Metal-organic-framework-modified composite polymer electrolyte with high interfacial compatibility for stable Li metal all-solid-state battery

• Published in: Materials letters 2024-06, Vol.365, p.136416, Article 136416
• Main Authors: Yu, Litao, Pang, Tianlu, Li, Yande, Zhang, Hui, Yu, Yi, Zhang, Nian
• Format: Article
• Language: English
• Subjects: Energy storage and conversion; Polymeric composites; Porous materials; X-Ray techniques
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2024.136416

•Introducing Mg-MOF to polymer matrix enhances the property of electrolyte membrane.•Mg K-edge EXAFS reveals the cross-linking mechanism in the membrane.•The Li/CPE-10/Li symmetrical battery works well for more than 2000 h.•Battery using NCM811 cathode shows an excellent cycle performance. To enhance the compatibility between the electrolyte and electrode in a Li metal all-solid-state battery, a composite polymer electrolyte (CPE) modified with a metal–organic framework (MOF) is utilized. The Mg ligands in Mg-MOF-74 are connected to the F site in polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) and lithium salt, forming a robust cross-linking network. Due to the abundant pores in the Mg-MOF-74 skeleton, this cross-linking membrane not only secures the polymer chains but also provides large and uniform Li+ transport channels. The CPE membrane demonstrates high ionic conductivity (2.94 × 10-4 S·cm−1) and a wide electrochemical stability window (4.95 V). Utilizing a high-voltage LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode, the all-solid-state battery exhibits stable cycle performance and an exceptional capacity retention rate of 90.16 % after 100 cycles.