Construction of high-capacity and high-stability La-doped VO2(B) supported on mesoporous hollow carbon spheres and their cathode performance in zinc-ion batteries

This study employs a synergistic strategy combining La 3+ -doped modified VO 2 (B) (L x VO) with mesoporous hollow carbon spheres (MHCS) to prepare a high-capacity, highly stable MHCS-supported La-doped VO 2 (B) cathode material (HLVO). Optimizes the La 3+ doping ratio of L x VO and the MHCS content in HLVO, and the lattice expansion behavior of VO 2 (B) caused by La 3+ doping and the composite of carbon materials is clarified, which effectively contributes to the improvement of Zn 2+ diffusion kinetics rate and electrochemical performance of HLVO. The dynamic mechanism of LVO and HLVO is explained by density functional theory. The results show that the (110) interplanar spacing of 5 % La-doped L 0.05 VO increases to 0.355 nm. In the optimized H2L 0.05 VO, L 0.05 VO loose nanorods and MHCS are evenly distributed. The diffusion kinetic rate constant of Zn 2+ in HLVO is two orders of magnitude higher than that of VO 2 (B). At 1 A g −1 , the specific capacity of H2L 0.05 VO cathode remains at 403.5 mAh g −1 after 200 cycles, and the capacity retention rate is as high as 81.6 % after 10 A g −1 10000 cycles. The synergistic strategy of rare earth doping and carbon material composite provides a new idea for the development of high-performance aqueous zinc ion batteries (AZIBs) cathode materials.