Defects‐Abundant Ga<sub>2</sub>O<sub>3</sub> Nanobricks Enabled Multifunctional Solid Polymer Electrolyte for Superior Lithium‐Metal Batteries
Huixue Li, Xijun Xu, Fangkun Li, Jingwei Zhao, Shaomin Ji, Jun Liu, Yanping Huo
Abstract
Abstract Polyethylene oxide (PEO)‐based polymer electrolytes with good flexibility and viscoelasticity, low interfacial resistance, and fabricating cost have caught worldwide attention, but their practical application is still hampered by the instability at high voltages and the low ionic conductivity (10 −8 to 10 −6 S cm −1 ). Herein, we rationally designed defects‐abundant Ga 2 O 3 nanobricks as multifunctional fillers and constructed a PEO‐based organic‐inorganic electrolyte for lithium metal batteries. Due to the abundant O‐defects feature of Ga 2 O 3 filler, this PEO‐based composite electrolyte not only broadens electrochemical stability window (over 5.3 V versus Li/Li + ) but also in situ forms a Li–Ga alloy and solid electrolyte interphase (SEI) film during the cycling process causing a rapid diffusion of Li + ions. The as‐prepared electrolyte has good interface compatibility with Li metal (without short‐circuiting over 500 h at 0.2 mA cm −2 ) and possesses superior high ionic conductivity. The assembled all‐solid‐state LiFePO 4 //Li cells attained an excellent cycling performance of 146 mAh g −1 over 100 cycles at 0.5 C. The XPS analysis reveals that Ga 2 O 3 nanobricks can form in situ a Li−Ga alloy layer at the polymer/anode interface. This work shed a light on designing high ionic conductivity lithium alloys in the composite electrolyte, which can improve the electrochemical properties of PEO‐based polymer electrolytes.