Study On Layered Double Hydroxide Composite Materials And Its Electrochemical Performance In Supercapacitors

Faced with increasingly severe energy and environmental issues,it is imperative to develop new energy sources and all kinds of new energy storage devices.Supercapacitors have received widespread attention among various energy storage devices due to their excellent power density and specific capacitance.However,its application is limited by low energy density in various energy storage devices.Therefore,it is necessary to develop high-performance electrode materials.Layered double hydroxides（LDHs）are considered to be an excellent pseudo-capacitance material,with low manufacturing cost and eco-friendliness.However,due to their poor conductivity,they cannot be fully applied.The introduction of conductive polymers and carbon materials can effectively improve its electrochemical performance.In this paper,the polypyrrole/Ni Co-layered double hydroxide（PPy/Ni Co-LDH）nanocomposite was prepared by chemical oxidative polymerization method and co-precipitation.The effect of reaction temperature on the microscopic morphology of Ni Co-LDH and the influence of different feed ratios on polypyrrole were investigated.The influence of Ni Co-LDH on the electrochemical performance.The Ni Co-LDH was grown on polypyrrole as conductive substrate,and the synergistic enhancement effect of LDH and PPy was studied.The research results show that the introduction of conductive polymers can effectively improve the electrochemical performance.The electrochemical performance of the PPy/Ni Co-LDH-3 electrode material is the best.When the current density is 1 A·g^-1,the specific capacitance is as high as 1330 F·g^-1.It is assembled with activated carbon to form an asymmetric supercapacitor,which delivered a high energy density of 24.64 Wh·kg^-1 at the corresponding power density of 700.66 W·kg^-1The one-step solvothermal method assisted by freeze-drying method was used to grow Ni Co-LDH nanosheets on a three-dimensional graphene aerogel（GA）carrier to prepare Ni Co-LDH/graphene aerogel（Ni Co-LDH/GA）composite materials,studied the effect of different molar ratios of Ni:Co on the properties of composite materials.The research results show that when the molar ratio of Ni:Co is 3:1,the Ni Co-LDH/GA-1 composite has excellent specific capacitance(when the current density is 1 A·g^-1,the specific capacitance of the composite is 1897.5 F·g^-1).