Tailoring composites via in situ growth of Co-MOF on V2CTx MXene as high-performance anode for lithium-ion batteries

Abstract

MXenes, as a new family of 2D materials, have attracted extensive attention for their high electrical conductivity and good electrochemical cycling stability. However, due to the self-stacking nature of MXene materials, the actual specific capacity (260 mAh g−1) of V2CTx MXene materials as anodes is much lower than the theoretical specific capacity (940 mAh g−1). Herein, we designed a novel Co-MOF/V2CTx composite (denoted as Co-MOF/V2CTx), where Co-MOF was in situ grown on the surface and interlayer of the V2CTx MXene with larger interlayer spacing. The MOF in the composite provides the additional specific capacity as well as effectively prevented the restacking of V2CTx MXene, which exposed more Li+ active sites. Besides, benefiting from the high conductivity, electrochemical stability, and strong bonding with the Co-MOF at the interface of MXene, the structural stability of Co-MOF itself in composite materials can be better improved. Consequently, the cells with Co-MOF/V2CTx anodes realize a high specific capacity of 484.3 mAh g−1 after 120 cycles at 100 mA g−1 and superior cycling stability even at a higher current density of 500 mA g−1. The unique synergistic design of this work can provide new ideas for the development of MXene-based composites in energy storage applications.