Cationic metal-organic framework derived ruthenium-copper nano-alloys in porous carbon to catalytically boost the cycle life of Li-CO2 batteries.

ABSTRACT

Rechargeable Li-CO2 batteries are an innovative energy storage technology with broad application prospects owing to their superb energy density and ability to capture the greenhouse gas CO2. However, they are still suffering from severe challenges in the formation and decomposition of electrochemically sluggish Li2CO3 discharge products, resulting in poor battery performance. Development of an efficient cathodic electrocatalyst has the potential to address these issues by catalytically boosting the conversion of Li2CO3. Herein, we have designed a Ru-Cu nanoalloy decorated porous carbon (Ru-Cu@NPC) material derived from an anion-exchanged cationic MOF, and it can serve as an efficient cathode electrocatalyst for Li-CO2 batteries. Benefitting from the uniform distribution of ultrafine Ru-Cu nanoalloys with high catalytic performance, Ru-Cu@NPC displays excellent CO2 reduction and evolution activities. Impressively, the Li-CO2 battery with the Ru-Cu@NPC catalyst exhibits a remarkably low potential gap of 0.93 V at 100 mA g-1 and a stable discharge/charge cycling performance of more than 400 cycles at a high current density of 400 mA g-1 within a limiting capacity of 1000 mA h g-1. The study provides an opportunity for the research of cationic MOF derived bimetallic catalysts in the Li-CO2 battery field.