Low‐Cost, High‐Strength Cellulose‐based Quasi‐Solid Polymer Electrolyte for Solid‐State Lithium‐Metal Batteries

• Published in: Angewandte Chemie 2023-06, Vol.135 (25), p.n/a
• Main Authors: Wang, Dai, Xiea, Hui, Liu, Qiang, Mu, Kexin, Song, Zhennuo, Xu, Weijian, Tian, Lei, Zhu, Caizhen, Xu, Jian
• Format: Article
• Language: English
• Subjects: Acetic acid; Capacity Retention; Cellulose acetate; Chemistry; Composite materials; Density functional theory; Electrochemistry; Electrolytes; Esterification; High Ionic Conductivity; Interface stability; Ion currents; Li+ Transference Number; Lithium; Lithium batteries; Low-Cost; Molten salt electrolytes; Polymers; Production costs; Quasi-Solid Polymer Electrolyte; Solid electrolytes
• ISSN: 0044-8249; 1521-3757
• DOI: 10.1002/ange.202302767

Solid‐state lithium‐metal batteries are considered as the next generation of high‐energy‐density batteries. However, their solid electrolytes suffer from low ionic conductivity, poor interface performance, and high production costs, restricting their commercial application. Herein, a low‐cost cellulose acetate‐based quasi‐solid composite polymer electrolyte (C‐CLA QPE) was developed with a high Li+ transference number ( tLi+ ${{t}_{{{\rm L}{\rm i}}^{+}}}$ ) of 0.85 and excellent interface stability. The prepared LiFePO4 (LFP)|C‐CLA QPE|Li batteries exhibited excellent cycle performance with a capacity retention of 97.7 % after 1200 cycles at 1 C and 25 °C. The experimental results and Density Function Theory (DFT) simulation revealed that the partially esterified side groups in the CLA matrix contribute to the migration of Li+ and enhance electrochemical stability. This work provides a promising strategy for fabricating cost‐effective, stable polymer electrolytes for solid‐state lithium batteries. A low‐cost, high‐strength cellulose‐based quasi‐solid polymer electrolyte was developed with high Li+ conductivity, Li+ transference number (0.85) and excellent interface stability. The delicate design results in an unprecedented 1200 cycles with 97.7 % capacity retention at 1 C and 25°C is achieved for the assembled solid‐state batteries, which provides a crucial solution for the industrial production of next‐generation batteries.