Preparation And Ultracapacitance Properties Of Co-Ni-base Metal Compounds Electrode Materials

In order to cope with the energy shortage in today’s society,it is necessary to develop sustainable energy devices that can be applied to energy storage and clean and efficient urgently.As a new type of energy storage device,supercapacitors（SCs）have attracted extensive attention and research..They have the advantages of short charge and discharge time,friendly working conditions,high power density and long cycle life,while taking into account the small size of the device,environmental protection and maintenance-free features,so that it can not only meet the high power requirements of large equipment,but also meet the demand for some small equipment that does not replace the power supply for a long time has been widely used in the field of electronics and new energy.Nowadays,the lower energy density is still the biggest resistance for the practical application of SCs,hindering the development of supercapacitors.The energy density is mainly affected by two factors:1.Specific capacitance;2.Operating voltage.Therefore,researchers are committed to developing electrode materials with higher specific capacitance and developing new assembly methods.It can be seen that the electrode material is the technical focus to solve the performance of the supercapacitor,so this paper mainly explores the electrode material of the transition metal（Ni,Co）compound while providing a high specific capacitance while solving the rate performance of the material Poor problem.The details are as follows:1.The electrode material of cobalt nickel carbonate hydroxide grown on the foamed nickel substrate by a simple hydrothermal method.The unique structural features can promote the rapid diffusion of electrolyte and the rapid transfer of electrons.The prepared material showed a higher specific capacity(1346.4 F g^-1 at the moderate current density of 3 A g^-1)and excellent rate characteristics（in the binder-free electrode material）stabilize at 935.4 F g^-1 as the current density increases to 20 A g^-1.At the same time,a series of comparative tests were conducted to confirm that the NP-3 material has application prospects.2.Through the engineering design of the surface structure of high-performance supercapacitors,the multi-dimensional structure of the Co Ni₂S₄ electrode material was reasonably designed（two-dimensional microchip/one-dimensional nanowire/two-dimensional ultra-thin nanoplate crosslinking）.The preparation of a special morphology is highly dependent on the synergy between the Co-Ni precursor array and the subsequent vulcanization process.The unique Co Ni₂S₄ electrode material（NS-3）provides a significantly enhanced specific capacitance(specific capacitance of 3784.6F g^-1 at a current density of 3 A g^-1),while having excellent rate performance(specific capacitance of 2932.3 F g^-1 at current density of 20 A g^-1)and excellent cycle life.3.Prepare asymmetric supercapacitor（ACS）equipment to further explore the practical application capabilities of NS-3.The asymmetric device based on NS-3 as the positive electrode and activated carbon as the negative electrode shows that high energy density of 38.46 Wh kg^-1 at a power density of 374.9 W kg^-1 and the energy density is 22 Wh kg^-1 at a power density of 7615.4 W kg^-1.The results show that the design of multi-dimensional Co-Ni-S materials is an effective strategy to achieve a high-performance supercapacitor.