Rapid synthesis of two-dimensional MoB MBene anodes for high-performance sodium-ion batteries

Two-dimensional (2D) transition metal borides (MBenes) have emerged as a rising star and hold great potential promise for catalysis and metal ion batteries owing to a well-defined layered structure and excellent electrical conductivity. Unlike well-studied graphene, perovskite and MXene materials in various fields, the research about MBene is still in its infancy. The inadequate exploration of efficient etching methods impedes their further study. Herein, we put forward an efficient microwave-assisted hydrothermal alkaline solution etching strategy for exfoliating MoAlB MAB phase into 2D MoB MBenes with a well accordion-like structure, which displays a remarkable electrochemical performance in sodium ion batteries (SIBs) with a reversible specific capacity of 196.5 mAh g–1 at the current density of 50 mA g–1, and 138.6 mAh g–1 after 500 cycles at the current density of 0.5 A g–1. The underlying mechanism toward excellent electrochemical performance are revealed by comprehensive theoretical simulations. This work proves that MBene is a competitive candidate as the next generation anode of sodium ion batteries.