Te-doped Fe3O4 flower enabling low overpotential cycling of Li−CO2 batteries at high current density

Abstract

Li−CO2 batteries (LCBs) suffer from high overpotentials caused by sluggish CO2 reaction kinetics. This work designs a Te-doped Fe3O4 (Te-Fe3O4) flower-like microsphere catalyst to lower the overpotential and improve the reversibility of LCBs. Experimental results reveal that Te doping modifies the electronic structure of Fe3O4 and reduces the overpotential. The stable Te−O bond between Te and C2O42− could effectively inhibit the disproportionation reaction of the latter, enabling the Te-Fe3O4 cathodes to exhibit a remarkable capacity (9485 mAh g−1) and a long cycling life (155 cycles) with an overpotential of 1.21 V and an energy efficiency of about 80% at a high current density (2000 mA g−1). Through the interaction between Te and Li2C2O4 to inhibit the disproportionation reaction, this work successfully achieves long-term cycling of LCBs with low overpotential at high current density.