闭式十氢十硼酸盐的制备及其固体电解质应用研究进展

全固态电池是一种具有前景的电化学储能装置，它可以克服传统有机液体电解质电池的多方面不足，包括电解质易泄漏、稳定性低、易燃和能量密度有限等问题。固态电解质是全固态电池的重要组成部分，开发具有高离子电导率和宽电化学稳定性窗口的固体电解质是研制高能量和高功率密度全固态电池的关键问题之一。硼氢化物基固态电解质作为一类新型电解质，因具有高离子电导率、高热稳定性和低密度等优势而受到了广泛关注。其中，闭式十氢十硼酸碱金属盐是代表性材料之一。自1959年B₁₀H₁₀^2-被发现以来，其合成方法、结构与应用开发都得到了广泛研究。近年来其在固态电解质方面的研究证实，M₂B₁₀H₁₀（M=Na、Li等）及其衍生物具有高离子电导率、高热稳定性和化学稳定性、高电位窗口等特性，是一类颇具前景的固态电解质材料。本文主要综述了B₁₀H₁₀^2-合成方法及其在固态电解质方面的应用研究进展，并对今后B₁₀H₁₀^2-作为固态电解质的发展方向提出了展望。

Progress in Preparation and Application in Solid Electrolyte of closo-Decahydrodecaborate

All-solid-state batteries (ASSBs) are commonly regarded as prospective electrochemical energy storage devices, which can overcome the drawbacks of conventional liquid electrolyte batteries, including electrolyte leakage, low stability, flammability, and limited energy density. In the research of ASSBs, developing solid electrolyte (SE) with high ionic conductivity and a wide electrochemical stability window is critical to the development of ASSBs with high energy and power density. Recently, hydroborate-based SEs have received extensive attention as they offer a comprehensive combination of super-ionic conductivity at high temperature, high thermal stability, and low density. Among these, one of the most promising materials is the alkali-metal salts of closo-decahydrodecaborate (B₁₀H₁₀^2-). Since B₁₀H₁₀^2- was first discovered in 1959, its synthetic methods and application have been widely studied. After years of research, mature methods for the preparation of the B₁₀H₁₀^2- compounds have been developed, which can satisfy the supply demands in the laboratory. As a multifunctional material, decahydrodecaborate has been intensively studied for several applications. In particular, as a promising candidate for SE, the sodium and lithium closo-decahydrodecaborates M₂B₁₀H₁₀ (M=Na, Li) have been proved to own excellent ionic conductivity as well as high thermal and chemical stability. To further improve the electrochemical performances of B₁₀H₁₀^2--based electrolytes at room temperature, many modification strategies have been explored and implemented, including halogen substitution, carboranate, mechanical ball milling, complex anion alloying, and dimerization. This review mainly describes the progress of preparation and application in the solid electrolyte of B₁₀H₁₀^2-, summarizes the modification strategies of better-performance B₁₀H₁₀^2- based SE, and also puts forward prospects for the future development of B₁₀H₁₀^2- as SE in ASSBs.