Son, Jun Pyo Park, Juhyoun Kim, Hae-Yong Kim, Jae-Seung Song, Yong Bae Kim, Changhoon Kim, Donghyeok Kim, Jong Seok Lee, Junwoo Ko, Sunho Jung, Soon-Jae Choi, Seungwoo Ahn, Docheon Chae, Keun Hwa Kwon, Gihan Wierzbicki, Dominik Du, Yonghua Lee, Hyun-Wook Seo, Dong-Hwa Nam, Kyung-Wan Jung, Yoon Seok 2025-11-21T02:06:46Z 2025-11-21T02:06:46Z 2025-11-11 2025-11 2058-7546 https://pubs.kist.re.kr/handle/201004/153588 Advances in battery technology have been impeded by the voltage constraints of electrolytes. Here we present a high-energy all-solid-state battery design featuring >5 V operation and an ultrahigh areal capacity of 35.3 mAh cm−2; these attributes were enabled by a highly conductive and ultrahigh-voltage stable fluoride solid electrolyte, LiCl–4Li2TiF6 (1.7 × 10−5 S cm−1 at 30 °C). LiCl–4Li2TiF6 shields high-voltage spinel oxide cathodes, achieving 106 mAh g−1 at 2C with 75.2% retention over 500 cycles for LiNi0.5Mn1.5O4, sharply contrasting with the conventional LiNbO3 counterpart, which decomposes and fails to prevent detrimental interfacial degradation. The efficacy of LiCl–4Li2TiF6 is validated across various systems, including LiCoMnO4, LiFe0.5Mn1.5O4 and pouch-type LiNi0.5Mn1.5O4||Li (or Ag–C) all-solid-state batteries, and further demonstrated by operability down to 2.3 V with 258 mAh g−1 and ultrathick 1.8-mm electrodes. This shielding layer with >5 V stability introduces a transformative design paradigm by revisiting the previously forbidden high-voltage cathodes. English NATURE PUBLISHING GROUP Five-volt-class high-capacity all-solid-state lithium batteries Article 10.1038/s41560-025-01865-y 1 Nature Energy, v.10, no.11, pp.1334 - 1346 Nature Energy 10 11 1334 1346 N scie scopus 001587396500001 2-s2.0-105017874803 Energy & Fuels Materials Science, Multidisciplinary Energy & Fuels Materials Science Article RAY-ABSORPTION SPECTROSCOPY SUPERIONIC CONDUCTOR CATHODE MATERIAL SPINEL STABILITY