Preparation And Electrochemical Properties Of Some Materials Containing Nickel And Manganese

With the large consumption of fossil fuels,energy and environmental problems are becoming increasingly serious.A large number of research and practice have led to the emergence of numerous new power generation schemes,and people have more demand for excellent energy storage equipment.In order to realize the sustainable development of economy and environment,supercapacitor,a low-cost and environmentally friendly energy storage device,is undoubtedly the best choice.In this paper,three traditional supercapacitor materials,nickel molybdate,nickel cobalt hydroxide and manganese dioxide,have been studied.Carbon doping was used to modify nickel molybdate and manganese dioxide to improve their electrochemical properties.After that,a new type of zinc-ion battery device was made by combining the theory of flexible electrode material with nickel cobalt hydroxide and manganese dioxide,and its test was carried out.Firstly,we synthesized nickel cobalt hydroxides by hydrothermal method,and tested them by scanning electron microscopy?SEM?and X-ray diffraction?XRD?.In the SEM test,the flexible collector with a conductive shell is hydrothermally grown into layered nickel-cobalt hydroxides.The layered nickel-cobalt hydroxides are interlaced and cross each other to form a highly conductive path.The subsequent cyclic voltammetry and charge-discharge tests also show that the flexible nickel-cobalt hydroxide electrode has a large specific capacity,ranging from 0 to 0.8V.There are 300mAh·g^-11 in the perimeter.The specific capacity can be maintained above 280mA HG-1at the rate of 1C.With the increase of the rate,the specific capacity decreases gradually.After 25C,the capacity of the battery still keeps about 200 mAh·g^-1,which shows that the electrochemical performance is superior.Comparing the test electrodes with the two reference electrodes,all the samples have a small difference at 1C?approximate to three samples,about 98%?and maintain a high capacity.But when 5C,the gap gradually widens and the difference becomes very big.For example,the relative capacities of flexible electrode samples at 5C and 20C are 97%and 83%,which are higher than those of nanosheet reference samples?95%at 5C and 69%at 20C?and traditional electrode reference samples?94%at 5C and 53%at 20C?.In this paper,manganese dioxide was synthesized by electrode position.Similarly,carbon nanotubes were used to form a dense conductive shell on the fibers,on which the active substances grew in petal-like structure.Each petal interlaces to form a conductive pathway.This flexible manganese dioxide electrode has a current density of about 2 mA·cm^-2and a potential difference of about 2 V at potential of 0.5 and 0.6 V.The capacity of the battery at 1C can be maintained at 300 mAh·g^-1,while the capacity of the battery at 5C can be maintained at about 250 mAh·g^-1.It can maintain 90%or higher capacity before 3C.Even at 25C,the capacity of the battery is still about 60%,which has better electrochemical performance.In contrast,at 15C,the difference began to increase,with 83%of the flexible electrode samples and 64%and 47%of the other two samples,respectively.Through the testing and characterization of the above materials,it can be seen that the flexible electrode has better electrochemical performance,stable performance,large capacitance and excellent electrochemical performance,which provides a new scheme for flexible wearable energy storage equipment.