Preparation And Properities Of Na₃SbS₄-and Na₁₁Sn₂PS₁₂-based Sulfide Solid Electrolytes

The use of soild electrolytes in all-solid-state battery can effectively avoid the safety problems of flammability,explosion,and leakage that caused by the shortcomings of poor thermal stability and toxicity of the electrolyte in the liquid battery.Moreover,due to the abundant resources of sodium and the low cost,the all-solid-state sodium-ion batteries are expected to be a substitute for lithium-ion batteries in large-scale energy storage systems.Sodium solid-state electrolyte,the core component of all-solid-state sodium-ion batteries,is vital important to optimize its ionic conductivity and electrochemical performance.In addition,because the interface impedance between the solid-state electrolytes and the electrode materials is large,optimizing the electrode-electrolyte interface can effectively improve the electrochemical performance of the all-solid-state batteries.In this paper,the Cl doped Na_3-xSbS_4-xCl_x（NSSC）solid-state electrolytes was prepared by solution method,and its structure and electrochemical performances were characterized and testd.Due to the introduction of vacanies after doping,the room temperature ionic conductivity of the electrolyte is improved.According to DSC and TG tests,it can be confirmed that Na₃SbS₄-8H₂O hydrate remain durinng the sampe preparation proccesss,and the decomposition products of the hydrate in contact with sodium metal can form a passivation layer at the electrode-electrolyte interface,and then play a protective role.In addition,due to the addition of Cl,the battery produces electronically insulated NaCl during the cycling,which can ease the reaction between the electrode-electrolyte interface.On the other hand,the nano-scale electrolyte particles prepared by the solution method can effectively buffer the volume change during the battery cycling.With FeS₂ as the positive electrode material,which is coated by NSSC-0.05 sample,the assembled all-solid-state batteries have good cycle performance and rate performance.In this paper,the O-doped Na₁₁Sn₂PS_12-x2-x O_x（NSPO）solid electrolyte was prepared by solid phase sintering method.The Raman results indicate that O was successfully incorporated into the Na₁₁Sn₂PS₁₂ crystal structure and replaced the position of S in the SnS4^4-tetrahedral structure.The air stability of the NSPO-1 sample with an O doping content of 1 is improved.And due to the incorporation of O,the compatibility of the electrolyte with sodium metal is improved,and the ability to resist dendrites becomes stronger.Moreover,In addition,the electrochemical impedance at different times of aging was tested,and the results showed that the interface impedance between the electrolyte after doping with O and metallic sodium was smaller and the electrochemical performance was more stable.Meanwhile,the introduction of O will enhance the interface compatibility between the electrolyte and the cathode materials.The all-solid-state battery SeSPAN/NSPO-1/Na assembled with NSPO-1 soild-state electrolyte has good cycle performance and rate performance.In this paper,a polymer electrolyte membrane PEO-NaFSI-NSS-PAN containing pbwioasl（syf（lsauyconrrtyohlseousnliifztoerindl.ye l））Di um（eiP dtAeo N（t）hN e a nFparSneIso）,ef inNbceaer3 So fbs Sik4ne l（oorNtgoSanSn,i）,c afpinolldle yrpe toNhlyyS（lSea cnareny ld o osnxoiitdrdiielu e m）（（PsPaElAtO N）N,）a sFskSoeIld,o ittuohmne ionic conductivity of the electrolyte membrane has been improved.The room temperature ionic conductivity of the PEO-NaFSI-NSS electrolyte film can reach 4.236×10^-5 S/cm.At the same time,the interfacial compatibility between the polymer electrolyte membrane and sodium has also been improved.PEO-NaFSI-NSS-PAN polymer electrolyte film has good mechanical properties to enhance its resistance to dendrites,because of the existence of PAN skeloton.