钠离子电池聚合物电解质研究进展

Progress on polymer electrolyte in sodium ion batteries

近年来钠离子电池的能量、功率密度与循环寿命均得到了长足发展,然而常规电解液/隔膜体系由于易燃、易挥发,导致钠离子电池存在严峻安全隐患。为了提高钠离子电池的安全性,近年来固态电解质得到了广泛的关注,尤其以聚合物为基底的固态、凝胶电解质得到了快速发展。本文首先梳理了聚合物电解质基础的发展脉络与研究常用的理论模型,接着综述了固态与凝胶两类聚合物电解质在钠离子电池中的应用研究进展,对涉及的不同材料改性技术、聚合物电解质制备工艺、新型材料设计进行了评价。综合分析表明,聚合物固态电解质采用低聚物、无机纳米颗粒掺杂、功能分子设计等方法,逐步实现了固态电池的适用温度由90℃向室温、低温的成功转变;凝胶电解质室温电导率较高,有机小分子与聚合物基底之间通过分子间力作用增强钠盐溶剂化作用,成功地与不同正、负极材料搭配,普遍实现了室温凝胶钠离子电池,同时回顾了水凝胶在构建水系钠离子电池中的优势与现阶段的研究不足。最后提出聚合物电解质在钠离子电池中应用的研究报道中需要注意的问题,并且展望了未来材料设计、表征技术的可能发展方向。

Recently,there has been rapid and profound progress with respect to the energy and power density of sodium-ion batteries.However,the conventional liquid organic electrolyte/separator system tends to evaporate and burst into flame,leading to wide concerns about its inherent low safety.To develop sodium ion batteries with high energy density and improved safety,solid electrolytes have gained attention,especially polymer-based electrolytes including solid and gel types.This article begins by reviewing the progress in fundamental mechanism and physical chemistry theoretical models for polymer electrolytes,followed by advancements in both solid and gel polymer electrolyte application in sodium ion batteries along with assessments of various material modification techniques,synthesis procedures,and novel material design.Based on the analysis,polymer electrolyte adopting oligomer,inorganic filler,and molecule design strategies are given for the successful conversion of a solid battery operation temperature from 90°C to room temperature or lower.A gel electrolyte relies on intermolecular forces and renders greater solvation effects for sodium salts,realizing quasi-solid batteries coupled with various electrodes generally at room temperature.In addition,a brief comment on hydrogel electrolytes concerning their great potential in aqueous sodium ion batteries is provided.Finally,an appeal is made concerning critical parameters,including volume and mass,in future reports,as well as a brief outlook concerning possible perspectives considering material design,and an in-situ polymer electrolyte technique in sodium ion batteries is proposed.