Rational design of Co sub-nano clusters by electronic metal-support interaction for inducing Li2O2 growth

Abstract

The cathodic electrocatalyst for Li-O2 battery with rich and effective active sites was significant to optimize the formation and decomposition of Li2O2, improve the discharge-charge kinetics. Herein, we develop a novel strategy to controllably prepare sub-nano clusters modified carbon materials. The sub-nano cluster of Co was anchored on the Ketjen Black (KB) substrate and achieved electrocatalytic performance promotion via rational design of the electronic metal-support interaction (EMSI), where the numerous sites in KB with large specific area and geometric space were activated. The experimental and theoretical results indicated that the substrate of the carbon plane could be strongly coupled with the metal atoms and optimized the electronic structure of carbon, leading to effective tuning for Li2O2 growth. The composite exhibited superior performance with high specific capacity of 15311 mAh g−1, low overpotential of 0.88 V and long-term durability of more than 140 cycles with 1000 mAh g−1, strongly related with the optimized Li2O2 growth and decomposition in battery operation. It provides a new strategy for novel electrocatalyst design to tuning the Li2O2 related process.