Interfacial electronic structure design of MXene-based electrocatalyst via vacancy modulation for lithium-oxygen battery

Abstract Vacancy induced electronic structure design is considered as one of the most promising strategies to develop remarkable electrocatalysts for lithium-oxygen battery (LOB) due to its ability to tuning electronic properties and enhancing electronic migration rate. Herein, regulation of electronic structure is realized by introducing oxygen vacancy into SnO2 on Ti3C2Tx MXene (Vo-SnO2/Ti3C2Tx), which acts as physical scaffold to form a stable interface. The fully exposed active sites combining the heterogeneous interface is favorable for optimizing the adsorption capability of Vo-SnO2/Ti3C2Tx for intermediate species and promoting interfacial charge transfer, which will accelerate the kinetics of both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). The high round-trip efficiency (84%), large specific capacity (18648 mA h g−1) and extended cyclability with low overpotential (200 cycles) of the Vo-SnO2/Ti3C2Tx based LOBs experimentally confirm its superior electrocatalytic activity. This study provides a general approach for developing superior electrocatalysts via electronic structure modulation for high performance LOBs.