A fibrotic poly (ethylene oxide) polymer electrolyte with high ionic conductivity for stable lithium metal batteries

Abstract

Lithium metal battery (LMB) is considered to be the most promising next generation secondary battery. However, the low ionic conductivity and high interfacial impedance between solid electrolyte and electrode are the main factors to limit the real application of solid electrolyte in LMBs. In this work, we designed a low resistance LMB with excellent electrochemical performance applying the electrospun poly (ethylene oxide) (PEO) with super low crystallinity as the electrolyte and LiPF6 in EC/EMC/DMC as the plasticizer. The electrospun PEO shows an ionic conductivity of 1.27 mS cm− 1 at 30 °C, which result from its amorphous region and fibrotic structure to accommodate large amount of liquid electrolyte without leakage. The electrochemical window can be 5.0 V (vs. Li/Li+). The obtained electrospun PEO presented robust electrochemical surface stability and could effectively restrain the dendrite growth. The Li symmetric cells using electrospun PEO can stably cycle for 800 h without short circuit at 0.1 mA cm− 2. The study proposed a robust and scalable battery structure with outstanding electrochemical properties.