A wide-temperature superior ionic conductive polymer electrolyte for lithium metal battery. (July 2020)

• Record Type: Journal Article
• Authors: Lin, Zhiyuan; Guo, Xianwei; Wang, Zichun; Wang, Boya; He, Shiman; O'Dell, Luke A.; Huang, Jun; Li, Hong; Yu, Haijun; Chen, Liquan
• Is Part Of: Nano energy. Volume 73(2020)
• Publication Date: 2020-07
• Subjects: Poly(vinyl ethylene carboznate) polymer -- Polymer electrolyte -- Superior ionic conductivity -- Li ions transports mechanism -- In-situ polymerization; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2020.104786
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: Polymer electrolytes are one of promising candidates that can meet the demands of high safety and stability of high-energy lithium metal batteries. However, the practical applications of polymer electrolytes are usually limited by the low ionic conductivity, narrow electrochemical window and highly interfacial resistance. Here we designed a poly(vinyl ethylene carbonate) polymer electrolyte for polymer lithium metal battery by in-situ polymerization method. The new polymer electrolyte provides superior ionic conductivity with 2.1 × 10 −3 S cm −1 at 25 °C, wide electrochemical window up to 4.5 V ( vs . Li + /Li) and excellent interfacial compatibility to electrodes. The ions transports are mainly achieved from the coupling/decoupling between Li ions and oxygen atoms in CO groups, partially from the coupling/decoupling between Li + and oxygen atoms in C–O groups, and probably moving/exchange of Li + between CO and C–O groups in the process of segmental motions in high and low molecular polymers of polymer electrolyte. The lithium metal batteries with LiFePO4 cathode can deliver a high discharge capacity of ~165 mA h g −1 at 25 °C, and even ~104 mA h g −1 at −15 °C with current density of 0.1C. Therefore, the novel polymer electrolyte designed in this study is a promising candidate for high performances polymer lithium metal batteries. Graphical abstract: The practical applications of polymer electrolytes for high-energy lithium metal batteries are still hindered by low ionic conductivity and high interfacial resistance. Here, we proposed a novel poly (vinyl ethylene carbonate) polymer electrolyte for polymer lithium metal battery by in-situ polymerization method. The new polymer electrolyte provides superior ionic conductivity and excellent interfacial compatibility to electrodes. This work provides new design polymer electrolyte is the promising candidates for the practical application of polymer LMBs and could be applied for the flexible electrical devices with high energy density. Image 1 Highlights: Poly (vinyl ethylene carbonate) electrolyte with superior ionic conductivity of 2.1 × 10 −3 S cm −1 at 25 °C has been designed. The lithium battery with LiFePO4 can deliver high discharge capacity about 165 mA h g −1 at 25 °C, and 104 mA h g −1 at −15 °C. The ions transport reaction mechanism has been revealed from the coupling/decoupling between Li ions and oxygen atoms. Abstract : The superior ionic conductive poly (vinyl ethylene carbonate) polymer electrolyte with wide temperature and electrochemical window has been developed for polymer lithium metal batteries. The excellent interfacial compatibility between electrode and polymer electrolyte that achieved via in-situ polymerization process evidently reduces interfacial resistance toward polymer lithium metal batteries with improved electrochemical performances. This study has important implications in developing highly ionic conductive and stable polymer electrolyte for high-performance polymer lithium metal batteries.