Energy Storage Science and Technology ›› 2022, Vol. 11 ›› Issue (6): 1788-1805.doi: 10.19799/j.cnki.2095-4239.2022.0168

Previous Articles     Next Articles

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

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

CLC Number: