A Free-Standing α-MoO/MXene Composite Anode for High-Performance Lithium Storage.

Replacing the commercial graphite anode in Li-ion batteries with pseudocapacitor materials is an effective way to obtain high-performance energy storage devices. α-MoO is an attractive pseudocapacitor electrode material due to its theoretical capacity of 1117 mAh g. Nevertheless, its low conductivity greatly limits its electrochemical performance. MXene is often used as a 2D conductive substrate and flexible framework for the development of a non-binder electrode because of its unparalleled electronic conductivity and excellent mechanical flexibility. Herein, a free-standing α-MoO/MXene composite anode with a high specific capacity and an outstanding rate capability was prepared using a green and simple method. The resultant α-MoO/MXene composite electrode combines the advantages of each of the two components and possesses improved Li diffusion kinetics. In particular, this α-MoO/MXene free-standing electrode exhibited a high Li storage capacity (1008 mAh g at 0.1 A g) and an outstanding rate capability (172 mAh g at 10 A g), as well as a much extended cycling stability (500 cycles at 0.5 A g). Furthermore, a full cell was fabricated using commercial LiFePO as the cathode, which displayed a high Li storage capacity of 160 mAh g with an outstanding rate performance (48 mAh g at 1 A g). We believe that our research reveals new possibilities for the development of an advanced free-standing electrode from pseudocapacitive materials for high-performance Li-ion storage.