Microfibril Aramid-Nanocellulose Fiber-Based Hybrid Separator for High-Performance Lithium-Ion Batteries

• Published in: Journal of the Electrochemical Society 2023-02, Vol.170 (2), p.20519
• Main Authors: Yang, Runjie, Wu, Zegang, Lu, Tingting, Yu, Guoqing, Liu, Fengqin, Hu, Tao, Zhao, Hongliang
• Format: Article
• Language: English
• Subjects: aramid fiber; cellulose; lithium-ion batteries; separator; thermal stability
• ISSN: 0013-4651; 1945-7111
• DOI: 10.1149/1945-7111/acb8e6

The poor thermal stability and wettability of commercial polyolefin separators are safety hazards that limit the electrochemical performance of lithium-ion batteries (LIBs). In this work, a novel aramid-nanocellulose fiber-based hybrid separator (Aramid-NCF separator) was fabricated by an industrial one-step paper-making process. The separator showed excellent heat stability, suitable pore structure, and outstanding electrolyte wettability, with a contact angle close to 0°. The Aramid-NCF separator showed superior ionic conductivity of 5.491 × 10 −4 S·cm −1 compared with an alumina-coated PE separator (PE-Al 2 O 3 separator) (3.260 × 10 −4 S·cm −1 ). LIBs with the Aramid-NCF separator also showed better C-rate performance, better cycling performance, and a higher capacity retention rate than batteries prepared with the PE-Al 2 O 3 separator. A pouch battery with the Aramid-NCF showed a higher capacity retention rate (89.17% after 200 cycles at 0.5 C) than a pouch battery with the PE-Al 2 O 3 separator (86.01% after 200 cycles at 0.5 C). Therefore, the Aramid-NCF separator is a promising candidate for next-generation LIBs.