Preparation And Electrochemical Performance Of Electrode Materials For Alkaline Batteries

With the increasing shortage of energy resources,people's awareness of environmental protection is gradually enhanced,and the development of different types of clean energy to replace non-renewable fossil energy and alleviate environmental pollution has attracted extensive attention.Wind power,Solar energy and water energy are limited by the local environment and the high transportation cost.As a new energy,battery has aroused extensive research of scientists.Aqueous alkaline rechargeable battery has the advantages of safety and low cost,and its specific power is better than that of lithium ion battery and specific energy better than supercapacitors.They are widely used in portable electronic devices,large-scale energy storage devices and electric vehicles.Unfortunately,its limited current energy density and poor cycling stability greatly hinders its practical application.The main reason is the lack of high-performance electrode materials.Therefore,is an urgent need to design and preparation of high-performance electrode materials to realize the practical application of alkaline batteries.In this paper various electrode materials energy storage mechanism and the latest research progress were proposed.We also proposes a solution to solve poor conductivity and low utilization rate of alkaline battery electrode materials.(1)The combination of excellent mechanical properties and electrochemical performances of Ni-based cathodes is fascinating and challenging for the Ni-Zn batteries.Herein,a novel and eco-friendly strategy of the cycle of Ni²⁺hydrolysis and H⁺etching process at Ni/solution interface under moderate temperature is demonstrated to synthesize the three-dimensional NiO nanosheets array supported on pressed Ni foam electrode(denoted as NiO/PNF).Impressively,the as-prepared NiO/PNF electrode exhibits outstanding mechanical flexibility and stability with a capacity of 5.08m Ah cm^-3.The assembled NiO/PNF||Zn battery presents peak energy and power densities up to 5.2 m W h cm^-3and 1944.4 m W cm^-3.(2)Electrospinning technology and high temperature calcination were used to prepared Bi nanoparticles encapsulated in porous nitrogen-doped carbon nanofibers(denote as Bi@NPCF)and porous carbon coated bismuth metal nanofiber material(denote as Bi@PCF).By adding dicyandiamine,the content of N is increased to improve the electrical conductivity of the material,and the specific surface area of the material is increased at the same time.With abundant micropores Bi@NPCF is more conducive to the penetration of electrolyte and ion/electron transport.The electrochemical results showed that Bi@NPCF exhibited excellent electrochemical propertie especially the ultra-long cycle stability(after10000 cycles maintain 116.95%).The results of cyclic voltammetry test(CV)and constant current charge-discharge test(GCD)show that Bi@NPCF has a higher capacity than Bi@PCF.Its high performance due to the unique structure,which brings high atom utilization and rapid reaction kinetics of electrochemical reactions.The assembled NiCo₂O₄|Bi@NPCF battery presents excellent electrochemical performance,especially cyclic stability(after 5000 cycles maintain 95.86%).Also presents peak energy and power densities reached 100.89 Wh kg^-1and 38 k W kg^-1.