Researchers at UNIST have made a significant breakthrough in lithium-ion battery (LIB) technology by developing an eco-friendly dry electrode manufacturing process.
This new method does not use harmful solvents and boosts battery performance while promoting sustainability.
The research, led by Professor Kyeong-Min Jeong from the School of Energy and Chemical Engineering at UNIST, was published in the July 2024 issue of Chemical Engineering Journal.
Traditional wet-electrode manufacturing methods often result in non-uniform distribution of binders and conductive materials, which can degrade battery performance.
To address this, the research team introduced a novel solvent-free dry electrode process using polytetrafluoroethylene (PTFE) as a binder. This new approach enhances the uniformity and performance of the electrodes.
The dry electrode process involves four stages: granule formation, film formation, rolling, and lamination. The team optimized the process by evaluating the physical, electrical, and electrochemical properties of semi-finished products at each stage.
They found that using a high-extrusion-ratio PTFE binder produced an electrode film with high strength and low energy consumption, leading to improved battery microstructure and power characteristics.
Binders are crucial in LIBs as they connect active materials and electrons. The study revealed that the type and content of PTFE binders significantly impact the performance of dry electrodes.
The researchers identified an optimal formulation of NCM811/PTFE/carbon black (CB)/carbon nanotube (CNT) = 96/2.0/1.8/0.2. This formulation demonstrated an impressive discharge rate capability of 80% at a 0.5 C-rate (5 mA/cm²) under demanding conditions.
“This breakthrough will help with commercialization by providing a scalable and practical solution for mass production,” emphasized Professor Jeong. “We believe our study will lead to environmentally friendly and efficient electrode manufacturing for future energy storage applications.”
In addition to UNIST, the Korea Institute of Energy Research (KIER) and Hanwha Co., Ltd. have partnered to develop dry electrode-specific manufacturing equipment. They plan to demonstrate its commercial viability from the second half of 2024.
The team is also planning to further improve the performance of thick electrodes by exploring various materials through follow-up research. This innovative technology is expected to make electric vehicles and electronic devices more sustainable in the future.
In summary, this new dry electrode process offers a significant advancement in lithium-ion battery technology by eliminating harmful solvents and enhancing performance. With ongoing research and development, this technology holds great promise for the future of energy storage and sustainability.
