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

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 SnO 2 on Ti 3 C 2 Tx MXene (Vo-SnO 2 /Ti 3 C 2 Tx), 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-SnO 2 /Ti 3 C 2 Tx 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-SnO 2 /Ti 3 C 2 Tx 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.