Transport and mechanical aspects of all-solid-state lithium batteries

All-solid-state batteries (ASSBs) have been promoted as a highly promising energy storage technology due to the prospects of improved safety and a wider operating temperature range compared to their conventional liquid electrolyte-based counterparts. While solid electrolytes with ionic conductivities comparable to liquid electrolytes have been discovered, fabricating solid-state full cells with high areal capacities that can cycle at reasonable current densities remains a principal challenge. To overcome these challenges, a quantitative and in-depth understanding of the phenomena governing ionic and electronic transport limitations within the cathode composite, in addition to mechanical aspects arising from significant volume changes associated with Li metal anodes (including anode-less cell designs) are needed. Such understanding can be obtained from proper electrochemical measurements described herein. In this review we seek to highlight solutions to these existing challenges and several directions for future work are proposed.