储能科学与技术 ›› 2022, Vol. 11 ›› Issue (6): 1788-1805.doi: 10.19799/j.cnki.2095-4239.2022.0168

• 化工与储能专刊 • 上一篇    下一篇

固态锂电池聚合物电解质研究进展

周伟东(), 黄秋, 谢晓新, 陈科君, 李薇, 邱介山()   

  1. 北京化工大学化学工程学院,北京 100029
  • 收稿日期:2022-03-29 修回日期:2022-05-11 出版日期:2022-06-05 发布日期:2022-06-13
  • 通讯作者: 邱介山 E-mail:zhouwd@mail.buct.edu.cn;qiujs@mail.buct.edu.cn
  • 作者简介:周伟东(1981—),男,教授,研究方向为固态电池,E-mail:zhouwd@mail.buct.edu.cn
  • 基金资助:
    国家自然科学基金面上项目(21875016)

Research progress of polymer electrolyte for solid state lithium batteries

ZHOU Weidong(), HUANG Qiu, XIE Xiaoxin, CHEN Kejun, LI Wei, QIU Jieshan()   

  1. College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
  • Received:2022-03-29 Revised:2022-05-11 Online:2022-06-05 Published:2022-06-13
  • Contact: QIU Jieshan E-mail:zhouwd@mail.buct.edu.cn;qiujs@mail.buct.edu.cn

摘要:

目前锂离子电池的关键挑战是如何提高电池的能量密度和电池的安全性,使用固态电解质的固态锂电池可以有效地缓解这两个问题。固态电解质是固态电池发展的关键材料。固态聚合物电解质(solid-state-polymer electrolyte,SPE)具有较高的柔韧性、优良的加工性和良好的界面接触性,是固态锂金属电池理想的电解质材料。SPE的离子导电性、电化学窗口以及与电极之间界面的稳定性对固态锂电池的综合性能起着至关重要的作用。根据电化学稳定窗口的不同,本文主要综述了:①低电压稳定SPE,与锂金属具有良好的相容性,通过交联、共混、共聚以及与无机填料复合的方法可以有效降低其结晶度,提升聚合物离子电导率;②高电压稳定SPE体系,能够匹配高电压正极使用,有效提高锂金属电池的能量密度;③多层结构SPE体系,能够同时承受锂金属负极的还原和高电压正极的氧化,为进一步开发高性能SPE和提高电池能量密度提供了新思路。最后,对三种SPE体系进行了总结和展望,指出低电压稳定SPE的研究重点在于提高离子电导率以及力学性能,高电压稳定SPE的关键在于降低材料的最高占据分子轨道(highest occupied molecular orbital,HOMO)以及建立正极界面处稳定的CEI层,多层SPE的研究重点在于合适的电池和电极结构设计。构建可与正、负极同时稳定或者同时形成界面钝化层的高导离子聚合物结构是未来的研究重点之一。

关键词: 全固态锂电池, 聚合物电解质, 电化学窗口, 多层聚合物电解质

Abstract:

Currently, the critical challenges of lithium-ion batteries are how to improve their energy density and safety. With the help of nonflammable solid electrolytes and improved compatibility with Li-metal-based anode, solid state lithium batteries can effectively alleviate these two issues. Solid polymer electrolyte (SPE) is one of the most promising solid-state-electrolytes because of its high flexibility, ease of processing, and good interfacial contact. The ionic conductivity, electrochemical window, and electrode stability all play important roles in the overall performance of solid lithium metal batteries. According to the different electrochemical stability windows, this study reviews the typical SPE systems classified by low-and high-voltage stable SPEs. The strategies of chemical modification, electrode/electrolyte interface engineering, and multilayer structure design are discussed, aiming to improve the ionic conductivity and broaden the electrochemical window of SPEs. This review summarizes the different electrochemical stability windows: ① Low-voltage-stable SPEs with good lithium metal compatibility and Li+ conductivity that can be improved by crosslinking, blending, copolymerization, and being composites with inorganic fillers; ② High-voltage-stable SPEs with lower highest occupied molecular orbital (HOMO) energy and match high voltage cathode for improving the energy density of lithium metal batteries; and ③ Multilayer SPE systems that can withstand the simultaneous reduction of lithium metal anode and oxidation of high voltage cathode, providing a new strategy for the development of high energy density batteries. These SPE systems summarize the research focus of low-voltage-stable SPE to improve ionic conductivity and mechanical properties. The key to high-voltage-stable SPE is to reduce the HOMO energy and/or establish a stable CEI layer with a cathode. The research focus of multilayer SPE is the appropriate design of battery and electrode structure. The construction of highly Li-conducting polymer structures, which can stabilize or form an interface passivating layer with both cathode and anode simultaneously, is a future research focus.

Key words: all-solid-state lithium batteries, solid-state polymer electrolytes, electrochemical window, multi-layer polymer electrolytes

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