Effective transport network driven by tortuosity gradient enables high-electrochem-active solid-state batteries. Issue 3 (28th November 2022)

• Record Type: Journal Article
• Authors: Liu, Qing-Song; An, Han-Wen; Wang, Xu-Feng; Kong, Fan-Peng; Sun, Ye-Cai; Gong, Yu-Xin; Lou, Shuai-Feng; Shi, Yi-Fan; Sun, Nan; Deng, Biao; Wang, Jian; Wang, Jia-Jun
• Is Part Of: National science review. Volume 10:Issue 3(2023)
• Publication Date: 2022-11-28
• Subjects: all-solid-state batteries -- thick electrodes -- lithiation/delithiation heterogeneity -- tortuosity gradient -- synchrotron techniques; Science -- Periodicals; 505
• DOI: 10.1093/nsr/nwac272
• Languages: English
• ISSNs: 2095-5138

Abstract

ABSTRACT: Simultaneously achieving high electrochemical activity and high loading for solid-state batteries has been hindered by slow ion transport within solid electrodes, in particular with an increase in electrode thickness. Ion transport governed by 'point-to-point' diffusion inside a solid-state electrode is challenging, but still remains elusive. Herein, synchronized electrochemical analysis using X-ray tomography and ptychography reveals new insights into the nature of slow ion transport in solid-state electrodes. Thickness-dependent delithiation kinetics are spatially probed to identify that low-delithiation kinetics originate from the high tortuous and slow longitudinal transport pathways. By fabricating a tortuosity-gradient electrode to create an effective ion-percolation network, the tortuosity-gradient electrode architecture promotes fast charge transport, migrates the heterogeneous solid-state reaction, enhances electrochemical activity and extends cycle life in thick solid-state electrodes. These findings establish effective transport pathways as key design principles for realizing the promise of solid-state high-loading cathodes. Abstract : A tortuosity-gradient thick electrode was developed to promote fast ion transport and mitigate the heterogeneous solid-state reaction, leading to excellent electrochemical performance for solid-state batteries.