中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 34 No. 9 September 2024 |
（1. College of Chemistry and Chemical Engineering, Changsha University of Science and Technology, Changsha 410114, China;
2. Hunan Provincial Key Laboratory of Materials Protection for Electric Power and Transportation, Changsha University of Science and Technology, Changsha 410114, China;
3. College of New Energy, Ningbo University of Technology, Ningbo 315336, China）
Abstract:A composite solid electrolyte comprising a Cu-Al bimetallic metal-organic framework (CAB), lithium salt (LiTFSI) and polyethylene oxide (PEO) was fabricated through molecular grafting to enhance the ionic conductivity of the PEO-based electrolytes. Experimental and molecular dynamics simulation results indicated that the electrolyte with 10 wt.% CAB (PL-CAB-10%) exhibits high ionic conductivity (8.42×10-4 S/cm at 60 °C), high Li+ transference number (0.46), wide electrochemical window (4.91 V), good thermal stability, and outstanding mechanical properties. Furthermore, PL-CAB-10% exhibits excellent cycle stability in both Li-Li symmetric battery and Li/PL-CAB- 10%/LiFePO4 asymmetric battery setups. These enhanced performances are primarily attributable to the introduction of the versatile CAB. The abundant metal sites in CAB can react with TFSI- and PEO through Lewis acid–base interactions, promoting LiTFSI dissociation and improving ionic conductivity. Additionally, regular pores in CAB provide uniformly distributed sites for cation plating during cycling.
Key words: polyethylene oxide; Cu-Al bimetallic metal-organic framework; solid lithium metal battery; molecular grafting; ionic conductivity
