Nanoporous Metal Phosphide For High Performance Nickel-zinc/Bismuth Battery

In recent years,the development of battery technology has greatly promoted the development of electric vehicles and hybrid vehicles.Among many battery systems,nickel-zinc batteries are expected to become strong competitors to replace lead-acid batteries,nickel-metal hydride batteries,and nickel-cadmium batteries in the field of power batteries due to their advantages of ultra-high power density,rapid charge and discharge,and high operating voltage.However,in traditional nickel-zinc batteries,the cathodic material,nickel hydroxide or oxide,has a poor conductivity.And the addition of polymer binders during the electrode preparation increases the contact resistance and sacrifices part of the activity,which directly affects the device performance.The three-dimensional nanoporous metal has a self-supporting open-pore structure,which has the advantages of a high conductivity and a high specific surface area.These metal nanoporous structures,which combine the physical chemistry and mechanical characteristics o f bulk materials with the advantages of nanostructured materials,are expected to play a positive role in improving the performance of nickel-based batteries.Therefore,this research focuses on the application of nanoporous metals in nickel-based batteries.The main research contents include:(1)Ni₉₀P₁₀ binary dual-phase alloy was prepared by rapid solidification.Single-phase self-supporting nanoporous metal phosphide was successfully prepared by simple electrochemical corrosion.This special structure c an provide a greater specific surface area,more abundant active sites,and a faster electron transfer.Thanks to the good conductivity of the self-supporting electrode,the effective charge transfer at the active material interface and the rapid ion diffu sion through the electrode channels,the nickel-zinc battery exhibits excellent rate performance and cycle performance stability(retained after 6000 cycles rate of 94%).Combined with its good electrochemical stability and excellent rate performance,this new type of nanoporous metal phosphide shows a great potential for practical nickel-based batteries.(2)As a new type of anode material,bismuth has a highly reversible redox reaction and a wide negative potential working window in alkaline electrolyte.The Bi₂₀In₈₀ binary alloy prepared by rapid solidification was used to prepare the porous bismuth by corrosion as a self-supporting electrode.The capacity and stability of the nickel-bismuth battery showed a significant improvement.The improvement is resulted from the self-supporting conductive matrix and the active substance grown in situ.This endows nanoporous bismuth a certain application prospect as an anode material.