Facile preparation of MoO3@Mo2CT x nanocomposite with high lithium storage performance by in situ oxidation

Abstract

In this work, a new MoO3@Mo2CT x nanocomposite was prepared from two–dimensional (2D) Mo2CT x MXene by in situ oxidization in air, which exhibited wonderful lithium-storage performance as anodes of lithium–ion batteries (LIBs). The precursor Mo2CT x was synthesized from Mo2Ga2C by selective etching of NH4F at 180 °C for 24 h. Thereafter, the Mo2CT x was oxidized in air at 450 °C for 30 min to obtain MoO3@Mo2CT x nanocomposite. In the composite, in situ generated MoO3 nanocrystals pillar the layer structure of Mo2CT x MXene, which increases the interlayer space of Mo2CT x for Li storage and enhances the structure stability of the composite. Mo2CT x 2D sheets provide a conductive substrate for MoO3 nanocrystals to enhance the Li+ accessibility. As anodes of LIBs, the final discharge specific capacity of the MoO3@Mo2CT x composite was 511.1 mAh g–1 at a current density of 500 mA g–1 after 100 cycles, which is about 36.7 times that of pure Mo2CT x MXene (13.9 mAh g–1) and 3.2 times that of pure MoO3 (159.9 mAh g–1). In the composites, both Mo2CT x and MoO3 provide high lithium storage capacity and can enhance the performance of each other. Moreover, this composite can be made by a facile method of in situ oxidation. Therefore, the MoO3@Mo2CT x MXene nanocomposite is a promising anode of LIB with high performance.