Supramolecular Network Structured Gel Polymer Electrolyte with High Ionic Conductivity for Lithium Metal Batteries

• Published in: Small (Weinheim an der Bergstrasse, Germany) Vol. 18; no. 43; pp. e2106352 - n/a
• Main Authors: Chen, Fei, Guo, Changxiang, Zhou, Honghao, Shahzad, Muhammad Wakil, Liu, Terence Xiaoteng, Oleksandr, Sokolskyi, Sun, Jining, Dai, Sheng, Xu, Ben Bin
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.10.2022
• Subjects: Ambient temperature; Discharge; Electrolytes; Electrolytic cells; gel polymer electrolytes (GPEs); High temperature; high‐voltage electrolytes; Hydrogen bonding; Ion currents; ionic conductivity; Ions; Lithium; Lithium batteries; lithium metal batteries; Molten salt electrolytes; Nanotechnology; Photopolymerization; Polymer films; Polymers; Room temperature; Solid electrolytes; supramolecular networks; Tensile strain; Thermal stability; Weight reduction; high-voltage electrolytes; ionic conductivity; gel polymer electrolytes (GPEs); lithium metal batteries; supramolecular networks
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.202106352

Polymer‐based solid electrolytes (PSEs) offer great promise in developing lithium metal batteries due to their attractive features such as safety, light weight, low cost, and high processability. However, a PSE‐based lithium battery usually requires a relatively high temperature (60 °C or above) to complete charge and discharge due to the poor ionic conductivity of PSEs. Herein, a gel polymer electrolytes (GPEs) film with a supramolecular network structure through a facile one‐step photopolymerization is designed and developed. The crosslinked structure and quadruple hydrogen bonding fulfil the GPEs with high thermal stability and good mechanical property with a maximum tensile strain of 48%. The obtained GPEs possess a high ionic conductivity of 3.8 × 10−3 S cm−1 at 25 °C and a decomposition voltage ≥ 4.6 V (vs Li/Li+). The cells assembled with LiFePO4 cathode and Li anode, present an initial discharge specific capacity of 155.6 mAh g−1 and a good cycling efficiency with a capacity retention rate of 81.1% after 100 charges/discharge cycles at 0.1 C at ambient temperature. This work encompasses a route to develop high performance PSEs that can be operated at room temperature for future lithium metal batteries. Gel polymer electrolytes (GPEs) with a supramolecular network structure have a high ionic conductivity (3.8 × 10−3 S cm−1 at 25 °C). In addition, the GPEs has good mechanical properties and can reach a stretch rate of 48%. Lithium metal batteries are capable of high capacity cycling at room temperature.