Interface Engineering of a Ceramic Electrolyte by Ta<sub>2</sub>O<sub>5</sub> Nanofilms for Ultrastable Lithium Metal Batteries
Sijie Guo, Tingting Wu, Yonggang Sun, Si‐Dong Zhang, Bing Li, Hong‐Shen Zhang, Mu‐Yao Qi, Xian‐Hu Liu, Amin Cao, Li‐Jun Wan
Abstract
Abstract Solid‐state batteries (SSBs) are promising for next‐generation energy storage with advantages in both energy density and safety, but are challenged by the poor solid‐to‐solid contact between solid‐state electrolytes (SSEs) and electrodes, particularly the lithium anode. Herein, a facile coordination‐assisted deposition process is employed to build artificial Ta 2 O 5 nanofilms on SSEs, which is lithiophilic and has high stability against metallic lithium, thereby ensuring an intimate and stable interface between SSEs and lithium anode to sustain extended cycles. The feasibility is verified by using Li 6.5 La 3 Zr 1.5 Ta 0.5 O 12 (LLZT), a garnet‐typed SSEs, as a model system. It is shown that a 12 nm Ta 2 O 5 nanofilm is able to significantly decrease the interfacial resistance from 1258 to 9 Ω cm 2 with a high critical current density reaching 2.0 mA cm −2 for the assembled symmetric cell, which shows an unprecedented capability to survive long‐term cycling over 5200 h. This control strategy is also able to enable the use of the commercialized cathode materials of LiFePO 4 and LiNi 0.83 Co 0.07 Mn 0.1 O 2 in SSBs with both high reversible capacity and cycling capability. The study opens up a research avenue for the delicately carved interlayers through a scalable and reliable manufacturing process which can accelerate the commercialization of SSEs.