One-dimensional H 2 V 3 O 8 nanorods and two-dimensional lamellar MXene composites as efficient cathode materials for aqueous rechargeable zinc ion batteries.

The energy crisis is a the worldwide problem which needs humans to solve immediately. To solve this problem, it is necessary to develop energy storage batteries. It is worth mentioning the aqueous rechargeable zinc ion batteries (ARZBs) which have some advantages, such as low cost, good safety and no need for an organic electrolyte as in the traditional lithium-ion batteries. However, it is still a challenge to find suitable and reliable electrode materials. In this work, as-prepared H 2 V 3 O 8 nanorods and MXene composites are used as cathode materials in ARZBs which were designed well using a hydrothermal method after optimizing the reaction time. The results showed that H 2 V 3 O 8 /MXene ARZBs could provide a good transport path for zinc ions, which were based on special 1D H 2 V 3 O 8 nanorods and 2D multi-layered MXene materials, which exhibited an outstanding initial specific discharge capacity of 373 mA h g -1 at 200 mA g -1 , good rate capability and a long lifecycle with only 15.8% capacity decay at 500 mA g -1 after 5000 cycles. The H 2 V 3 O 8 /MXene composites with a good electrochemical performance bring insight into their promising applications for energy storage batteries. They provided enhanced rate performance and excellent cycling stability, which was ascribed to the multi-step and multi-mode zinc ion insertion/extraction process. This was confirmed by the use of the 1D/2D integrated structure of the H 2 V 3 O 8 /MXene composites, which was conductive to zinc ion diffusion.