(Invited) Achieving Fast and Ultra-Low Binder Dry Electrodes via CNT-Assisted Fibrillation Acceleration Strategy

Dry electrode processing for lithium-ion batteries presents a highly practical approach for fabricating thick electrodes without the use of any solvents, ensuring sustainability while achieving uniform carbon and binder distribution[1]. However, the conventional dry electrode process utilizing PTFE binder faces significant challenges, including increased costs and particle degradation due to the prolonged mixing required during the kneading process, which forms the electrode dough through PTFE binder fibrillation[2]. Additionally, achieving sufficient fibrillation to enhance mechanical integrity often necessitates higher PTFE content, hindering efforts to minimize binder usage [3]. In this study, we introduce a novel strategy to accelerate PTFE fibrillation by enhancing surface roughness, thereby amplifying shear forces during the kneading process. This innovative approach reduces the kneading time by over 75% while maximizing the mechanical properties of the electrode using the same PTFE content. By employing this method, we demonstrate a high-performance dry electrode containing less than 0.4% PTFE binder, achieving a mass loading of 40 mg/cm² with improved electrochemical properties. This work represents a breakthrough in the development of cost-effective, sustainable, and high-performance dry electrode technologies for lithium-ion batteries. [1] Zhang, Ye Shui, et al. "A review of lithium‐ion battery electrode drying: mechanisms and metrology." Advanced Energy Materials 12.2 (2022): 2102233. [2] Kuang, Yudi, et al. "Thick electrode batteries: principles, opportunities, and challenges." Advanced Energy Materials 9.33 (2019): 1901457. [3] Ryu, Minje, et al. "Ultrahigh loading dry-process for solvent-free lithium-ion battery electrode fabrication." Nature communications 14.1 (2023): 1316.