Microbial-derived functional carbon decorated hollow NiCo-LDHs nanoflowers as a highly efficient catalyst for Li-CO2 battery

Abstract

As a promising method for CO2 capture and utilization, Li-CO2 battery is attracting significant attention due to its uniqueness in low-carbon technology and high output energy density. However, the practical application is plagued by the sluggish electrochemical reaction kinetic and difficult decomposition of Li2CO3. Herein, we propose a strategy to realize high capacity, large rate capability and good stability Li-CO2 battery by inducing the growth of Li2CO3 along the base face of hollow NiCo-LDHs nanoflowers. The unique morphology of the NiCo-LDHs nanoflowers make sure numerous exposed active sites and enough space for the reversible electrochemical reaction in Li-CO2 battery. Meanwhile, microbial-derived functional carbon (M-FC) is prepared to decorate the petals of the NiCo-LDHs nanoflowers, which can provide both superior electrical conductivity and co-catalyst effects to accelerate the kinetics of the electrochemical reaction. Due to the deliberate design and the synergy effect of the M-FC and NiCo-LDHs nanoflowers, the Li-CO2 battery using M-FC/NiCo-LDHs cathode exhibits a high discharge capacity (13756.8 mA h g−1), enhanced rate capability (up to 2000 mA g−1) and excellent cyclability (for 60 cycles) under optimized condition. This work opens a promising avenue for the design of high performance catalyst and the recycling utilization of hazardous microbial wastes.