Conventional lithium-ion batteries, with flammable organic liquid electrolytes, have seriouss afety problems, which greatly limit their application.A ll-solid-state batteries (ASSBs) have received extensive attention from large-scale energy-storage fields,s uch as electric vehicles (EVs) and intelligent powerg rids, due to their benefits in safety,e nergy density,a nd thermostability.A st he key component of ASSBs, solid electrolytes determine the properties of ASSBs. In past decades, various kinds of solid electrolytes, such as polymers and inorganic electrolytes, have been explored.Amongt hese candidates, organic-inorganic composite solid electrolytes (CSEs) that integrate the advantages of these two differente lectrolytes have been regarded as promising electrolytes for high-performanceA SSBs, and extensive studies have been carried out. Herein,r ecent progress in organic-inorganic CSEs is summarized in terms of the inorganic component, electrochemical performance, effects of the inorganicc eramic nanostructure, and ionic conducting mechanism. Finally,t he main challenges and perspectiveso fo rganic-inorganic CSEs are highlighted for future development.

Solid‐state lithium metal batteries (SLMBs) are attracting enormous attention due to their enhanced safety and high theoretical energy density. However, the alkali lithium with high reducibility can react with the solid‐state electrolytes resulting in the inferior cycle lifespan. Herein, inspired by the idea of interface design, the 1‐butyl‐1‐methylpyrrolidinium bis(trifluoromethanesulfonyl) imide as an initiator to generate an artificial protective layer in polymer electrolyte is selected. Time‐of‐flight secondary ion mass spectrometry and X‐ray photoelectron spectroscopy reveal the stable solid electrolyte interface (SEI) is in situ formed between the electrolyte/Li interface. Scanning electron microscopy (SEM) images demonstrate that the constructed SEI can promote homogeneous Li deposition. As a result, the Li/Li symmetrical cells enable stable cycle ultralong‐term for over 4500 h. Moreover, the as‐prepared LiFePO 4 /Li SLMBs exhibit an impressive ultra‐long cycle lifespan over 1300 cycles at 1 C, as well as 1600 cycles at 0.5 C with a capacity retention ratio over 80%. This work offers an effective strategy for the construction of the stable electrolyte/Li interface, paving the way for the rapid development of long lifespan SLMBs.

Composite solid-state electrolytes (CSEs) that integrate the merits of different components are considered to be promising candidate for the next-generation high-energy density lithium metal batteries. Herein, we have successfully designed...

To achieve superior solid-state lithium batteries, we have fabricated a flexible composite solid electrolyte (CSE) membrane composed of a poly(vinylidene fluoride) (PVDF) matrix, high-concentration lithium salt (LiTFSI), solvent (DMF), and ceramic filler Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 (LATP). A small quantity of polar solvent DMF can not only facilitate the dissociation of LiTFSI but also form lithium-rich complexes [Li(DMF) n TFSI] with Li + , which have the properties of ionic liquids and can improve ionic conductivity. Meanwhile, high-concentration LiTFSI provides a large number of free lithium ions, and TFSI − anions also aggregate to form ion clusters, which pass through the interconnecting network of the filler LATP to form a unique fast conduction channel. Thanks to the synergistic effect between the various components of the LATP-PVDF/Li CSE, the obtained CSE achieves a high ionic conductivity of 2.44 × 10 −4 S cm −1 (25 °C), an excellent electrochemical stability window of up to 4.8 V (vs Li + /Li), and desirable self-extinguishing ability. In addition, the CSE exhibits excellent lithium dendrite inhibition ability, which has been verified by periodic lithium stripping/plating tests for more than 3000 h. All of the assembled solid-state LiFePO 4 ||Li, LiCoO 2 ||Li, and LiNi 0.6 Co 0.2 Mn 0.2 O 2 ||Li cells exhibit distinguished rate performance and cycling stability at 30 °C. Furthermore, the LiFePO 4 ||Li solid-state pouch batteries also exhibit excellent flexibility and safety. This investigation demonstrates the importance of the synergistic strategy between the various components of the CSE and opens up ideas for the research and development of high-performance CSEs.

Solid polymer electrolytes (SPEs) with the advantages of high safety, low volatility, and the ability to suppress Li dendrites are highly desirable to be used in next generation high-safety and high-energy lithium-ion batteries. The exploration of SPEs with superior comprehensive properties has received extensive attention for high-performance all-solid-state batteries (ASSBs). Herein, a sandwich-like nanofibrous membrane-reinforced poly-caprolaclone diol and trimethyl phosphate (TMP) composite polymer electrolyte (CPE) has been designed by a facile "solvent-free" solution-casting method. Specifically, the flameretardant TMP is employed as a plasticizer, which can improve the ionic conductivity effectively. The as-prepared solid electrolyte exhibits superior comprehensive performance in terms of high ionic conductivity, wide electrochemical window, good compatibility with lithium metal, and superior thermal stability. Furthermore, the assembled Li//LiFePO 4 ASSBs with this solid CPE show outstanding cycling stability and high average discharge capacity at room temperature (30 °C). Undoubtedly, our study provides a new facile method and a qualified solid electrolyte material for next generation high-performance ASSBs.