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

• Published in: Rare metals 2022, Vol.41 (1), p.106-114
• Main Authors: Ren, Hao-Tian, Zhang, Zi-Qi, Zhang, Jun-Zhao, Peng, Lin-Feng, He, Zhen-Yuan, Yu, Ming, Yu, Chuang, Zhang, Long, Xie, Jia, Cheng, Shi-Jie
• Format: Article
• Language: English
• Subjects: Additives; Biomaterials; Cathodes; Chemistry and Materials Science; Compatibility; Discharge; Electrolytes; Energy; Flux density; Ion currents; Lithium; Lithium batteries; Lithium oxides; Materials Engineering; Materials Science; Metallic Materials; Moisture; Molten salt electrolytes; Nanoscale Science and Technology; Original Article; Physical Chemistry; Solid electrolytes; Solid state; Stability
• ISSN: 1001-0521; 1867-7185
• DOI: 10.1007/s12598-021-01804-2

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 Li 2 O additives. 65Li 2 S–30P 2 S 5 –1%Li 2 O delivered the highest conductivity, while 65Li 2 S–30P 2 S 5 –5%Li 2 O showed the best moisture stability and improved lithium compatibility. Solid-state batteries using 65Li 2 S–30P 2 S 5 –5%Li 2 O electrolyte and high-voltage LiNi 0.6 Mn 0.2 Co 0.2 O 2 cathode exhibited low initial discharge capacity (100 mAh·g −1 ) and Coulombic efficiency (69%). Li 3 InCl 6 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·g −1 ) and improved initial Coulombic efficiency (86%). Moreover, it also exhibited good performance at − 20 °C. Graphical abstract