Mechanical damage of NCM811 (LiNi_0.8Co_0.1Mn_0.1O₂), severe interfacial side reactions, and physical contact failure of cathode and solid electrolyte (SE) are the main obstacles for it to achieve high-voltage stability in all-solid-state batteries (ASSLBs). The cathode morphology effects on the structural integrity are directly related to the electrochemical performance of ASSLBs. In this work, small-size single crystal NCM811 (S-SC) is synthesized for sulfide-based ASSLBs to solve mechanical damage and contact failure issues. In addition, the interfacial stability is improved by a Li₂O pre-lithiation strategy. Cross section polisher-scanning electron microscopy (CP-SEM) is applied to reveal the mechanical structure evolution behavior of NCM811 cathodes with different morphology. Electrochemical impedance spectroscopy (EIS), time of flight secondary ion mass spectrometry (TOF-SIMS), and X-ray photoelectron spectroscopy (XPS) technologies are applied to characterize the interfacial stability among cycling. As a result, with a high mass loading of 35.67 mg cm⁻² and high current density of 7.13 mA cm⁻², the Li₂O pre-lithiated S-SC (S-SC-PL) cathode delivers extraordinarily high-voltage stability of 100% after 500 cycles at 2.72–4.4 V and 100% after 200 cycles at 2.72–4.5 V in ASSLBs. This work provides an effective cathode morphological design strategy to improve high-voltage stability of Ni-rich layered cathodes for sulfide-based ASSLBs.

中文翻译：

---

硫化物基全固态锂电池小尺寸单晶富镍层状正极4.5 V高压稳定性

NCM811（LiNi _0.8 Co _0.1 Mn _0.1 O ₂）的机械损伤、严重的界面副反应以及正极与固体电解质（SE）的物理接触失效是其实现全固态高电压稳定性的主要障碍电池 (ASSLB)。阴极形貌对结构完整性的影响与ASSLBs的电化学性能直接相关。在这项工作中，合成了用于硫化物基ASSLB的小尺寸单晶NCM811（S-SC），以解决机械损伤和接触故障问题。此外，Li _{2还提高了界面稳定性。}O预锂化策略。应用截面抛光扫描电子显微镜（CP-SEM）揭示了不同形貌的NCM811阴极的机械结构演化行为。应用电化学阻抗谱（EIS）、飞行时间二次离子质谱（TOF-SIMS）和X射线光电子能谱（XPS）技术来表征循环过程中的界面稳定性。结果，Li _{2具有35.67 mg cm} ^-2的高质量负载和7.13 mA cm ^{-2的高电流密度。}O 预锂化 S-SC (S-SC-PL) 阴极在 ASSLB 中在 2.72–4.4 V 下循环 500 次后可提供 100% 的极高电压稳定性，在 2.72–4.5 V 下循环 200 次后可提供 100% 的极高电压稳定性。这项工作提供了一种有效的阴极形态设计策略，以提高硫化物基ASSLBs富镍层状阴极的高压稳定性。