Realizing Stable Carbonate Electrolytes in Li-O2/CO2 Batteries†

Comprehensive SummaryThe increasing demand for high-energy storage systems has propelled the development of Li-air batteries and Li-O-2/CO2 batteries to elucidate the mechanism and extend battery life. However, the high charge voltage of Li2CO3 accelerates the decomposition of traditional sulfone and ether electrolytes, thus adopting high-voltage electrolytes in Li-O-2/CO2 batteries is vital to achieve a stable battery system. Herein, we adopt a commercial carbonate electrolyte to prove its excellent suitability in Li-O-2/CO2 batteries. The generated superoxide can be captured by CO2 to form less aggressive intermediates, stabilizing the carbonate electrolyte without reactive oxygen species induced decomposition. In addition, this electrolyte permits the Li metal plating/stripping with a significantly improved reversibility, enabling the possibility of using ultra-thin Li anode. Benefiting from the good rechargeability of Li2CO3, less cathode passivation, and stabilized Li anode in carbonate electrolyte, the Li-O-2/CO2 battery demonstrates a long cycling lifetime of 167 cycles at 0.1 mA & BULL;cm(-2) and 0.25 mAh & BULL;cm(-2). This work paves a new avenue for optimizing carbonate-based electrolytes for Li-O-2 and Li-O-2/CO2 batteries.

Automated summary

In this study, a commercial carbonate electrolyte was proven to be suitable for Li-O-2/CO2 batteries. The electrolyte captured superoxide and reacted with CO2 to form less aggressive intermediates, stabilizing the carbonate electrolyte and avoiding decomposition induced by reactive oxygen species. Additionally, the carbonate electrolyte greatly improved the reversibility of Li metal plating/stripping, enabling the possibility of using ultra-thin Li anode.