Page 112 - Read Online

Cui et al. Energy Mater 2023;3:300034 Energy Materials
DOI: 10.20517/energymater.2023.19

Article Open Access

Achieving fast and stable Li transport in lithium-
+
sulfur battery via a high ionic conduction and high
adhesion solid polymer electrolyte

Ximing Cui, Xiaohui Wang, Qinmin Pan *

School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, Heilongjiang, China.
*Correspondence to: Prof. Qinmin Pan, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, No. 92,
Xidazhi Street, Nangang District, Harbin 150001, Heilongjiang, China. E-mail: panqm@hit.edu.cn
+
How to cite this article: Cui X, Wang X, Pan Q. Achieving fast and stable Li transport in lithium-sulfur battery via a high ionic
conduction and high adhesion solid polymer electrolyte. Energy Mater 2023;3:300034.
https://dx.doi.org/10.20517/energymater.2023.19

Received: 24 Mar 2023 First Decision: 25 Apr 2023 Revised: 16 May 2023 Accepted: 25 May 2023 Published: 6 Jul 2023
Academic Editors: Elie Paillard, Xiongwei Wu Copy Editor: Fangling Lan Production Editor: Fangling Lan

Abstract
Solid-state lithium (Li)-sulfur (S) batteries are promising secondary batteries because of their high energy density
+
and high safety, but their practical application is severely hindered by poor Li-ions (Li ) transport in batteries due to
low ionic conduction of the electrolyte and unstable electrode/electrolyte interface. Here, we address the issue by
using a polyurethane (PU)-based electrolyte. The polar urethane/urea groups of PU reduce the hopping energy
-4
-1
+
barrier of Li , which results in high ionic conductivity of 1.8 × 10 S cm (25 °C), high ion transference number of
0.54, and low activation energy of 0.39 eV. In addition, the polar urethane/urea groups endow the electrolyte with
high adhesion, which allows the electrode/electrolyte interfaces to self-heal timely after being damaged during
c y c l i n g . B e n e f i t i n g f r o m t h e s e m e r i t s , a s y m m e t r i c L i | | L i c e l l u s i n g t h e p o l y o l e f i n - P U -
bis(trifluoromethane)sulfonimide lithium salt electrolyte can cycle for approximately 800 h with a stable
overpotential (approximately 40 mV), and a solid-state Li-S battery using the electrolyte delivers a specific
-2
-1
capacity of approximately 610 mAh g after testing for 125 cycles at a S loading of about 4 mg cm . Self-healing of
the electrode/electrolyte interfaces during cycling was observed in situ by a laser confocal microscope. This study
+
demonstrates the importance of polar groups in electrolytes in maintaining a fast and stable Li transport, which
can be applied to other solid-state batteries.
Keywords: Solid-state Li-S battery, urethane/urea groups, low energy barrier, self-healing electrode/electrolyte
interface, in-situ observation

© The Author(s) 2023. Open Access This article is licensed under a Creative Commons Attribution 4.0
International License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, sharing,
adaptation, distribution and reproduction in any medium or format, for any purpose, even commercially, as
long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and
indicate if changes were made.

www.energymaterj.com