaction between AgF and CuF 2 precursors. Phase composition and electrochemical properties of the SCF perovskites produced under various synthetic parameters were studied. The optimum SCF perovskite sample exhibited an appreciable electrochemical performance through the use of conductive carbon matrix in a primary lithium half cell. A high specific capacity of 270 mAh g −1 was achieved at a cutoff voltage of 2 V with 190 mAh g −1 above 3 V, leading to a total volumetric energy density of 3666 Wh L −1 at >3 V and 4848 Wh L −1 at >2 V. [ABSTRACT FROM AUTHOR]

In this article, we report a facile approach to enhance the electrochemical performance of Li-rich oxides with vulnerable phase stability. The Li-rich oxide nanoparticles were attached to the surface of graphene; the graphene surface acted as a matrix with high electronic conductivity that compensated for the low conductivity and enhanced the rate capability of the oxides. Our novel approach constitutes a direct assembly of two materials via electrostatic interaction, without a high-temperature heat treatment. The inevitable deterioration in phase integrity of previous composites between carbon and Li-rich oxides resulted from the reaction of oxygen in the structure with carbon during the heat-treatment process. However, our new method successfully attached Li-rich nanoparticles to the surface of graphene, without a phase change of the oxides. The resulting graphene/Li-rich oxide composites exhibited superior capacity and rate capability compared to their pristine Li-rich counterparts. [ABSTRACT FROM AUTHOR]

• A novel composite solid polymer electrolyte consisting of PVDF, Li 3/8 Sr 7/16 Zr 1/4 Ta 3/4 O 3 , and LiTFSI was investigated. • Li 3/8 Sr 7/16 Zr 1/4 Ta 3/4 O 3 active filler can improve the conductivity, thermal stability, electrochemical stability, and Li+ transference number of composite solid polymer electrolytes. • Composite solid polymer electrolyte consisting of 10 wt% Li 3/8 Sr 7/16 Zr 1/4 Ta 3/4 O 3 showed a low overpotential (∼64 mV) and excellent cycle stability in the cell of Li/Li. • Composite solid polymer electrolyte consisting of 10 wt% Li 3/8 Sr 7/16 Zr 1/4 Ta 3/4 O 3 was used in a LiFePO 4 /Li battery, and it exhibited a good capacity retention and a coulombic efficiency. Flexible composite solid polymer electrolytes (CSPEs) with good interfacial contact with electrodes and high stability against Li are promising candidate materials for quasi-solid-state Li battery. Herein, perovskite Li 3/8 Sr 7/16 Zr 1/4 Ta 3/4 O 3 (LSZT) with high conductivity (> 10−4 S·cm−1) and Li+ transference number (∼1) as the active filler was added to polyvinylidene fluoride (PVDF)+bis(trifluoromethanesulfonyl)imide (LiTFSI) polymer matrix to improve its performances. The X-ray diffraction pattern and Fourier transform infrared measurements showed that the structure of CSPEs comprised α, β, and γ mixed phases. The CSPE containing 10% LSZT powder (CSPE-10%) exhibited a high conductivity of 6.26 × 10−5 S·cm−1 at 20°C, thermal stability up to 353°C, electrochemical stability up to 4.61 V, and Li+ transference number of 0.54. The galvanostatic charge/discharge measurements using Li/CSPE-10%/Li cell showed that CSPE exhibited steady cycling at 0.05 mA·cm−2 for more than 300 h. LiFePO 4 /Li battery with CSPE-10% displays a high specific discharge capacity of 133.6 mAh·g−1 with 0.2 C rate at 25°C, along with good stable performance over 300 cycles. In this work, a new composite solid polymer electrolyte consisting of PVDF, Li 3/8 Sr 7/16 Zr 1/4 Ta 3/4 O 3 , and LiTFSI was investigated. Li 3/8 Sr 7/16 Zr 1/4 Ta 3/4 O 3 with a perovskite structure exhibits a high Li-ion conductivity of > 10−4 S·cm−1 and Li+ transference number of ∼1 at room temperature. Li 3/8 Sr 7/16 Zr 1/4 Ta 3/4 O 3 active filler added into the PVDF matrix can form a rapid Li+ conductive path in composite solid polymer electrolyte, which can enhance the ionic conductivity and Li+ transference number. Furthermore, the uniform distribution of Li 3/8 Sr 7/16 Zr 1/4 Ta 3/4 O 3 can immobilize TFSI− anion on the surface of active filler to inhibit space charge generation and further suppress the Li dendrite growth. Therefore, composite solid polymer electrolyte containing 10 wt% Li 3/8 Sr 7/16 Zr 1/4 Ta 3/4 O 3 exhibits a high conductivity of 6.26 × 10−5 S·cm−1 at 20°C, thermal stability up to 353°C, electrochemical stability up to 4.61 V, and Li+ transference number of 0.54. [Display omitted] [ABSTRACT FROM AUTHOR]

Li ion batteries and its accessories are now under increased focus of research due to enhanced energy storage and recycling requirements and the need for clean environments. In this context, observations on Li battery electrodes prepared using multi-wall carbon nanotubes (MWCNT) coated on stainless steel as observed by time of flight secondary ion mass spectrometry (TOF-SIMS) analysis and their relevance in understanding and improving the electrochemical properties of such battery systems are discussed. Porosity issues due to MWCNT, and accumulation of chemical residues with operational cycles were observed, their possible causes were also analyzed and discussed. Issues on change in electrode performance due to usage of tin oxide coatings on the MWCNT were also compared and analyzed. [ABSTRACT FROM AUTHOR]

Room temperature ionic liquids are considered as potential electrolytes for high performance and safe lithium batteries due to their very low vapor pressure and relatively wide electrochemical and thermal stability windows. Unlike organic electrolytes, ionic liquid electrolytes are molten salts at room temperature with dissociated cations and anions. These dissociated ions interfere with the transport of lithium ions in lithium battery. In this study, a mathematical model is developed for transport of ionic components to study the performance of ionic liquid based lithium batteries. The mathematical model is based on a univalent ternary electrolyte frequently encountered in ionic liquid electrolytes of lithium batteries. Owing to the very high concentration of components in ionic liquid, the transport of lithium ions is described by the mutual diffusion phenomena using Maxwell-Stefan diffusivities, which are obtained from atomistic simulation. The model is employed to study a lithium-ion battery where the electrolyte comprises ionic liquid with mppy + (N-methyl-N-propyl pyrrolidinium) cation and TFSI − (bis trifluoromethanesulfonyl imide) anion. For a moderate value of reaction rate constant, the electric performance results predicted by the model are in good agreement with experimental data. We also studied the effect of porosity and thickness of separator on the performance of lithium-ion battery using this model. Numerical results indicate that low rate of lithium ion transport causes lithium depleted zone in the porous cathode regions as the porosity decreases or the length of the separator increases. The lithium depleted region is responsible for lower specific capacity in lithium-ion cells. The model presented in this study can be used for design of optimal ionic liquid electrolytes for lithium-ion and lithium-air batteries. [ABSTRACT FROM AUTHOR]

Construction of advanced cathode materials is highly important for the development of high-performance lithium batteries. Herein, we report a facile polystyrene sphere template-assisted electro-deposition method for the fabrication of porous multilayer V 2 O 5 hollow sphere arrays on graphite paper substrates. The obtained V 2 O 5 arrays consist of interconnected hollow spheres with diameters of ∼500 nm as well as thin walls of 20–30 nm. All pores in the hollow sphere arrays are connected with each other and reach out in all directions forming 3D porous networks. As cathode of lithium batteries, the multilayer V 2 O 5 hollow sphere arrays show a high specific capacity of 293 mAh g −1 at 0.5C and good high-rate cycling stability with a specific capacity of 202 mAh g −1 at 5C after 300 cycles. The enhancement of the electrochemical properties is mainly due to the unique hollow sphere arrays architecture, which provides fast ion/electron transfer path and sufficient contact between active materials and electrolyte, and alleviates the structure degradation during the cycling process. [ABSTRACT FROM AUTHOR]

Fluorosulfonimide anions, including bis(fluorosulfonyl)imide ([(FSO 2 ) 2 N] − , FSI − ) and (fluorosulfonyl)(perfluoroalkanesulfonyl)imide ([(FSO 2 )( n −C m F 2 m +1 SO 2 )N] − , m = 1, 2, 4, 6, 8, etc.) anions, play an increasingly important role in electrolyte materials for rechargeable Li and Li-ion battery. Recent advances in the synthesis of fluorosulfonimides and their alkali metal salts are summarized. The main advances on the electrolytes of these anions for improving the electrochemical performances of rechargeable Li and Li-ion battery are reviewed, in terms of the types of electrolytes, including conventional liquid carbonate electrolytes, ionic liquid electrolytes, molten salt electrolytes, and solid polymer electrolytes. [ABSTRACT FROM AUTHOR]

Previous theoretical studies of C3B have suggested that boron-doped graphite is a promising H2-and Li-storage material, with large maximum capacities. These characteristics could lead to exciting applications as a lightweight H2-storage material for automotive engines and as an anode in anew generation of batteries. However, for these applications to be realized a synthetic route to bulk C3B must be developed. Here we show the thermolysis of a single-source precursor (1,3-(BBr2)2C6H4) to produce graphitic C3B, thus allowing the characteristics of this elusive material to be tested for the first time. C3B was found to be compositionally uniform but turbostratically disordered. Contrary to theoretical expectations, the H2-and Li-storage capacities are lower than anticipated, results that can partially be explained by the disordered nature of the material. This work suggests that to model the properties of graphitic materials more realistically, the possibility of disorder must be considered. [ABSTRACT FROM AUTHOR]