Preparation Of Nano-ZnO Coated With Two-dimensional Materials And Study On The Performance Of Zn-Ni Battery

The growth of zinc dendrite is an important factor affecting the cycling performance of Zn Ni battery.During the cycling process,zinc dendrite will grow into needle shape,which will change the electrode volume and seriously break through the seperater,resulting in short circuit of the battery.In order to prolong the cycle performance of Zn/Ni batteries,it is necessary to limit the growth of zinc dendrite.In this paper,nano ZnO was used as the main anode material to prepare the reduced graphene oxide / nano ZnO and mxene / reduced graphene oxide composite electrodes,and their electrochemical properties were studied.Firstly,nano ZnO was prepared by hydrothermal method as anode base material.ZnO nanoparticles are embedded in xerogel of reduced graphene oxide to form ZnO/reduced graphene oxide composites via a simple one-step hydrothermal treatment.As anode in Zn/Ni batteries,the as-prepared ZnO/reduced graphene oxide composites exhibit high specific capacity(～580 m Ah/g at 6.5 A/g)and excellent cycling stability(stable within 1700cycles)in 6M KOH electrolyte saturated with ZnO.The introduction of reduce graphene oxide xerogel in the composites is found to immensely improve the electron transfer and long-term cycling stability of the composites.The as-prepared composites are extremely promising as anode in Zn/Ni batteries considering their facile preparation and superb electrochemical performance.In addition,the MXene material obtained by etching MAX with hydrofluoric acid was mixed with nano ZnO in aqueous solution and then filtered to obtain MXene / nano ZnO Composite as anode.MXene has better coating effect on ZnO nanoparticles.The material has high cycle performance and electrochemical working platform.The discharge capacity of ～ 550 m Ah / g can be maintained at a current density of 3.3A/g.The cycle performance can last more than 3000 times.Both of the two composite materials can improve the cycle life of the anode and maintain excellent discharge capacity,which has a good application prospect in zinc nickel battery.