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The reaction mechanism and kinetics of synthesis Li1.16(Ni0.25Mn0.75)0.84O2 were studied at different heating rates with the thermal analysis (TG-DTA) and non-isothermal kinetic analysis. The average activation energies were 167.40 kJ·mol−1 and 139.69 kJ·mol−1 between 200 and 450 °C (peak 2), and 450 and 560 °C (peak 3) as calculated by the Flynn-Wall-Ozawa and Kissinger methods. The reaction order, frequency factor, and kinetic equation of peak 2 and peak 3 were determined by the Kissinger method. Based on the results of the mechanism and dynamic study, the Li-rich and Mn-based cathode materials Li1.16(Ni0.25Mn0.75)0.84O2 were synthesized by an optimized two-step sintering process. The study results show that the materials show a layer structure with high crystallinity and superior electrochemical performance. Notably, the sample exhibits the discharge capacity of 225.4 mAhg−1, 92.7% of the initial discharge capacity after 300 cycles, accompanying with a high energy density retention of 140 Whkg−1.

Due to the theoretical ultrahigh energy density of the Li-O2 battery chemistry, it has been hailed as the ultimate battery technology. Yet, practical Li-O2 batteries usually need to be designed in a large-sized pattern to actualize a high specific energy density, and such batteries often cannot be cycled effectively. To understand the inherent reasons, we specially prepared large-sized (13 cm × 13 cm) Li-O2 model batteries with practical energy output (6.9 Ah and 667.4 Wh/kgcell) for investigations. By subregional and postmortem analysis, the cathode interface was found to have severe local inhomogeneity after discharge, which was highly associated with the electrolyte and O2 maldistribution. The quantitative results by X-ray photoelectron spectroscopy (XPS) evidenced that this local inhomogeneity can exacerbate the generation of lithium acetate during charge, where the locally higher ratio of unutilized carbon surface and less Li2O2 after discharge would result in increased lithium acetate formation for a subsequent local overcharge. Moreover, verification experiments proved that the byproduct lithium acetate, which had been of less concern, was recalcitrant and triggered much larger polarization compared with the commonly reported byproduct Li2CO3 during battery operations, further revealing the key limiting factors leading to the poor rechargeability of batteries by its accumulation at a pouch-type cell level.

Cathode interface instability is a significant obstacle for the practical application of sulfide-based all-solid-state lithium-ion batteries (ASSLIBs). However, the origin of cathode interface degradation is lack of comprehensive understanding. In this paper, X-ray characterizations combined with electrochemical analysis are adopted to investigate the underlying degradation mechanism at cathode interface. The results indicate that residual lithium compounds on the surface of Ni-rich LiNi0.8Mn0.1Co0.1O2 (NMC811) are the main reason that triggering the oxidation of sulfide solid-state electrolytes (SSEs), therefore inducing severe side-reactions at cathode interface and structural degradation of NMC811. The degradation of the cathode interface can be significantly suppressed when the cathode surface is cleaned. As a result, the surface cleaned NMC811 without coating demonstrates significantly improved electrochemical performance in both Li5.5PS4.5Cl1.5 (LPSCl) and Li10GeP2S12 (LGPS) based ASSLIBs, proving the universal application of this strategy.

The energy issue is an important issue affecting the development of countries worldwide. To solve the problem of resource depletion faced by fossil energy, to cope with global warming, and to achieve sustainable development, the development, utilization, and promotion of new energy sources have received universal attention. Halide solid electrolytes have a stable oxidation potential above 4 V, matching the LiCoO2 cathode material with considerable electrochemical performance. This review addresses the electrochemical performance and possible problems matching solid-state halide electrolytes with LiCoO2 and Ni-rich NCM. This paper concludes that halides have electrochemical stability and high ionic conductivity at high potentials matching LiCoO2 and Ni-rich NCM and good electrochemical properties. However, whether surface reactions exist when it is matched to a high nickel ternary material with a high surface base content, the evolution of the interface between the high nickel ternary material and the halide electrolyte during cycling and the factors affecting the performance of Ni-rich NCM in halide solid-state batteries need to be further investigated.

The development of high-performance sulfide electrolyte-based all-solid-state lithium-ion batteries (ASSLIBs) has been inhibited by problematic ionic transport and side reactions at the cathode interface, and their success is dependent on the functionalized interface upon charging and discharging. Despite recent progresses, it has proven challenging to design a favorable interface that can suppress the side reactions and enable smooth motion of Li+ ions. Herein, a favorable Zr-based cathode interface is elaborately manipulated by the atomic layer deposition (ALD) for sulfide-based ASSLIBs. Flexile control over the Li sub-cycle during the preparation process is demonstrated to be crucial for achieving a robust cathode interface with a desirable Li+ ionic conductivity. The ASSLIBs equipped with this functional interface exhibit excellent cycling stability and rate capability at room temperature (RT). Various electrochemical and spectroscopic characterizations reveal that the ionic conductive interface can significantly limit side reactions and induce a low polarization of the (de)intercalation toward cathode materials. The interfacial manipulation regarding ionic conductivity and structure realized by ALD provides a new strategy to achieve high-performance ASSLIBs.

Li–O2 battery is a promising rechargeable battery candidate due to its ultrahigh theoretical energy density. However, safety issues and poor cycling stability of Li–O2 batteries caused by the forma...

The separator is used to isolate the cathode and anode material, playing an important role in the safety of battery, which prevents internal short circuit of battery and provides lithium ions free flow channels. In this paper, based on the commercial ceramic-coated polyethylene (PE) separator (CPES), low-melting point PE microspheres were mixed in ceramic-coating to form the functionalized PE separator (FPES) for improving the safety tolerance of large scale lithium-ion batteries (LIBs). Compared to the CPES shutdown temperature of ~135 °C, the shutdown temperature of FPES significantly decreased to ~110 °C. Compared with 27 Ah pouch battery assembled by CPES, the FPES can effectively improve the tolerance of overcharge and internal short circuit without sacrificing the electrochemical performance. In addition, a novel internal short circuit of FPES protection mechanism model was proposed. Molten PE microspheres of FPES would flow along the edge of broken hole, reducing the contact probability between the cathode and anode, and ultimately increasing the resistance of internal short circuit by 41% compared to CPES. Therefore, the obtained results provide important implications for the development of safer separator and LIBs.

Understanding the relationship between structure, ionic conductivity, and synthesis is the key to the development of superionic conductors. Here, a series of Li3-3xM1+xCl6 (−0.14 < x ≤ 0.5, M = Tb, Dy, Ho, Y, Er, Tm) solid electrolytes with orthorhombic and trigonal structures are reported. The orthorhombic phase of Li–M–Cl shows an approximately one order of magnitude increase in ionic conductivities when compared to their trigonal phase. Using the Li–Ho–Cl components as an example, their structures, phase transition, ionic conductivity, and electrochemical stability are studied. Molecular dynamics simulations reveal the facile diffusion in the z-direction in the orthorhombic structure, rationalizing the improved ionic conductivities. All-solid-state batteries of NMC811/Li2.73Ho1.09Cl6/In demonstrate excellent electrochemical performance at both 25 and −10 °C. As relevant to the vast number of isostructural halide electrolytes, the present structure control strategy guides the design of halide superionic conductors.

All-solid-state lithium-ion batteries (ASSLIBs) are receiving significant attention owing to their improved safety and energy density over liquid counterparts. However, single-crystal cathodes have never been investigated in ASSLIBs. In this work, single-crystal Li(Ni0·5Mn0·3Co0.2)O2 (SC-NMC532) is used as the cathode material for ASSLIBs, which exhibits 6–14 times higher Li+ diffusion coefficient than polycrystalline Li(Ni0·5Mn0·3Co0.2)O2 (PC-NMC532). As a result, SC-NMC532 exhibits an initial specific capacity of 156.4 ​mAh.g−1 while PC-NMC532 shows an initial capacity of only 127.5 ​mAh.g−1. After 150 cycles, SC-NMC532 retains the capacity of 94.5 ​mAh.g−1. More impressively, under a high current density of 1.3 ​mA ​cm−2, SC-NMC532 exhibits a capacity of 82 ​mAh.g−1, much higher than that of PC-NMC532 (2.1 ​mAh.g−1). This work demonstrates that single-crystal NMC cathodes could enable both high power density and high energy density of ASSLIBs.

One of the primary obstacles that has inhibited the development of solid-state batteries is the lower conductivity of solid electrolytes compared to liquid electrolytes. Li6PS5Br is a promising solid electrolyte for solid-state batteries due to its high ionic conductivity and low cost. Herein, we enhance the lithium conductivity by replacing S with Br and systematically tailor the composition and synthesis parameters to optimize the conductivity. Li5.5PS4.5Br1.5 exhibits higher ionic conductivity and better lithium compatibility than the bare Li6PS5Br. Although lithium metal is chemically unstable with Li5.5PS4.5Br1.5, stable cycling behavior in lithium symmetrical cells with small overpotential and resistance after 2500 ​h are achieved. Both the bare NCM622 and LiNbO3-coated NCM622 shows long cycling life with Li5.5PS4.5Br1.5 electrolyte in combination with In or lithium metal anodes. The LiNbO3 layer can effectively improve the capacity and cycling behavior of the solid-state battery using different anodes. Moreover, the electrochemical performances of Li5.5PS4.5Br1.5-based solid-state batteries are influenced by the charge/discharge voltage windows.

Recently, halide solid-state electrolytes (SSEs) have been reported to exhibit high ionic conductivity and good compatibility with cathode materials. However, the air stability of halide-based elec...

Li–O2 batteries have attracted significant interest in the past decade owing to their superior high specific energy density in contrast to conventional lithium ion batteries. An 8.7-Ah Li–O2 pouch cell with 768.5 Wh kg−1 was fabricated and characterized in this investigation and the factors that influenced the electrochemical performance of the Li–O2 pouch cell were studied. In contrast to coin/Swagelok-type Li–O2 cells, it was demonstrated that the high-loading air electrode, pulverization of the Li anode, and the large-scale inhomogeneity of the large pouch cell are the major reasons for the failure of Li–O2 batteries with Ah capacities. In addition, safety tests of large Li–O2 pouch cells were conducted for the first time, including nail penetration, crushing, and thermal stability. It was indicated that a self-limiting mechanism is a key safety feature of these batteries, even when shorted. In this study, Li–O2 batteries were investigated in a new size and capacity-scale, which may provide useful insight into the development of practical pouch-type Li–O2 batteries.

All-solid-state lithium sulfur batteries (ASSLSBs) are considered promising candidates for next-generation energy-storage systems due to their enhanced safety and high theoretical energy density. However, usually both solid-state electrolyte (SSE) and conductive carbon need to be incorporated into the cathode composite to provide Li+/electron pathways, leading to the reduced energy density and inevitable SSE decomposition. Moreover, the real electrochemical behavior of S or Li2S cathodes can not be reflected due to the partially overlapped redox reaction of SSE. Herein, a series of unique P4S10+n cathodes for high-performance ASSLSBs that totally do not need any extra SSE additives are reported. Synchrotron-based X-ray absorption near edge structure coupled with other analyses confirmed that ionic conductive Li3PS4 together with Li4P2S6 components can be electrochemically self-generated during lithiation process and partially maintained to provide fast Li+ transport pathways within the cathode layer. This is further evidenced by a 30–43-fold higher reversible capacity for P4S10+n/C cathodes compared to a S/C cathode. Bulk-type ASSLSBs based on the P4S34/C cathode show a highly reversible capacity of 883 ​mAh g−1 and stable cycling performance over 180 cycles with a high active material content of 70 ​wt%. The present study provides a promising approach for generating ionic conductive components from the electrode itself to facilitate Li+ migration within electrodes in ASSLSBs.

All-solid-state lithium-ion batteries (ASSLIBs) are expected as safe and high-performance alternatives to replace the conventional liquid-based lithium-ion batteries. However, the incompatible interface between the most cathode materials and sulfide-based solid electrolytes is still challenging the stable delivery of electrochemical performance for ASSLIBs. Herein, a dual-functional Li3PO4 (LPO) modification is designed for Ni-rich layered oxide cathodes in sulfide-based ASSLIBs to realize the high performance. The modified cathode demonstrates a significantly improved initial capacity of 170.6 ​mAh g-1 at 0.1C, better rate capability, and reduced polarization compared to the bare cathode. More importantly, a stable long-term cycling is achieved with a low capacity degradation rate of 0.22 ​mAh g-1 per cycle for 300 cycles at 0.2C. The detailed surface chemical and structural evolutions are studied via X-ray absorption near edge spectroscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy. The results indicate that the LPO modification not only significantly suppresses the side-reactions with sulfide electrolyte but also helps to alleviate the deterioration of the microstructural cracks during the electrochemical reactions. This work provides an ideal and controllable interfacial design for realizing high performance sulfide-based ASSLIBs, which is readily applicable to other solid-state battery systems.

Solid polymer electrolytes (SPEs)-based all-solid-state lithium batteries (ASSLBs) with high-safety and high-performance have been regarded as promising next-generation energy storage devices. A fly in the ointment is that the cycling life is significantly limited by the Li dendrite growth. To tackle the Li dendrite issue, a selective Li deposition strategy is proposed, for the first time, to suppress Li dendrite formation via the rational design of a patterned Li anode. Through a facile and low-cost template-press method, the Li anode was divided into numerous square Li with deep grooves around 100 ​μm. Benefiting from the focused current density in the grooves, the Li preferentially deposits in the grooves instead of on the surface, thus suppressing the Li dendrite formation during the Li plating/stripping process. With this in mind, both cycling life of the assembled Li–Li symmetric cells and Li–LiFePO4 (LFP) full cells is prolonged for over 5 times. The Li–Li symmetric cells assembled with the patterned Li exhibit excellent cycling stability for 800/400 ​h ​at 0.1/0.2 ​mA ​cm−2. More importantly, the 3–4 ​mg ​cm−2 LFP-loaded patterned Li/PEO/LFP cell achieves high capacity retention of 91.3% within 100 cycles at 0.5C, while different degrees of short-circuits occurred for the bare Li/PEO/LFP cells.

The enabling of high energy density of all-solid-state lithium batteries (ASSLBs) requires the development of highly Li+-conductive solid-state electrolytes (SSEs) with good chemical and electrochemical stability. Recently, halide SSEs based on different material design principles have opened new opportunities for ASSLBs. Here, we discovered a series of LixScCl3+x SSEs (x = 2.5, 3, 3.5, and 4) based on the cubic close-packed anion sublattice with room-temperature ionic conductivities up to 3 × 10-3 S cm-1. Owing to the low eutectic temperature between LiCl and ScCl3, LixScCl3+x SSEs can be synthesized by a simple co-melting strategy. Preferred orientation is observed for all the samples. The influence of the value of x in LixScCl3+x on the structure and Li+ diffusivity were systematically explored. With increasing x value, higher Li+, lower vacancy concentration, and less blocking effects from Sc ions are achieved, enabling the ability to tune the Li+ migration. The electrochemical performance shows that Li3ScCl6 possesses a wide electrochemical window of 0.9-4.3 V vs Li+/Li, stable electrochemical plating/stripping of Li for over 2500 h, as well as good compatibility with LiCoO2. LiCoO2/Li3ScCl6/In ASSLB exhibits a reversible capacity of 104.5 mAh g-1 with good cycle life retention for 160 cycles. The observed changes in the ionic conductivity and tuning of the site occupations provide an additional approach toward the design of better SSEs.

Sulfide-based solid-state electrolytes (SSEs) are considered a key part in the realization of high-performance all solid-state lithium-ion batteries (ASSLIBs). However, the incompatibility between ...

All-solid-state Li metal batteries (ASSLMBs) have attracted significant attention because of their high energy density and improved safety. However, the poor stability at the Li anode/solid-state e...

Sulfide solid electrolytes have recently attracted significant interest for use in all-solid-state lithium batteries (ASSLBs) due to their high ionic conductivity. However, one of the main challeng...

A Li-rich layered oxide material of Li1.18Mn0.52Co0.15Ni0.15O2 with Li3PO4 as an outer modification layer and a spinel as an inner modification layer on the surface of primary particles was synthesized by a facile synchronous method. A series of physical characterization techniques indicate that Li3PO4 and the spinel simultaneously form not only on the surface but also in the bulk of the cathode material during the preparation process. Consequently, a stable protective layer and a highly conductive interlayer are fabricated by the formation of the Li3PO4 and spinel phase on the primary particle surface of the cathode material. The modified sample exhibits an improved initial coulombic efficiency of approximately 88.5%. Moreover, the capacity retention of the modified sample increases to 92% after 100 cycles at a rate of 0.2C from 2.0 to 4.8 V compared to that of the pristine sample (62.7%). Moreover, the modified sample also exhibits an excellent rate capability of 171.4 mA h g−1 at a 5C rate relative to the pristine sample (134.1 mA h g−1). Our facile modification approach combines the merits of the spinel phase and the Li3PO4 compound. Also, our approach can remarkably suppress the structural transformation from layered to spinel-like and decrease the loss of active materials by mitigating the formation of corrosion pits on the particles as well as enhancing the dynamic performance of Li+ diffusion of Li-rich layered oxides.

In electric vehicles (EVs), owing to the necessity of large amounts of energy and power, lithium-ion batteries need to be used in series and parallel configurations. However, the performance of the battery pack is lower than that of any single cell within the pack because of the inconsistency among the packed cells. Herein, the inconsistent voltages of unpacked cells due to varying capacities during discharge are analyzed to provide mechanical reason for inconsistency of battery pack. In terms of dispersion and symmetry, the statistical characteristics of voltage distribution are described using Weibull parameters and is investigated using a numerical analysis of the characteristic voltage curve. The numerical analysis results agree well with the experimental and statistical ones, which confirms that voltage inconsistency originating from manufacturing processes is primarily related with capacity inconsistency and the features of the voltage curves. Furthermore, this numerical approach can provide not only significant theoretical insight into the formation and evaluation of voltage inconsistency; but also practical guidance for controlling the quality of cell production and state estimation for the battery pack due to its low computational cost.

All-solid-state lithium batteries (ASSLBs) are promising energy storage devices for application in electric transportation and large-scale energy storage systems. Polyethylene oxide (PEO)-based solid polymer electrolytes (SPEs) are attractive solid-state electrolytes for ASSLBs due to their high ionic conductivity, light weight, and low cost. However, the low electrochemical oxidation potential window of PEO seriously restricts its implementation with high voltage cathodes for high-energy-density ASSLBs. Effective interfacial engineering between high voltage cathodes and SPEs can be a solution. Most of the reported conventional cathode protection approaches have been focused on building coating layers on active material particles, which, however, can be insufficient because the conductive carbon is able to accelerate the decomposition of SPEs. In this work, atomic layer deposition (ALD) coating on the electrode instead of active material particles realizes a unique method to protect the cathode/SPE interface. As a successful example, a thin ALD-derived lithium tantalate coating on the high-voltage LiCoO2 electrode demonstrated good compatibility with PEO-based SPEs, significantly enhancing the cycling performance of the ASSLBs. The inner mechanism is attributed to the fact that the protection of the conductive carbon/SPE interface helps reduce the electrochemical oxidation of PEO-based SPEs. This work shall give new insights for the interfacial engineering of high voltage cathodes and solid polymer electrolytes.

Due to higher energy density, high-voltage all-solid-state lithium batteries (ASSLBs) have attracted increasing attention. However, they require solid-state electrolytes (SSEs) with wide electrochemical stability windows (ESW, typically >4.2 V) and high-stability against the Li anode. Nevertheless, poly(ethylene oxide) (PEO), the most widely used solid polymer electrolyte (SPE), can’t tolerate a high-voltage over 4 V. Whether the main chain (–C–O–C–) or the terminal hydroxide group (–OH) is the limiting factor for the narrow ESW remains unknown. Herein, poly(ethylene glycol) (PEG) and poly(ethylene glycol)dimethyl ether (PEGDME) with different terminal groups are selected to answer this question. The results show that the reactive terminal –OH group is the limiting factor towards applicability against high voltage and the Li anode. Replacing –OH with more stable –OCH3 can significantly extend the ESW from 4.05 to 4.3 V, while improving the Li-anode compatibility as well (Li–Li symmetric cells stably run for 2500 h at 0.2 mA cm−2). Its practical application is further proved by developing PEGDME-based ASSLB pouch cells. The 0.53 mA cm−2 Li–LiFePO4 and 0.47 mA h cm−2 Li–LiNi0.5Mn0.3Co0.2O2 cells demonstrated high capacity retention of 97% and 90% after 210 cycles and 110 cycles, respectively. This work offers a new strategy for PEO-based high-voltage ASSLB development by changing the unstable terminal groups.

The development of new materials and the understanding of the microstructure formation of electrodes have become increasingly important for improving Li-ion battery performance. In this study, we investigate the effect of solid content on the rheological properties of and the microstructures in the cathode slurry prepared from Ni-rich materials. With long-chain structures, PVDF molecules can change their configurations when they come into contact with the solid particles in slurries, and their bridging function can change with the solid content in the slurry. Below the optimum content, particle sedimentation easily takes place. Above the optimum content, excessive yield stress is created in the slurry, and this stress is not conducive to homogeneous distribution of the components. The rheological properties of the slurries vary greatly under different solid contents. We investigated the uniformity and stability of the slurry prepared from Ni-rich materials and found that the most suitable solid content of the slurry lies in the range from 63.9% to 66.3%. Our work might assist in the production of high-performance Li-ion batteries that are made using an electrode slurry.

A practical strategy to enhance the electrochemical performance of Li-rich and Mn-based Li1.38Ni0.25Mn0.75O2.38 has been introduced. Its micromorphology and microstructure are controlled during the preparation process. Powder X-ray diffraction (XRD) and Raman spectroscopy reveal that the as-obtained materials can be indexed as the α-NaFeO2 phase. Field emission scanning electron microscopy (FESEM) analyses demonstrate that the as-fabricated Li1.38Ni0.25Mn0.75O2.38 materials consist of 10–15 μm spherical secondary particles aggregating with spherical nanoscale primary particles, and the primary particle size and stacking faults can be controlled by altering the calcination temperature. The electrochemical measurements show that Li1.38Ni0.25Mn0.75O2.38 with nanoscale primary particles with the diameter of 100–200 nm and an appropriate amount of stacking faults obtained at 850 °C exhibits higher capacity and superior cycling performance, delivering an initial discharge capacity of 265.7 mA h g−1 at 0.1C, 243.1 mA h g−1 at 0.2C, 222 mA h g−1 at 1.0C and 169 mA h g−1 at 2.0C, accompanied with a capacity retention of 89.3% and 78.6% after 300 cycles and 500 cycles at 1.0C, respectively. Meanwhile, the XPS, EIS and TEM results of the electrodes indicate that the capacity fading in the first 50 cycles may be caused by interfacial side-reactions between electrode and electrolyte.

Silicon nanowires of high purity and regular morphology are of prime importance to ensure high specific capacities of lithium-ion batteries and reproducible electrode assembly process. Using nickel formate as a metal catalyst precursor, straight silicon nanowires (65–150 nm in diameter) were directly prepared by electrolysis from the Ni/SiO2 porous pellets with 0.8 wt% nickel content in molten CaCl2 at 900 °C. Benefiting from their straight appearance and high purity, the silicon nanowires therefore offered an initial coulombic efficiency of 90.53% and specific capacity of 3377 mAh/g. In addition, the silicon nanowire/carbon composite exhibited excellent cycle performance, retaining 90.38% of the initial capacity after 100 cycles. Whilst further study on the charge storage performance is still ongoing, these preliminary results demonstrate that nickel formate is an efficient and effective metal catalyst precursor for catalytic preparation of high purity straight silicon nanowires via the molten salt electrolysis, which is suitable for large-scale production.

All-solid-state batteries are expected to be promising next-generation energy storage systems with increased energy density compared to the state-of-the-art Li-ion batteries. Nonetheless, the electrochemical performances of the all-solid-state batteries are currently limited by the high interfacial resistance between active electrode materials and solid-state electrolytes. In particular, elemental interdiffusion and the formation of interlayers with low ionic conductivity are known to restrict the battery performance. Herein, we apply a nondestructive variable-energy hard X-ray photoemission spectroscopy to detect the elemental chemical states at the interface between the cathode and the solid-state electrolyte, in comparison to the widely used angle-resolved (variable-angle) X-ray photoemission spectroscopy/X-ray absorption spectroscopy methods. The accuracy of variable-energy hard X-ray photoemission spectroscopy is also verified with a focused ion beam and high-resolution transmission electron microscopy. We also show the significant suppression of interdiffusion by building an artificial layer via atomic layer deposition at this interface.

Silicon nanowires are a kind of promising negative electrode material for lithium-ion batteries. However, the existing production technologies can hardly meet the demands of silicon nanowires in qu...

Poly(ethylene oxide) (PEO) based solid polymer electrolytes (SPEs) have been regarded as promising electrolytes for next-generation all-solid-state lithium batteries (ASSLBs). However, they have achieved limited cycling stability due to their inability to suppress Li dendrite growth. Herein, a self-healing electrostatic shield (SHES) is proposed to force uniform lithium deposition by introducing 0.05 M Cs+. At this situation, the Cs+ shows a lower reduction potential compared to the Li+ reduction potential (1.7 M). During lithium deposition, the Cs+ forms a positively charged electrostatic shield around the initial Li tips, which forces further deposition of lithium to adjacent regions of the anode and results in a dendrite-free Li deposition. With this in mind, the Li–Li symmetric cells can operate for 1000 and 500 h at current densities of 0.1 and 0.2 mA cm−2, respectively, which are 10 times longer than Cs+-free PEO electrolyte. Moreover, the Li/PEO-Cs+/LiFePO4 (LFP) cell achieves high capacity retention of 90% within 100 cycles at 0.5C and retains a high capacity of 113 mAh g−1 at 0.8C, while short-circuits are observed for the Li/PEO/LFP cell, even at 0.2C. This strategy will generate substantial interest and shed light on the development of other dendrite-free SPEs and ASSLBs systems.

Due to the theoretical ultrahigh energy density of the Li-O

All-solid-state lithium-ion batteries (SSLIBs) are promising candidates to meet the requirement of electric vehicles due to the intrinsic safety characteristics and high theoretical energy density....

All-solid-state lithium batteries (ASSLBs) assembled with solid polymer electrolytes (SPEs) have been regarded as promising next-generation rechargeable batteries with improved safety and high energy densities. However, the Li dendrites and poor Li+ transport greatly inhibit their practical applications when coupled with relatively high loading cathodes. Herein, we combine a glass fiber (GF)-reinforced composite polymer electrolyte based on poly(ethylene oxide) (labeled as PEO@GF) to suppress Li dendrite growth with a freeze-casted vertically-aligned (VL) electrode to facilitate Li+ transport in the high loading cathode. Benefiting from the enhanced mechanical strength and uniformed Li deposition enabled by the implanted GF, the Li–Li symmetric cells exhibit significantly improved cycling stability up to 2000 h (0.2 mA cm−2, 0.2 mAh cm-2) and 1000 h (0.42 mA cm−2, 0.4 mAh cm−2), which are over one order of magnitude longer than those of the pure PEO electrolyte. Furthermore, VL-LiFePO4 (LFP) cathode divides the thick electrode into numerous vertically-aligned “thin electrodes”, which significantly decreases the Li+ transport distance and enables the Li | PEO@GF | VL-LFP cell with a high LFP loading of 10.5 mg cm-2 to deliver a high areal capacity of 1.52 mAh cm−2. The rational structure design of both electrolyte and electrode offers an opportunity for developing high-performance ASSLBs with high active material loadings.

Safe, high-energy-density and long-life Li metal batteries (LMBs) are highly attractive as a power source. However, the development of LMBs encounters serious challenges due to the formation of Li dendrites and the leakage and flammability of organic liquid electrolytes. Herein, a novel nanowire-film-reinforced hybrid gel polymer electrolyte (HGPE) is developed. The interconnected porous nanowire film as the backbone not only strengthens the mechanical structure of GPEs but also ensures the continuity for Li+ conduction. The designed HGPE can simultaneously achieve the suppression of Li dendrites and high ionic conductivity (1.04 × 10−3 S cm−1). The films with controllable thicknesses offer the ability to prepare ultrathin HGPEs with great mechanical properties. With these merits, the Li metal symmetric cells exhibit significantly enhanced cycling stability for over 2100 h with low overpotential. The Li–O2 battery using the HGPE also delivers an ultralong cycle life of up to 494 cycles. The present study may open a new window for reinforcing GPEs and offer an opportunity for developing quasi-solid-state LMBs.

Li- and Mn-rich (LMR) layered materials with large specific capacities are one of the most promising cathodes for high-energy Li-ion batteries. However, the oxygen redox reaction induced by the activation of the Li2MnO3 component leads to lattice oxygen release and transition metal migration from the surface, which result in a large irreversible capacity loss, poor rate capability and inferior cycle stability compared with other cathodes. In this study, an integrated surface modification of combining a coating and chemical treatment is proposed to achieve modified LMR cathode materials with graphene wrapping layers and surface spinel phases. The graphene layer promotes electron transfer, and the spinel phase interlayer accelerates Li+ diffusion. Simultaneously, the combination of the two components increases the structural stability of LMR materials. As a result, the surface-modified LMR cathode exhibits a high rate capability of 154.3 mA h g−1 at 5C and an excellent cycle stability with a capacity retention of 84.2% after 200 cycles at 1C. In addition, the structural evolution of the surface-modified LMR cathode material was studied by in situ synchrotron X-ray diffraction analysis during the charge–discharge process, which illustrates that the surface modification has a significant effect on mitigating oxygen release by enhancing the surface structural stability.

Most inorganic solid-state electrolytes (SSEs) suffer from incompatibility with oxide cathode materials and instability in ambient air, presenting major barriers for their application in high performance all-solid-state batteries (ASSLBs). Herein, we report a rationally designed halide-based Li3InCl6 SSE with a high ionic conductivity of 1.49 × 10−3 S cm−1 (25 °C). The Li3InCl6 SSE is stable towards oxide cathode materials (e.g., LiCoO2) without any interfacial treatment. By applying the Li3InCl6 SSEs, significantly enhanced electrochemical performances are achieved in terms of capacity and durability. Experimental investigations reveal that the Li3InCl6 can avoid side reactions between the SSEs and the oxide cathode materials and thus effectively improve the Li+ migration across the interface. Moreover, Li3InCl6 is highly stable in ambient air and possesses good ionic conductivity retention after a reheating process, further making it an attractive electrolyte for next-generation ASSLBs.

The Li metal anode is an ideal candidate for next-generation batteries due to its ultra-high specific capacity (3860 mAh g−1) and low electrochemical potential (−3.040 V vs. standard hydrogen electrode). However, the large volume fluctuations, side reactions, and dendrite growth are serious problems that need to be solved before Li metal batteries (LMBs) can be commercialized. Herein, we develop a lithiophilic 3D Cu nanowire (3D CuNW) host that can enable molten Li infusion into the structure. Interestingly, the 3D host undergoes a structural transformation upon contact with molten Li and forms Cu-Li alloy crystallites on the surface, leading to the development of an ultra-high performance Li metal anode (3D Li@CuLi). The symmetrical cell performance of the 3D Li@CuLi electrode is found to be among the best reported for carbonate-based electrolytes and can achieve greater than 200 cycles at an ultra-high current density of 10 mA cm−2. Furthermore, full cells coupled with LiFePO4 cathodes show excellent cycling stability at a C-rate of 2 C for over 400 cycles with negligible capacity fade. This work provides a scalable and highly effective approach towards the fabrication of high performance 3D hosts with pre-stored Li metal for next-generation battery systems.

Safe and high-energy-density lithium rechargeable batteries are urgently required for vehicle electrification and grid energy storage. All-solid-state lithium metal batteries (ASSLMBs) are regarded as a good choice to meet these stringent requirements. However, interfacial instability between Li metal and solid-state sulfide electrolytes (SEs) and lithium dendrite formation are main challenges to be overcome. In this work, molecular layer deposition (MLD) is employed for the first time to develop an inorganic-organic hybrid interlayer (alucone) at the interface between the Li metal and SEs. It is found that the alucone layer can serve as an artificial solid electrolyte interphase (SEI). As a result, interfacial reactions between Li and SEs are significantly suppressed by intrinsically blocking electron transfer at the interface. In addition, lithium dendrites are also suppressed. Coupled with a LiCoO2 cathode, ASSLMBs with 30 MLD cycles of alucone on Li metal exhibit a high initial capacity of 120 mAh g−1 and can retain a capacity of 60 mAh g−1 after 150 cycles. This work exemplifies the use of MLD to stabilize the interface between SEs and Li metal for ASSLMBs.

Nickel-rich layered oxide and graphite–SiOx are regarded as promising electrode materials for high energy density lithium ion cells. It is significant to illustrate the degradation mechanism related to the aging process of nickel-rich layered oxide cathode and graphite–SiOx anode in full cell. In this study, the as-prepared pouch cell with LiNi0.88Co0.09Al0.03O2 as cathode material and graphite–SiOx as anode material has been proved with three aging stages according to the capacity retention changes in behavior. The aging process of the pouch cell is studied by non-destructive electrochemical methods. And then the pouch cells at different aging stages are disassembled and the cell components are studied by electrochemical characterizations for reassembled electrodes and physico-chemical analysis techniques. In the result, the cathode degradation is slight and as a minor factor for the degradation of the whole cell, and the anode deterioration is worse and as the main factor for the degradation of the whole cell. The organic and inorganic composition changes of the solid electrolyte interphase (SEI) induce the aging behavior differences of the three stages, and the reversible lithium loss, electrochemical polarization and active material shedding are mainly responsible for the three stages, respectively.

Understanding the relationship between structure, ionic conductivity, and synthesis is the key to the development of solid electrolytes for all-solid-state Lithium batteries. Here, we investigate chloride solid electrolytes with compositions Li3 − 3xM1+xCl6 (-0.14 x ≤ 0.5, M = Tb, Dy, Ho, Y, Er, Tm). When x > 0.04, a trigonal to orthorhombic phase transition occurs in the isostructural Li-Dy-Cl, Li-Ho-Cl, Li-Y-Cl, Li-Er-Cl and Li-Tm-Cl solid electrolytes. The new orthorhombic phase shows a four-fold increase in ionic conductivity up to 1.3×10− 3 S cm− 1 at room temperature for Li2.73Ho1.09Cl6 (x = 0.09) when compared to the trigonal Li3HoCl6. For isostructural Li-Dy-Cl, Li-Y-Cl, Li-Er-Cl and Li-Tm-Cl solid electrolytes, about one order of magnitude increase in ionic conductivities are observed for the orthorhombic structure compared to the trigonal structure. Using the Li-Ho-Cl components as an example, detailed studies of its structure, phase transition, ionic conductivity, air stability and electrochemical stability have been made. Molecular dynamics simulations based on density functional theory reveal that the different cations arrangement in the orthorhombic structure leads to a higher lithium diffusivity as compared to the trigonal structure, rationalizing the improved ionic conductivities of the new Li-M-Cl electrolytes. All-solid-state batteries of In/Li2.73Ho1.09Cl6/NMC811 demonstrate excellent electrochemical performance at both room temperature and − 10°C. As relevant to the vast number of isostructural halide electrolytes, the present structure control strategy provides guidance for the design of novel halide superionic conductors.