A gel polymer electrolyte film based on chitosan derivative and ionic liquid for the LiFePO4 cathode solid Li metal battery

作者：Guo, Yue; Chen, Xixi; Xie, Yu^*; Shen, Zhen; Ling, Yun; Xue, Xiaoyuan; Tong, Yongfen; Wang, Jiangli; Zhang, Wei; Zhao, Jie^*

来源：Materials Today Communications, 2022, 31: 103597.

DOI：10.1016/j.mtcomm.2022.103597

• Chitosan derivatives
• Gel polymer electrolytes
• Ionic liquids
• Li metal batteries
• LiFePO 4

Solid electrolytes can improve the safety of Li metal batteries. However, the performance of solid electrolyte is still not satisfactory due to its poor high-temperature stability, low ionic conductivity, and poor interface stability/compatibility with electrodes. By combining chitosan-based polymer substrates with ionic liquids, we designed and synthesized two types of solid gel polymer electrolyte (SGPE, i.e., HA-BF4 and HA-TFSI) films. The optimal SGPE film (i.e., HA-BF4-80) exhibited good high-temperature stability (270 degrees C), high ionic conductivity (2.03 x 10 & xe213; 3 S cm & xe213; 1 at 35 degrees C), and excellent interface stability/compatibility with electrodes. It had a wide electrochemical window of 4.60 V and high Li+ transport number of 0.54. With LiFePO4 as the cathode, the HABF4-80 SGPE film as solid electrolyte, and the Li metal as anode, the Li|HA-BF4-80|LiFePO4 displayed a higher specific capacity of 152 mAh g & xe213; 1 and excellent cycle performance with a capacity retention of 82% even after 100 cycles underscoring the significant potential applications of HA-BF4-80 SGPE film in solid lithium metal batteries. This work would have an important value in the design and development of the high-performance SGPE films.

• 单位
  郑州大学; 南昌航空大学; y; 南京大学