Improving the Conductivity of Solid Polymer Electrolyte by Grain Reforming

• Main Authors: Zhaohuan Wei, Yaqi Ren, Minkang Wang, Jijun He, Weirong Huo, Hui Tang
• Format: Article
• Language: English
• Published: SpringerOpen 2020-05-01
• Series: Nanoscale Research Letters
• Subjects: Solid-state electrolyte; Polyethylene oxide; Grain boundary; Reforming; Li-ion battery
• Online Access: http://link.springer.com/article/10.1186/s11671-020-03355-4

Abstract Polyethylene oxide (PEO)-based solid polymer electrolyte (SPE) is considered to have great application prospects in all-solid-state li-ion batteries. However, the application of PEO-based SPEs is hindered by the relatively low ionic conductivity, which strongly depends on its crystallinity and density of grain boundaries. In this work, a simple and effective press-rolling method is applied to reduce the crystallinity of PEO-based SPEs for the first time. With the rolled PEO-based SPE, the LiFePO4/SPE/Li all-solid li-ion battery delivers a superior rechargeable specific capacity of 162.6 mAh g−1 with a discharge-charge voltage gap of 60 mV at a current density of 0.2 C with a much lower capacity decay rate. The improvement of electrochemical properties can be attributed to the press-rolling method, leading to a doubling conductivity and reduced activation energy compared with that of electrolyte prepared by traditional cast method. The present work provides an effective and easy-to-use grain reforming method for SPE, worthy of future application.