A flexible Cellulose/Methylcellulose gel polymer electrolyte endowing superior Li+ conducting property for lithium ion battery

Feng Yu; Hongbing Zhang; Lingzhu Zhao; Zhipeng Sun; Yuli Li; Yan Mo; Yong Chen

doi:10.1016/j.carbpol.2020.116622

A flexible Cellulose/Methylcellulose gel polymer electrolyte endowing superior Li⁺ conducting property for lithium ion battery

Carbohydr Polym. 2020 Oct 15:246:116622. doi: 10.1016/j.carbpol.2020.116622. Epub 2020 Jun 12.

Authors

Feng Yu¹, Hongbing Zhang², Lingzhu Zhao², Zhipeng Sun², Yuli Li³, Yan Mo², Yong Chen⁴

Affiliations

¹ State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan Provincial Key Laboratory of Research on Utilization of Si-Zr-Ti Resources, College of Materials Science and Engineering, Hainan University, Renmin Road No.58, Haikou, 570228, PR China; Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), College of Chemistry, Nankai University, Tianjin, 300071, PR China. Electronic address: [email protected].
² State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan Provincial Key Laboratory of Research on Utilization of Si-Zr-Ti Resources, College of Materials Science and Engineering, Hainan University, Renmin Road No.58, Haikou, 570228, PR China.
³ Institution of Plastic Surgery, Weifang Medical University, Weifang, 261042, PR China.
⁴ State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan Provincial Key Laboratory of Research on Utilization of Si-Zr-Ti Resources, College of Materials Science and Engineering, Hainan University, Renmin Road No.58, Haikou, 570228, PR China. Electronic address: [email protected].

PMID: 32747261
DOI: 10.1016/j.carbpol.2020.116622

Abstract

With the advent of gel polymer electrolyte (GPE), a series of safety problems of lithium ion batteries have been resolved. However, poor self-standing property, the low ionic conductivity and Li⁺ transference number are still the obstacles that impede the practical application of GPE. Herein, a flexible and eco-friendly GPE is designed using allyl-modified cellulose with methylcellulose through simple UV curing. The crosslinked structure facilitates the integrity of GPE during use, and methylcellulose guarantees the high affinity to liquid electrolyte and improve interfacial compatibility. The specific polar functional groups (OH, OCH₃ and COC) in GPE cooperate to enhance the lithium salt dissociation, anion immobilization and lithium ion transporting and enable the high Li⁺ transference number (0.902) and ion conductivity (4.36 × 10^-3 S cm^-1). The assembled Li/GPE/LiFePO₄ coin cells possess high initial discharge capacity of 150.6 mA h g^-1 and a high capacity retention of 91.6 % after 100 cycles.

Keywords: Cellulose modification; Cycle performance; Gel polymer electrolyte; Li(+) transference number; Lithium ion battery.