Preparation Of Sulfur-based Solid Electrolyte And Study On Its Interface With Dissimilar Materials

All-solid-state batteries with sulfide-based solid electrolytes have attracted significant attention as next-generation energy storage devices because of their long life performances,high energy densities,and high power densities.These advantages arise from specificcharacteristics of the sulfide-based solid electrolytes,which exhibit high ionic conductivities,a high lithium-ion transportnumber of 1.In particular,the sulfide-based solid electrolytes possess favorable mechanical properties,allowing all-solid-state ells to be easily prepared via simple mixing and cold-pressing processes.However,for practical application,a simple synthesis process for the sulfide-based solid electrolytes and effective manufacturing process for the all-solid-state cells are required.In this paper,we successfully prepared Li₁₀GeP₂S₁₂,a lithium ion conductor material with high lithium ion conductivity,and the influence of different heat treatment temperatures on electrolyte performance was explored.The room temperature ionic conductivity,electrochemical window,thermal stability and chemical stability have been measured.It was determined that the ionic conductivity of the electrolytes treated at 700?was the best,4.92×10^-3 S·cm^-1 at room temperature.Through the dc polarization test,the electronic conductance of electrolyte was calculated to be 10^-8 S·cm^-1,and the electrolyte remained stable below 5 V.We coatedlithium cobalt oxide with lithium phosphate,which can improve the battery capacity.The polymer is added as a buffer material interface,to fill the void space,form a good interface contact between the electrode and the electrolyte to solve the interface problem..The cycle stability of the battery is good,the limiting current density is increased to 1.0 mA·cm^-2,and the constant current charge and discharge cycle can be continued for 700 h,and the polarization voltage is stable.The sulfide electrolyte with soft polymer interface,lithium metal electrode assembled all-solid battery,the first specific capacity can reach 300 mAh·g^-1 under the condition of 0.05 C,whether using powder sintered material or tablet sintering The material has good cycle stability,indicating that as an interface layer,the polymer can effectively improve the cycle stability of the solid state battery,and at the same time,the LGPS electrolyte is separated,which hinders the side reaction between the lithium metal negative electrode and the lithium metal negative electrode to a certain extent,thereby reducing the resulting irreversible capacity loss.