Poly(ethylene oxide) reinforced Li6PS5Cl composite solid electrolyte for all-solid-state lithium battery: Enhanced electrochemical performance, mechanical property and interfacial stability

Argyrodite Li 6 PS 5 Cl is a promising solid electrolyte in all-solid-state lithium batteries owing to its high ionic conductivity . However, the poor mechanical property and undesirable interfacial property restrict its application. In order to solve these issues, we fabricate Li 6 PS 5 Cl/poly(ethylene oxide) composite solid electrolytes with enhanced mechanical property and stable lithium/electrolyte interface. By adding 5 to 20 wt% poly(ethylene oxide), the proportional limit of composite solid electrolytes is enhanced by ∼150%, reaching a value up to 60 MPa. With 5 wt% poly(ethylene oxide), the as-assembled sandwich-type LiNi 0 · 8 Co 0 · 1 Mn 0 · 1 O 2 /composite solid electrolytes/Li battery exhibits enhanced cycling performance with a capacity retention rate of 91% over 200 cycles at 0.05C and 30 °C. Ex situ characterizations reveal that by adding suitable poly(ethylene oxide) content in Li 6 PS 5 Cl, the interfacial reactions and lithium dendrite growth can be effectively inhibited, resulting in much improved cycling performance of all-solid-state lithium batteries.