The Synthesis Of Sulfide Electrolyte And The Application In All-solid-state Li-S Battery

The demand for high energy,reliability and cyclability in emerging energy storage field makes Li-S batteries with theoretical energy density of 2600Wh kg^-11 stand out,but it was hard going for the shuttle effect,which is originated from the use of liquid electrolyte.With the development of solid electrolyte,especially the application of sulfide electrolytes with high ionic conductivity,the safety problems of lithium ion batteries have been solved.In addition,it takes effect on the suppressing poly-sulfides and the shuttle effect,this advantage brings great prospect to all-solid-state Li-S batteries.In this paper,we invest the synthesis methods in detail,they involve liquid method?magnetic stirring and emulsifying method?,solid method?ball milling?.The ionic conductivity of sulfide electrolyte Li₃PS₄ crystal prepared by liquid method is about1×10^-4S/cm,which is lower than Li₃PS₄ glass-ceramics(7×10^-4S/cm)with ball milling.Under the fundament of Li₃PS₄ glass-ceramics,we further explore the influence of ionic conductivity in all-solid-state Li-S batteries.The S/Super P composites are blending with Li₃PS₄glass-ceramics for electrode materials,then they are used to assemble all-solid-state Li-S batteries.While suppressing the forming of poly-sulfides,the all-solid-state Li-S batteries are still restricted with the problems of lower ionic conductivity and poor electrical conductivity in S electrode,the cycling performance of all-solid-state Li-S batteries is remaining to be improved.Hence,we set about adopting Black Peal 2000?BP2000?,a carbon material with high specific surface,to ameliorate the electrical conductivity of S via melting method.Meanwhile,we prepare Li₇P₃S₁₁1 glass-ceramics with ionic conductivity of 2×10^-3S/cm,and take it as the electrolyte of all-solid-state Li-S batteries,the electro-chemical performance has been vastly improved.While testing at 60?,S@BP2000|Li₇P₃S₁₁1 glass-ceramics|Li-In all-solid-state Li-S batteries exhibit substantial increase in rate performance?1076 mAh g^-11 at 4C,991 mAh g^-11 at 6C and 912 mAh g^-11 at 8C?and cycling performance?the capacity decreases 0.0035%per cycle and remains about 98.6%after 500 cycles?.When testing at 80?,the specific capacity(1570 mAh g^-1,0.2C)and rate performance?1299 mAh g^-11 at 4C,1204 mAh g^-11 at 6C and 1100 mAh g^-11 at 8C?are further improved,but the cycling performance of 3C is inferior to 60?,the specific capacity decreases 0.029%per cycle and can be kept at 82.4%after 500cycles,it is mainly caused by the physical pulverization and structural change of the electrolyte in ASSLSB.