Boosting the cycle life of solid-state Li–CO2 battery through integration of a polymer/ceramic composite electrolyte

The Li–CO₂ battery, capable of both efficient carbon dioxide fixation and high energy density storage, holds promise in mitigating the greenhouse effect and alleviating mileage anxiety. However, the volatilization/leakage problems of the conventional electrolytes and the dendrites crisis of lithium anode seriously affect the battery life. The replacement of the organic electrolyte with a solid one is a feasible method to solve the above problems. Till now, the poor interface contact between solid electrolyte and electrode restricts the Li⁺ ions transport kinetics in discharge/charge cycles. Herein, we apply a solution casting method to prepare a flexible polymer/ceramic composite electrolyte. With the combination of high Li⁺ ions conductivity ceramic filler of Zn-doped Li_1.3Al_0.3Ti_1.7(PO₄)₃ (LATP) and Lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) active additive, the crystallization of polyvinylidene fluoride (PVDF) and poly (ethylene oxide) (PEO) is suppressed, thus efficiently enhancing the room temperature Li⁺ ions conductivity (8.32 × 10⁻⁴ S cm⁻¹) of the composite electrolyte. The Li–CO₂ battery with the solid-state electrolyte exhibits a high discharge capacity (32,842 mAh g⁻¹) and long stable cycles (over 220 cycles). The polymer/ceramic composite electrolyte design presents a novel approach to realizing solid-state Li–CO₂ batteries with long-term cycling performance.