Sputtering Preparation Of LiCoO₂ And LiPON Layers In All-solid State Thin Film Battery And One-time Construction Of Cells

All-solid-state thin-film battery has become the trend of micro energy devices with its high safety,high specific capacity,and high integration characteristics.It is widely used in microchips,microelectromechanical systems（MEMS）and other fields.As an important way to prepare thin film materials,the process Parameters of magnetron sputtering directly affect the structure and performance of thin films.The application of lithium phosphorus oxynitride（Li PON）solid-state electrolyte films is limited by the ionic conductivity,and there is a close relationship between the orientation of the cathode material lithium cobalt oxide and its electrochemical performance.Therefore,optimization of sputtering Parameters to obtain high-quality Li PON,Li Co O₂ has become the focus of current research.1.Lithium phosphate targets with densities up to 72.25%of theoretical density were prepared by segmental sintering method.On this basis,Li PON solid electrolyte films were prepared by sputtering under a mixed argon/nitrogen atmosphere using an RF power supply.The main preparation process Parameters including sputtering power（120 W,140 W,160 W）,nitrogen/argon flow rate ratio（7:3,5:5,3:7）and annealing temperature（200°C,400°C）on the ionic conductivity of the films were investigated,and the lithium in Li PON was replenished by placing sintered lithium oxide flakes on the target surface during sputtering.Conclusion:Low sputtering power 120 W,argon nitrogen ratio 3:7,and 200°C annealing are the most suitable Parameters for the preparation of Li PON films by magnetron sputtering under specific deposition conditions.2.Lithium cobalt oxide targets with a density of 66.13%of theoretical density and no delamination were prepared by the pre-sintering-segmental sintering method.On this basis,Li Co O₂ cathode films were prepared by RF magnetron sputtering under argon atmosphere.The effects of sputtering power（120 W,140 W,160 W）,substrate temperature（100°C,300°C）and annealing temperature（300°C,500°C）on the structure,surface morphology and orientation of Li Co O₂ thin films were investigated.When the sputtering power matches the annealing temperature（when the film growth rate matches the diffusion rate）,the surface morphology of Li Co O₂ films is excellent and has a desirable spindle shape.The annealing treatment resulted in ideal（003）,（104）orientation of Li Co O₂ films with flat and dense surfaces.3.An all-solid-state battery with electrolyte-coated cathode was designed and prepared by magnetron sputtering.The cell uses graphite negative electrode film,Li Co O₂ positive electrode film,and amorphous Li PON solid-state electrolyte film.The cell has a reasonable structure with well-defined layer structure and uniform and dense layers,and is discharged at 2.35 V at room temperature.