Sulfide-based all-solid-state lithium batteries (ASSLBs) have attracted unprecedented attention in the past decade due to their excellent safety performance and high energy storage density. However, the sulfide solid-state electrolytes (SSEs) as the core component of ASSLBs have a certain stiffness, which inevitably leads to the formation of pores and cracks during the production process. In addition, although sulfide SSEs have high ionic conductivity, the electrolytes are unstable to lithium metal and have non-negligible electronic conductivity, which severely limits their practical applications. Herein, a grain boundary electronic insulation strategy through in situ polymer encapsulation is proposed for this purpose. A polymer layer with insulating properties is applied to the surface of the Li_5.5PS_4.5Cl_1.5 (LPSC) electrolyte particles by simple ball milling. In this way, we can not only achieve a dense electrolyte pellet but also improve the stability of the Li metal anode and reduce the electronic conductivity of LPSC. This strategy of electronic isolation of the grain boundaries enables stable deposition/stripping of the modified electrolyte for more than 2000 h at a current density of 0.5 mA cm^–1 in a symmetrical Li/Li cell. With this strategy, a full cell with Li(Ni_0.8Co_0.1Mn_0.1)O₂ (NCM811) as the cathode shows high performance including high specific capacity, improved high-rate capability, and long-term stability. Therefore, this study presents a new strategy to achieve high-performance sulfide SSEs.

中文翻译：

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通过原位聚合物封装实现晶界电子绝缘策略的无枝晶Li5.5PS4.5Cl1.5基全固态锂电池


硫化物基全固态锂电池（ASSLB）由于其优异的安全性能和高能量存储密度，在过去十年中受到了前所未有的关注。然而，作为ASSLBs的核心部件的硫化物固态电解质（SSE）具有一定的刚度，这不可避免地导致在生产过程中形成孔隙和裂纹。此外，虽然硫化物SSE具有高离子电导率，但电解质对锂金属不稳定且具有不可忽略的电子电导率，这严重限制了其实际应用。为此，本文提出了通过原位聚合物封装的晶界电子绝缘策略。通过简单的球磨，将具有绝缘性能的聚合物层涂覆到Li _5.5 PS _4.5 Cl _1.5 (LPSC)电解质颗粒的表面。这样，我们不仅可以获得致密的电解质颗粒，还可以提高锂金属负极的稳定性并降低LPSC的电子电导率。这种晶界电子隔离策略使得改性电解质能够在对称 Li/Li 电池中以 0.5 mA cm ^–1 的电流密度稳定沉积/剥离超过 2000 小时。通过这种策略，以 Li(Ni _0.8 Co _0.1 Mn _0.1 )O ₂ (NCM811) 为阴极的全电池如图所示高性能包括高比容量、改进的高倍率能力和长期稳定性。因此，本研究提出了一种实现高性能硫化物SSE的新策略。