All-Solid-State Batteries With Sulfide-Antimony-Based And Pcl-Based Solid Electrolyte

All-solid-state sodium-ion batteries are promising for large energy storage,because of its abundant resources,low cost,high safety and excellent high and low temperature performance.Solid electrolyte is the key point of all-solid-state battery.The prerequisite for practical application of all-solid-state batteries is to explore solid electrolyte with high ionic conductivity and good interface stability.In addition,polymer electrolyte has a good flexibility,which can effectively solve the interface problem of inorganic solid electrolyte because of the good contact between electrolyte and electrodes.Explorasion of new polymer electrolytes is a hot topic.In this study,the vacancy-contained solid electrolyte Na₃SbS₄ with a tetragonal structure was successfully synthesized by molten-sintering process,and its structure and electrochemical properties were investigated for the first time.The results show the existence of 2.5 mol.%Na vacancies at Na2 sites,benefit from these favorable structure features,this electrolyte shows prominent performance with high ionic conductivity and fast ion diffusion.In addition,a comprehensive research coupling experiment and computation has been performed to understand the phase transition of Na₃SbS₄ and its impact on ion transport.Cubic Na₃SbS₄ was successfully synthesized by high energy ball milling,its structure and electrochemical properties were investigated;both experiment and theoretical calculation reveal that the electrochemical properties of cubic Na₃SbS₄ is superior to tetrognal Na₃SbS₄.All-solid-state batteries with cubic Na₃SbS₄ solid electrolyte demonstrate relatively good cycling stability.Considering the fragility and high interfacial resistance of inorganic electrolyte,we explored the polymer electrolyte that with good interfacial stability.The polymer electrolytes were prepared by solution casting PCL/SN blends integrating with PAN-skeleton.This polymer electrolyte exhibits good mechanical and electrochemical properties.Additionally,it demonstrates superior stability and interface compatibility toward electrodes.The all solid-state cells based on this electrolyte deliver outstanding cycling stability and superior rate capability.