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

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.

Automated summary

Li-CO2 batteries, which utilize CO2 and have a high energy density, are hindered in practical applications due to slow kinetics and safety hazards. This study introduces a stable and highly conductive ceramic-based solid electrolyte and a metal-organic framework catalyst to improve the safety and performance of Li-CO2 batteries. The optimized Li-CO2 cell shows outstanding specific capacity and cycle life, and the post-cycling analysis reveals the degradation mechanism of the electrodes. First-principles calculations based on density functional theory are also performed to understand the interactions between the catalyst and the host electrode. This research demonstrates the potential of MOF cathode catalyst for stable operation in Li-CO2 batteries.