Ta<sub>4</sub>C<sub>3</sub>-Modulated MOF-Derived 3D Crosslinking Network of VO<sub>2</sub>(B)@Ta<sub>4</sub>C<sub>3</sub> for High-Performance Aqueous Zinc Ion Batteries
Weicai Liu, Hui Zong, Mengshu Li, Ziquan Zeng, Shijing Gong, Ke Yu, Z. Q. Zhu
Abstract
A two - dimensional MXene (Ta 4 C 3 ) was innovatively used herein to modulate the space group and electronic properties of vanadium oxides, and the MXene/metal–organic framework (MOF) derivative VO 2 (B)@Ta 4 C 3 with 3D network cross - linking was prepared, which was then employed as a cathode to improve the performance of aqueous zinc ion batteries (ZIBs). A novel method combining HCl/LiF and hydrothermal treatments was used to etch Ta 4 AlC 3 to obtain a large amount of accordion-like Ta 4 C 3, and the V-MOF was then hydrothermally grown on the surface of the stripped Ta 4 C 3 MXene. During the annealing process of V-MOF@Ta 4 C 3, the addition of Ta 4 C 3 MXene liberates the V-MOF from agglomerative stacking, allowing it to show additional active sites. More significantly, Ta 4 C 3 prevents the V-MOF in the composite structure from converting into V 2 O 5 of space group Pmmn but into VO 2 (B) of space group C 2/ m after annealing. A considerable advantage of VO 2 (B) for Zn 2+ intercalation is provided by the negligible structural transformation during the intercalation process and the special tunnel transport channels, which have an enormous area (0.82 nm 2 along the b axis). According to first-principles calculations, there is a strong interfacial interaction between VO 2 (B) and Ta 4 C 3, which deliver remarkable electrochemical activity and kinetic performances for the storage of Zn 2+ . Therefore, the ZIBs prepared with the VO 2 (B)@Ta 4 C 3 cathode material exhibit an ultra-high capacity of 437 mA h·g –1 at 0.1 A·g –1 while showing good cycle performance and dynamic performance. This study will offer a fresh approach and a reference for creating metal oxide/MXene composite structures.