Preparation And Supercapacitor Performance Of NiCo₂O₄ Particles With Diamond-shaped Hexahedron Structure

Supercapacitor is a new type of energy storage device that is located between conventional capacitors and chemical power.Because of its highly power density,high efficiency,excellent charge and discharge characteristics,long life cycle,wide operating temperature range,environmental friendliness and safety,it is applied to many portable systems and hybrid cars as the best power source.The electrode material is an important part of the supercapacitor,which determines the electrochemical performance of the supercapacitor.In the past decade,transition metal oxides and hydroxides have been extensively studied as active electrode materials for Faraday capacitors.At the same time,mixed metal oxides come to the fore.The current electrode materials have some insufficient to meet the requirements of practical applications for supercapacitors.In order to solve these problems and further improve the properties of the electrode materials,the mixed metal oxide-NiCo₂O₄ crystal with a diamond-shaped hexahedron structure was prepared.The supercapacitor performances of Ni Co₂O₄ particles were studied in this research.The details are as follows:?1?NiCo₂O₄ particles were successfully synthesized by hydrothermal method.The analysis results of characterization show that the long diagonal of NiCo₂O₄ particles is about3.5?m,and the crystal has a cubic spinel structure.At the same time,the crystal growth theory was used to study the growth of NiCo₂O₄ crystal.The results show that during the growth of NiCo₂O₄ crystals,the auxiliaries,NH₄F and CO?NH₂?₂,play an important role.It determines that the final morphology of crystal is impacted by auxiliaries which affect the growth of crystal planes.?2?Electrochemical workstation was used to test the supercapacitor performance of NiCo₂O₄ particles.At the current density of 1.0 mA cm^-2,the specific capacitances of NiCo₂O₄-I and NiCo₂O₄-II electrodes are 690.75 F g^-1 and 1710.9 F g^-1,respectively.The NiCo₂O₄-II//AC asymmetric electrode has an energy density of 64.67 Wh kg^-1 at power density of 12 kW kg^-1.The results show that NiCo₂O₄ electrode with higher specific capacitance and excellent cycling stability has great potential for application in supercapacitors.As a supercapacitor electrode material,the diamond hexahedral sheet-structured NiCo₂O₄ particles are of excellent electrochemical performance,which shows good application potential and development prospects.