An effective LiBO2 coating to ameliorate the cathode/electrolyte interfacial issues of LiNi0.6Co0.2Mn0.2O2 in solid-state Li batteries

• Published in: Journal of power sources Vol. 426; pp. 242 - 249
• Main Authors: Zhang, Xu-Dong, Shi, Ji-Lei, Liang, Jia-Yan, Wang, Li-Ping, Yin, Ya-Xia, Jiang, Ke-Cheng, Guo, Yu-Guo
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 30.06.2019
• Subjects: Cathode materials; Cycling stability; Interfacial chemistry; Power performance; Solid-state batteries; Power performance; Cycling stability; Cathode materials; Interfacial chemistry; Solid-state batteries
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2019.04.017

Solid-state batteries provide a safe and high energy density solution to next-generation energy storage devices. However, unsatisfactory power capability and cycling stability raised from lithium diffusion resistance and catalytic reaction at the electrode/electrolyte interface critically restrict their development. In this study, these interfacial issues are ameliorated by LiBO2 coating to achieve the successful implementation of nickel-rich LiNi0.6Co0.2Mn0.2O2 in poly(ether-acrylate) based solid-state batteries. The continuous coating acts not only as a physical barrier hindering the decomposition of polymer electrolyte but also as a buffer layer promoting lithium diffusion across the space charge layer owing to its electronic insulativity and ionic conductivity. In consequence, the LiBO2 coated nickel-rich cathode delivers superior cycling stability with a capacity retention of 84.3% during 150 cycles at 0.5C, remarkably improved lithium diffusion kinetics with an order of magnitude increase in apparent diffusion coefficient and prominent power performance with 97 mA h g−1 at 2C. The effectiveness of inserting such functional interlayer emphasizes the essentiality of interfacial chemistry in building high-performance solid-state Li metal batteries. [Display omitted] •LiBO2 coating is constructed on nickel-rich layered LiNi0.6Co0.2Mn0.2O2.•Coating provides a physical barrier against decomposition of polymer electrolyte.•LiBO2 suppresses the space charge layer and promotes interfacial ion diffusion.•Cathode shows improved cycling and power capability in solid-state batteries.