Design Principles of Quinone Redox Systems for Advanced Sulfide Solid-State Organic Lithium Metal Batteries.

The emergence of solid-state battery technology presents a potential solution to the dissolution challenges of the high-capacity small molecule quinone redox systems. Among the various available solid-state electrolytes, the argyrodite-type Li 6 PS 5 Cl is regarded as one of the most promising system due to high room-temperature ionic conductivity and low-temperature processability. Nonetheless, the successful integration of Li 6 PS 5 Cl and quinone redox systems into solid-state organic lithium metal batteries remains elusive due to their inherent reactivity. Here, a library of quinone derivatives is selected as model electrode materials to ascertain the critical descriptors governing the (electro)chemical compatibility and subsequently the performances of Li 6 PS 5 Cl-based solid-state organic Li-metal cells. Compatibility is attained if the lowest unoccupied molecular orbital level of the quinone derivative is sufficiently higher than the highest occupied molecular orbital level of Li 6 PS 5 Cl. The energy difference is demonstrated to be critical in ensuring chemical compatibility during composite electrode preparation and enable high-efficiency operation of solid-state organic Li-metal cells. Considering these findings, a general principle is proposed for the selection of quinone derivatives to be integrated with Li 6 PS 5 Cl, and two solid-state organic Li-metal cells, based on 2,5-diamino-1,4-benzoquinone and 2,3,5,6-tetraamino-1,4-benzoquinone, are successfully developed and tested for the first time. Validating critical factors for the design of organic battery electrode materials is expected to pave the way for advancing the development of high-efficiency and long cycle life solid-state organic batteries based on sulfides electrolytes. This article is protected by copyright. All rights reserved.