Chen, HsiHsiChenLiu, Hao-WenHao-WenLiuLu, Yu-ChengYu-ChengLuYu, Pei-JanePei-JaneYuLiao, Cheng-HungCheng-HungLiaoWang, Chun-ChiehChun-ChiehWangChan, Ting-ShanTing-ShanChanSheu, Hwo-ShuennHwo-ShuennSheuChang, Po-YaPo-YaChangChen, Jeng-LungJeng-LungChenHaw, Shu-ChihShu-ChihHawYin, Gung-ChianGung-ChianYinSong, Yen-FangYen-FangSongPao, Chih-WenChih-WenPaoNAE-LIH WU2025-07-302025-07-302025-09-0113858947https://www.scopus.com/record/display.uri?eid=2-s2.0-105009423006&origin=resultslisthttps://scholars.lib.ntu.edu.tw/handle/123456789/730824LiNiO2 (LNO) offers the highest specific capacity among Ni-rich cathodes at a reduced cost. To address its safety concerns and poor cycle life in liquid-electrolyte (LE) applications, we investigate the performance of a free-standing composite cathode membrane integrating LNO with Li3InCl6 (LIC) solid electrolyte (SE) in an all-solid-state Li-metal battery (ASSLMB) operating under a high-capacity (>200 mAh g−1) and low-stack pressure (∼2 MPa) mode- a more commercially relevant but underexplored operating condition. The LNO composite cathode exhibited significantly enhanced cycle stability compared to LNO in the reference LE cells. We analyzed the dynamics of the LNO ASSLMB using systematic synchrotron operando X-ray characterizations, including absorption, diffraction, and microscopy. Our findings reveal that, while the LNO-LIC interfaces remain strongly bonded upon cycling, thanks to a solvent-mediated synthesis process, LNO crystal-structural disordering, particle cracking, and LNO-LIC interfacial side reactions persist as the three key challenges for cycle stability. The structural-disordering induced fading is predominant and highly dependent on the cut-off voltage above 4.1 V, while the severity of cracking and LNO-LIC interfacial side reactions are less dependent. The results underscore LIC's high-voltage stability, establishing 4.1 V as a critical threshold for achieving long-term cycle stability of LNO in the ASSLMB. This study provides novel solutions and significant insights regarding the applications of LNO in halide-based ASSLMBs.falseAll-solid-state lithium-metal batteriesCycle lifeLi3InCl6LiNiO2Low-stack pressureSynchrotron characterizations[SDGs]SDG7journal article10.1016/j.cej.2025.1653142-s2.0-105009423006