Highly efficient Li-CO2 batteries with regulated discharge product enabled by a hetero-structured N-C/Fe3C/Fe cathodic catalyst

Lithium carbon dioxide (Li-CO2) 2 ) batteries have been regarded as a promising technology to alleviate the greenhouse effect and meet the demands for high-energy applications. However, the sluggish CO2 2 transformation kinetics and the Li2CO3-related 2 CO 3-related parasitic reactions degrade the battery's performance. Herein, we introduce a heterostructure N-doped carbon combined Fe3C/Fe 3 C/Fe as a low-cost catalyst to regulate the formation of discharged product and accelerate the CO2 2 redox kinetics. Systematically experimental characterizations reveal that the as- designed heterostructure can control the discharge product as the amorphous form to reduce the polarization voltage, thereby improving the cycle stability and increasing the energy efficiency of the battery. As a result, the assembled Li-CO2 2 batteries exhibit a high full discharge capacity of 16550 mAh g- 1 with an excellent initial Coulombic efficiency of 96.7 % and maintain a low overpotential of 1.42 V over 200 cycles at 300 mA g- 1 . This work provides a new research insight to design high-efficient and low-cost Li-CO2 2 batteries with small over- potential and long-lifespan.