Fast decomposition of Li2CO3/C actuated by single-atom catalysts for Li-CO2 batteries

Abstract

Lithium carbon dioxide (Li-CO2) batteries deliver a theoretical energy density of 1876 W h kg−1 in terms of effective utilization of greenhouse gases. This battery system is considered to be an encouraging electrochemical energy storage device and a promising alternative to Li-ion batteries. However, the main drawback of Li-CO2 batteries is their accumulative discharge product of Li2CO3/C, which leads to large overpotential and poor cycling performance. Thus, specific and efficient catalysts must be explored to enhance the decomposition of Li2CO3/C. Single-atom catalysts (SACs) are regarded as promising heterogeneous catalysts owing to their maximized utilization of metal atoms and strong interfacial electronic interactions. Herein, single-metal atoms of Fe, Co, and Ni uniformly anchored on N-doped reduced graphene oxide (rGO), designated as Fe1/N-rGO, Co1/N-rGO, and Ni1/N-rGO, respectively, are designed and fabricated to investigate their catalytic activity toward the decomposition of Li2CO3/C. Among them, Fe1/N-rGO delivers a high discharge capacity of 16,835 mA h g−1 at 100 mA g−1 and maintains stability for more than 170 cycles with a discharge voltage of 2.30 V at 400 mA g−1. Therefore, this catalysts are overwhelmingly superior to other types. This work reveals the advances of SACs in Li-CO2 batteries and offers an effective method for realizing high-performance Li-CO2 batteries.