Fan Zhao,Siqi Gong,Huiting Xu,Meng Li,Lina Li,Junjie Qi,Honghai Wang,Zhiying Wang,Yuqi Hu,Xiaobin Fan,Chunli Li,Jiapeng Liu
Rechargeable aqueous zinc-ion batteries are emerged as fascinating “beyond Li-ion” battery technologies for large-scale energy storage due to low cost, high theoretical capacity, high safety and environmental friendliness . However, developing cathode materials with outstanding electrochemical performance are prerequisites. Herein, the a-V 2 O 5 @Ti 3 C 2 T x heterostructure is prepared by in situ incorporating amorphous V 2 O 5 with Ti 3 C 2 T x MXene to enhance the rechargeable aqueous Zn-ion batteries performance. Benefitting from the distinctive amorphous structure of a-V 2 O 5 , outstanding conductivity of Ti 3 C 2 T x MXene and the strong synergistic effect between two components, the a-V 2 O 5 @Ti 3 C 2 T x heterostructure presents isotropic ion diffusion paths , plentiful ion storage sites and splendid conductivity. As a consequence, the a-V 2 O 5 @Ti 3 C 2 T x heterostructure displays excellent specific capacity of 544 mAh g −1 at 0.5 A g −1 and outstanding rate performance. Particularly, even at a fairly high current density of 30 A g −1 , the a-V 2 O 5 @Ti 3 C 2 T x heterostructure shows an impressive specific capacity of 135 mAh g −1 along with about 100% coulombic efficiency after 1000 cycles. Furthermore, the mechanism related is expounded via comprehensive characterizations. Therefore, this work offers a way for developing high-performance vanadium-based cathode materials for aqueous zinc-ion batteries.
Weiwei Wang,Rui Huang,He Peng,Ruiting Hu,Ling Ran,Yu Tao,Li Yani,Jun Yan
The emerging aqueous Zn-ion batteries (ZIBs) with their low price and inherent safety are showing strong competitiveness in the energy storage field. In this work, layer-by-layer stacked amorphous V 2 O 5 @Ti 3 C 2 T x heterostructures anchored on three-dimensional carbon cloth (3D CC), synthesized by annealing process and subsequent in-situ electrochemical induction, are reported as high capacity and stable cathode for ZIBs . In this composite cathode, amorphous V 2 O 5 @Ti 3 C 2 T x synergistic heterostructure provides isotropic Zn 2+ migration channels and rapid electron transfer kinetics, while the 3D CC substrate can ensure that the bulk phase in the electrode material is also utilized to maximize the synergistic effect. As a result, the CC/a-V 2 O 5 @Ti 3 C 2 Ti x cathode achieves a high specific capacity of 567 mAh/g at 0.1 A/g, a satisfactory rate performance of 213 mAh/g at 10 A/g, together with a long cycle life of 96.2 % capacity retention after 2000 cycles. Ex-situ characterizations show that the CC/a-V 2 O 5 @Ti 3 C 2 T x cathode undergoes a highly reversible Zn 2+ /H + co-intercalation/deintercalation mechanism during the discharge/charging process. In addition, based on the CC/a-V 2 O 5 @Ti 3 C 2 T x cathode, the assembled flexible ZIB can operate properly under different bending degrees, showing its practicality in flexible devices. This work provides insight into the rational design of cathode materials with high Zn-storage performance.
Jun Zheng,Chenyang Zhan,Kai Zhang,Wenwu Fu,Qiaojun Nie,Ming Zhang,Zhongrong Shen
Graphical Cellmates : A zinc-ion battery cell is constructed with V 2 O 3 @C as the cathode and a “water-in-salt” electrolyte. Electrochemically induced oxidation of V 2 O 3 @C into amorphous V 2 O 5 with in situ Zn 2+ and H 2 O co-insertion leads to excellent cycling and rate performances. Systematic improvement of this architecture indicates significant promise for practical application. Aqueous Zn-ion batteries (ZIBs), with the advantages of low cost, high safety, and high capacity, have great potential for application in grid energy storage and wearable flexible devices. However, their commercial application is still restricted by their inferior long-term cycling stability, Zn dendrite formation, and the decomposition of aqueous electrolyte. In this study, a Zn|Zn(CF 3 SO 3 ) 2 +LiTFSI|V 2 O 3 @C cell is constructed to address the above issues. The V 2 O 3 @C electrode can be fully oxidized into amorphous V 2 O 5 @C simultaneously with Zn 2+ and H 2 O co-insertion. The cell delivers a high specific capacity of more than 240 mAh g −1 at 3 A g −1 , with extraordinary coulombic efficiency and capacity retention. The excellent electrochemical performances are attributed to synergistic effects between the V 2 O 3 @C electrode and the water-in-salt electrolyte with enhanced stability and improved interface reaction kinetics. Systematic improvements of this architecture indicate much promise for application.
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