High Cathode Loading and Low-Temperature Operating Garnet-Based All-Solid-State Lithium Batteries - Material/Process/Architecture Optimization and Understanding of Cell Failure

All-solid-state lithium batteries (ASSLBs) are prepared using garnet-type solid electrolytes by quick liquid phase sintering (Q-LPS) without applying high pressure during the sintering. The cathode layers are quickly sintered with a heating rate of 50-100 K min(-1) and a dwell time of 10 min. The battery performance is dramatically improved by simultaneously optimizing materials, processes, and architectures, and the initial discharge capacity of the cell with a LiCoO2-loading of 8.1 mg reaches 1 mAh cm(-2) and 130 mAh g(-1) at 25 degrees C. The all-solid-state cell exhibits capacity at a reduced temperature (10 degrees C) or a relatively high rate (0.1 C) compared to the previous reports. The Q-LPS would be suitable for large-scale manufacturing of ASSLBs. The multiphysics analyses indicate that the internal stress reaches 1 GPa during charge/discharge, which would induce several mechanical failures of the cells: broken electron networks, broken ion networks, separation of interfaces, and delamination of layers. The experimental results also support these failures.

Automated summary

All-solid-state lithium batteries (ASSLBs) with garnet-type solid electrolytes are prepared using quick liquid phase sintering (Q-LPS) method. Through optimizing materials, processes, and architectures, the battery performance is significantly improved. The initial discharge capacity of the cell with LiCoO2 loading of 8.1 mg reaches 1 mAh cm(-2) and 130 mAh g(-1) at 25 degrees C. The Q-LPS method is suitable for large-scale manufacturing of ASSLBs.