Safe and stable Li–CO2 battery with metal-organic framework derived cathode composite and solid electrolyte

Abstract

Li–CO2 batteries receive wide attention due to their strategic utilization of CO2 and high energy density. However, their practical application is hindered by sluggish kinetics and safety hazards. Herein, a stable and highly conductive ceramic-based solid electrolyte (Li1.4Al0.4Ti1.6(PO4)3) is used to enhance the safety aspect. In contrast, a metal-organic framework (MOF) based catalyst is introduced to ensure low polarization and long cycle life for Li–CO2 batteries. The as-prepared Li–CO2 cell delivers an outstanding maximum specific capacity of 6698 mA h g−1 at 100 mA g−1 current density. Besides, the cell shows a stable performance over 100 cycles of charge-discharge with a cut-off capacity of 500 mA h g−1. Later, the post-cycling analysis is performed to evaluate the electrode degradation mechanism. Further, to understand the interactions between the Co3O4-based catalyst and carbon-based host electrode with discharge product, we perform first-principles calculations based on density functional theory. This work shows great potential for the use of MOF cathode catalyst in Li–CO2 battery and is believed to be particularly promising for a stable operation.