In situ decoration of CoP/Ti3C2Tx composite as efficient electrocatalyst for Li-oxygen battery

Abstract

Application of Li-oxygen (Li-O2) battery is in urgent need of bifunctional ORR/OER electrocatalyst. A surface-functionalization CoP/Ti3C2Tx composite was fabricated theoretically, with the optimized electronic structure and more active electron, which is beneficial to the electrochemical reaction. The accordion shaped Ti3C2Tx is featured with large specific surface area and outstanding electronic conductivity, which is beneficial for the adequate exposure of active sites and the deposition of Li2O2. Transition metal phosphides provide more electrocatalytic active sites and present good electrocatalytic effect. The CoP/Ti3C2Tx composite served as the electrocatalyst of Li-O2 battery reaches a high specific discharge capacity of 17,413 mAh/g at 100 mA/g and the lower overpotential of 1.25 V, superior to those of the CoP and Ti3C2Tx individually. The composite of transition metal phosphides and MXene are applied in Li-O2 battery, not only demonstrating higher cycling stability of the prepared CoP/Ti3C2Tx composite, but pointing out the direction for their electrochemical performance improvement.