Architecting P-doped MoO2/Mo2CTx heterostructures with rich oxygen vacancies toward superior lithium storage

The application of Mo 2 CT x MXene as an anode for lithium-ion batteries (LIBs) is severely limited by the little electrochemical active sites and large diffusion energy barrier of lithium ions. Creating heterostructures between MXene and high-performance secondary materials with unique structure and tunable electron arrangement is an effective strategy. Herein, the heterostructure of P-doped MoO 2 and Mo 2 CT x (Mo 2 CT x /MoO 2 -P) with built-in-electric field and rich oxygen vacancies is constructed to co-regulate the electrochemical performance of battery. This design enables the material with high electronic density of states, improved ability of lithium adsorption and diffusion as well as strong structural stability. As a result, the as-prepared Mo 2 CT x /MoO 2 -P anode delivers excellent rate performance (301.3 mAh g −1 at 5 A g −1 ) and long cycle stability (1062.13 mAh g −1 at 1350 cycles at 2 A g −1 and 345.5 mAh g −1 at 4500 cycles at 5 A g −1 ), which are superior to that of previously reported Mo 2 CT x -based anode materials. Moreover, the Mo 2 CT x /MoO 2 -P||LiCoO 2 full cell offers 341.4 mAh g −1 after 200 cycles at 1 A g −1 , confirming the practicality of Mo 2 CT x /MoO 2 -P.