Dry Electrode Manufacturing Technology: The "Rising Star" of the Battery

Tesla's 4680 large cylindrical battery cell is truly eye-catching, especially with its dry powder electrode manufacturing technology. Compared to traditional liquid lithium-ion battery electrode manufacturing techniques, this technology has obvious advantages, and it’s no wonder it has attracted so much interest from equipment suppliers and battery companies.

In fact, dry powder manufacturing technology appeared as early as the 1960s in the production of nickel-cadmium batteries, but it didn't attract much attention at that time. Tesla utilized this dry method technique for producing electrode sheets by acquiring the American supercapacitor company Maxwell, and then applied it to the manufacturing of the 4680 electrodes. However, there are still many hurdles to overcome with this technology. It is said that the dry method for the positive electrode of the 4680 has not been fully implemented, leading to high production costs for the cells that affect the competitiveness of the entire vehicle. Consequently, the technical leader responsible eventually left Tesla.
What is dry method electrode manufacturing technology?

Dry method electrode manufacturing technology refers to the process of mixing powdery active substances, conductive agents, and minimal or no binders through physical or chemical methods and forming them into self-supporting or non-self-supporting films, which are used as positive electrodes, negative electrodes, or solid-state electrolytes for lithium-ion batteries.

Advantages of dry method electrode manufacturing technology

Improve electrode uniformity: Dry method electrode technology does not use solvents in the mixing process, allowing for uniform mixing of the components in the electrode material and avoiding electrode layering caused by solvent evaporation.

Increase active material loading: The dry method allows ease in controlling electrode thickness and uniformity of thick electrodes, providing unique advantages for preparing high-load electrodes.

A good method for preparing sulfide solid-state electrolytes: The dry method does not use organic or polar solvents and requires only minimal binders, making it very suitable for preparing sulfide all-solid-state battery electrolyte films, which have high ionic conductivity.

Significantly lower manufacturing costs: Since the dry method does not use organic solvents, equipment for solvent use and recovery, as well as electrode sheet drying machinery, can be saved, greatly reducing fixed asset investment and manufacturing costs.

Two methods of dry method electrode manufacturing

Powder extrusion forming method: Achieves binder fibrillation during the powder mixing process to form a self-supporting dry electrode film.

Electrostatic spraying method: Uses electrostatic spraying equipment to uniformly adsorb completely dry electrode materials, binders, and conductive agents onto the current collector, followed by subsequent rolling processes to prepare the dry method electrode.
Undoubtedly, dry method electrode manufacturing technology is a "new star" in the battery industry. Although there are still some technical challenges to overcome, its advantages and potential are enormous. In the future, we may see more news and progress related to dry method electrodes.