Direct Observation of Li‐Ion Transport Heterogeneity Induced by Nanoscale Phase Separation in Li‐rich Cathodes of Solid‐State Batteries. (23rd August 2022)

• Record Type: Journal Article
• Authors: Liu, Bowen; Hu, Naifang; Li, Chao; Ma, Jun; Zhang, Jianwei; Yang, Yuan; Sun, Deye; Yin, Bangxun; Cui, Guanglei
• Is Part Of: Angewandte Chemie. Volume 134:Number 40(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-08-23
• Subjects: All-Solid-State Batteries -- DPC-STEM -- Electrochemistry -- Li-Ion Transport -- Li-Rich Layered Oxides; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.202209626
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: Li‐rich layered oxide (LLO) cathode materials with high specific capacities could significantly enhance the energy density of all‐solid‐state lithium batteries (ASSLBs). However, the specific practical capacities of LLO materials in ASSLBs are extremely low due to poor initial activation. Here, scanning transmission electron microscopy with in situ differential phase contrast imaging was first used to study the initial activation mechanism of Li1.2 Ni0.13 Co0.13 Mn0.54 O2 . Li‐ion transport heterogeneity was observed in LLO grains and across the LLO/Li6 PS5 Cl interface, due to the coexistence of the nanoscale Li2 MnO3 and LiNi1/3 Co1/3 Mn1/3 O2 phases. Consequently, the severely constrained activation of Li2 MnO3 during the first charging could be attributed to a nanoscale phase separation in LLO, hindering Li‐ion transport through its particles, and causing high impedance in the Li2 MnO3 domain/Li6 PS5 Cl interface. This study could facilitate interface design of high‐performance LLO‐based ASSLBs. Abstract : HAADF and in situ DPC‐STEM were used to directly observe Li‐ion transport heterogeneity caused by phase separation, which elucidates the reason for the capacity limitation of Li‐rich layered oxides.