Improvement of stability and solid-state battery performances of annealed 70Li2S-30P2S5 electrolytes by additives

The replacement of liquid electrolyte with solid electrolyte can significantly improve the safety and power/energy density of lithium batteries. 70Li(2)S-30P(2)S(5) is one of the most promising solid electrolytes with high conductivity for solid-state batteries. In this work, the ionic conductivity and stability toward moisture and lithium metal of 70Li(2)S-30P(2)S(5) were enhanced by introducing the different amounts of Li2O additives. 65Li(2)S-30P(2)S(5)-1%Li2O delivered the highest conductivity, while 65Li(2)S-30P(2)S(5)-5%Li2O showed the best moisture stability and improved lithium compatibility. Solid-state batteries using 65Li(2)S-30P(2)S(5)-5%Li2O electrolyte and high-voltage LiNi0.6Mn0.2Co0.2O2 cathode exhibited low initial discharge capacity (100 mAh center dot g(-1)) and Coulombic efficiency (69%). Li3InCl6 electrolytes were introduced both in the cathode mixture to replace sulfide electrolyte and in the interface layer to improve the cathode compatibility for the solid-state batteries, showing enhanced discharge capacity (175 mAh center dot g(-1)) and improved initial Coulombic efficiency (86%). Moreover, it also exhibited good performance at - 20 degrees C.

Automated summary

The replacement of liquid electrolyte with solid electrolyte can improve the safety and power density of lithium batteries. Adding Li2O to 70Li(2)S-30P(2)S(5) enhances its ionic conductivity and stability, while 65Li(2)S-30P(2)S(5)-5%Li2O shows improved moisture stability and lithium compatibility. Li3InCl6 electrolytes in cathode mixture and interface layer improve the performance of solid-state batteries.