Jump to main content
Jump to site search


Determining the Limiting Factor of the Electrochemical Stability Window for PEO-based Solid Polymer Electrolyte: Main chain or terminal –OH group?

Abstract

Due to higher energy density, high-voltage all-solid-state lithium batteries (ASSLBs) have attracted increasing attention. However, they require solid-state electrolytes (SSEs) with wide electrochemical stability windows (ESW, typically >4.2 V) and high-stability against Li anode. Nevertheless, poly (ethylene oxide) (PEO), the most widely used solid polymer electrolyte (SPE), can’t tolerate a high-voltage over 4 V. Whether the main chain (-C-O-C-) or the terminal hydroxide group (-OH) is the limiting factor for the narrow ESW remains unknown. Herein, poly (ethylene glycol) (PEG) and poly (ethylene glycol) dimethyl ether ‎(PEGDME) with different terminal groups are selected to answer this question. The results show that the reactive terminal –OH group is the limiting factor towards applicability against high-voltage and Li anode. Replacing the –OH with more stable –OCH3 can significantly extend the ESW from 4.05 to 4.3 V, while improving the Li-anode compatibility as well (Li-Li symmetric cells stably run for 2500 h at 0.2 mA cm-2). Its practical application is further proved by developing PEGDME-based ASSLB pouch cells. The 0.53 mA cm-2 Li-LiFePO4 and 0.47 mAh cm-2 Li-LiNi0.5Mn0.3Co0.2O2 cells demonstrated high capacity retention of 97% and 90% after 210 cycles and 110 cycles, respectively. This work offers a new strategy for PEO-based high-voltage ASSLBs development by changing the unstable terminal groups.

Back to tab navigation

Supplementary files

Article information


Submitted
03 Feb 2020
Accepted
26 Mar 2020
First published
26 Mar 2020

Energy Environ. Sci., 2020, Accepted Manuscript
Article type
Communication

Determining the Limiting Factor of the Electrochemical Stability Window for PEO-based Solid Polymer Electrolyte: Main chain or terminal –OH group?

X. Yang, M. Jiang, X. Gao, D. Bao, Q. Sun, N. Holmes, H. Duan, S. Mukherjee, K. Adair, C. Zhao, J. liang, W. Li, J. Li, Y. Liu, H. Huang, L. Zhang, S. Lu, Q. Lu, R. Li, C. V. Singh and X. Sun, Energy Environ. Sci., 2020, Accepted Manuscript , DOI: 10.1039/D0EE00342E

Social activity

Search articles by author

Spotlight

Advertisements