The Preparation And Lithium Storage Characteristics Based On Perovskite Fluorine/oxide Electrode Materials

Nowadays,the sustainable development of countries in the world is hindered by energy and environmental issues,but the market demand for high-performance energy storage equipment is increasing.Lithium-ion capacitors(LICs)and lithium-based dual-ion batteries(Li-DIBs)are two new lithium-based energy storage devices that adapt to the development of the times,they have received widespread attention because of their high energy density,high power density and long cycle life.The electrode materials largely determine the performance of the device,so the development of high-performance electrode materials is the key to improving the performance of the device.In this paper,two perovskite-type electrode materials are synthesized,and they are used as anode materials to explore their application prospects in LICs and Li-DIBs.The main research work are as follows:1.A low-cost tetragonal phase single-metal perovskite fluoride KCu F₃(denoted as KCF)is prepared by solvothermal method.The physical and chemical properties of KCF material are studied by XRD,SEM,TEM and BET tests.A variety of ex-situ tests revealed that the KCF material is pseudocapacitive controlled and conversion mechanism about Li-ion storage.In the half-cell test,KCF shows excellent performance(75.1-52.5 m A h g^-1/0.1-3.2 A g^-1/191%retention/1000 cycles/1 A g^-1).The KCF//AC LIC and KCF//918 Li-DIB are respectively assembled by KCF and commercial activated carbon(AC)and graphite(918),and all devices show excellent electrochemical performance(70.0-14.2 Wh kg^-1/0.8-22.2 k W kg^-1/60%remain/3000cycles/4 A g^-1;70.5-9.4 Wh kg^-1/1.0-9.2 k W kg^-1/65%remain/2000 cycles/4 A g^-1).It shows that KCu F₃ material has development prospects in the field of new lithium-based energy storage devices,and the price advantage of KCu F₃ material promotes the development of low-cost energy storage systems.2.The Ni/Co/Mn tri-metals perovskite oxide microsphere material LaNi Co Mn O₃(Ni:Co:Mn=1:1:1)(denoted as LNCMO(1:1:1))is prepared by mixed solvothermal method.The physical and chemical properties of LNCMO(1:1:1)material are studied by XRD,SEM,TEM and BET tests.The ex-situ XPS,XRD and CV tests prove that the LNCMO(1:1:1)material is pseudocapacitive controlled and conversion-insertion hybrid mechanisms about Li-ion storage.The half-cell test result shows that the LNCMO(1:1:1)material has better overall electrochemical performance than the corresponding three single metal materials(266.5-149.3 m Ah g^-1/0.1-3.2 A g^-1/129%remain/2 A g^-1/1000 cycles).The LNCMO(1:1:1)//AC LIC and LNCMO(1:1:1)//KS6Li-DIB are respectively assembled by LNCMO(1:1:1)and commercial activated carbon(AC)and graphite(KS6),and all devices show excellent electrochemical performance(122.1-32.5 Wh kg^-1/0.6-18 k W kg^-1/56%remain/1000 cycles/5 A g^-1;194.8-8.7 Wh kg^-1/0.7-10.4 kW kg^-1/64% remain/500 cycles/2 A g^-1).