A High Capacity‐Long Cycling Concurrent Strategy of Ti 3 C 2 /MgH 2 for Lithium Storage

ABSTRACT The excellent electrical conductivity and superior cycling stability render Ti 3 C 2 MXene a promising Li ion battery anode. Nevertheless, the practical implementation of Ti 3 C 2 MXene in commercial applications faces significant challenges, predominantly due to the low specific capacity. MgH 2 , a typical hydrogen storage material, exhibits extraordinary lithium storage capacity, but it faces severe cycling stability issues. Aiming at combining the merits of both MXene and MgH 2 while circumventing their drawbacks, we investigate the electrochemical performance of Ti 3 C 2 /MgH 2 composites as anodes for lithium‐ion batteries. The composites were synthesized by ball milling with varying mass ratios of Ti 3 C 2 MXene and MgH 2 , followed by dehydrogenation–hydrogenation treatment for the optimized ratio. Structural and morphological analyses confirm the uniform distribution of MgH 2 within the Ti 3 C 2 matrix, with enhanced crystallinity and interfacial interactions after dehydrogenation–hydrogenation. The hydrogenated composite with the optimum ratio, named as MX/MH‐5/2‐res, exhibits superior electrochemical properties, including high initial discharge capacity (1416.3 mAh g −1 ), excellent cycling stability (434.4 mAh g −1 after 140 cycles at 0.1 A g −1 ), and outstanding rate capability (217.1 mAh g −1 at 5 A g −1 ). Cyclic voltammetry and electrochemical impedance spectroscopy reveal improved reaction kinetics and reduced charge transfer resistance (114.3 Ω) due to enhanced interfacial binding between Ti 3 C 2 and MgH 2 . Theoretical study unveils the underlying cause for enhanced Li interfacial binding through a combination of work function, charge density, and crystal orbital Hamilton population analyses. Our study paves the way for dehydrogenation–hydrogen initiation of the MXene/MgH 2 composites to achieve high‐performance lithium‐ion battery anodes.