Ion‐Conducting Molecular‐Grafted Sustainable Cellulose Quasi‐Solid Composite Electrolyte for High Stability Solid‐State Lithium‐Metal Batteries

• Published in: Advanced functional materials 2024-09, Vol.34 (37), p.n/a
• Main Authors: Wang, Ruixue, Dong, Weiliang, Song, Zhennuo, Tan, Jiji, Liu, Qiang, Mu, Kexin, Xu, Weijian, Huang, Haiyu, Zhang, Zhili, Yin, Gang, Zhu, Caizhen, Xu, Jian, Tian, Lei
• Format: Article
• Language: English
• Subjects: Battery cycles; Bonding strength; Cellulose acetate; Chemical bonds; Conduction; Electrolytes; Grafting; high ionic conductivity; high stability; Hydrogen bonds; Interfacial properties; Ion currents; Ion transport; Lithium; Lithium batteries; Molecular chains; molecular grafting; Room temperature; Solid electrolytes; solid‐state lithium‐metal batteries; Stability; sustainable cellulose
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.202402461

Cellulose‐based solid electrolyte possesses the characteristics of low cost, high strength, and sustainability, and has great potential in the field of solid‐state lithium metal batteries. However, the large hydrogen bonds between cellulose molecules make the molecular chains tightly arranged, and hinder the ion conduction, seriously limiting its further development. Herein, an ion‐conducting molecular grafting strategy is proposed for the fabrication of cellulose acetate quasi‐solid composite electrolyte (CLA‐CN‐LATP QCE) with a superior ionic conductivity of 1.25 × 10−3 S cm−1 at room temperature. Benefited from grafted functional molecules, the assembled symmetrical battery exhibits low polarization voltage and highly stable lithium stripping/plating cycling of more than 1200 h at 0.1 mA cm−2 current density. Moreover, it endows LFP|CLA‐CN‐LATP QCE|Li battery with excellent long‐cycle stability of 1500 cycles at 0.5 C and 25 °C and superior capacity retention of 92.1%. Importantly, this work provides an effective strategy for further opening the ion transport channel between cellulose molecular chains and improving the interface properties of electrolytes and electrodes. An ion‐conducting molecular grafting strategy is reported to break the cellulose molecular chain, further build the lithium‐ion transport channel, and improve interface performance. Thus quasi‐solid electrolyte exhibits superior ionic conductivity of 1.25 × 10−3 S cm−1 (25 °C), and excellent cycle stability at 0.5 C and 25 °C for 1000 cycles with a high capacity retention rate of 95.2%.