In-situ visualization of lithium plating in all-solid-state lithium-metal battery

Lithium metal with high theoretical specific capacity (3860 mAh/g) and the lowest electrochemical potential (−3.04 V vs standard hydrogen electrode) has been considered as the most promising anode material for next-generation rechargeable batteries. Since lithium readily reacts with most organic solvents, complete replacement of conventional electrolytes with solid electrolyte has attracted much attention. However, in solid-state lithium batteries uncontrollable lithium dendrites growth and large interface fluctuations during lithium plating/stripping still happens, leading to short circuit or capacity fading. This study employs Neutron Depth Profile (NDP), a unique tool with high sensitivity and high spatial resolution for lithium detection in solid device, to investigate the lithium plating behavior in Li|Li6.4La3Zr1.4Ta0.6O12 (LLZTO)|Ti solid-state battery with three-dimensional (3D) Ti electrode. The experiments, together with theoretical modeling, show that the majority of lithium can be deposited in the void space of the Ti 3D electrode which largely diminishes solid electrolyte/electrode interface degradation and suppresses lithium dendrite growth as well. This research demonstrates that a negative electrode with efficiently designed 3D framework can not only undertake the huge volume expansion during lithium plating but also regulate lithium deposition behavior to inhibit Li dendrite growth.