A rechargeable lithium/quinone battery using a commercial polymer electrolyte
Résumé
The present study reports superior electrochemical performance with capacity doubled for organic positive electrodes based on a small redox-active molecule when using the Lithium Metal Polymer (LMP) technology. Particularly, the simple use of the regular solid polymer electrolyte currently employed in commercial LMP cells allows obtaining for the first time an efficient two-electron cycling of tetramethoxy-p-benzoquinone with high-rate capability at temperatures as high as 100 °C. With no optimization, the restored capacity represents 80% of the theoretical value (190 mAh/g) after 20 cycles operated at a C rate. On the contrary, when cycled in conventional carbonate-based electrolytes, this quinone compound exhibits quite poor electrochemical features such as a very limited depth of discharge (~ 50% of the theoretical capacity in the first cycle) followed by rapid capacity decay. After cycling, preliminary post-mortem characterizations did not evidence any obvious degradation in the cell. Although the adverse effect of the diffusion of the active material is not fully inhibited, the coulombic efficiency is close to 100% while the Li/electrolyte interface appears stable.