Spray drying tech used in instant coffee applied to high-capacity battery production

The Korea Electrotechnology Analysis Institute (KERI) and the Korea Institute of Supplies Science (KIMS) have collectively developed spray drying technology-based high-performance dry electrode manufacturing expertise for the conclusion of high-capacity secondary batteries. The research is published within the Chemical Engineering Journal.

Secondary battery electrodes are made by mixing energetic supplies that retailer electrical vitality, conductive components that assist the circulate of electrical energy, and binders which act as a type of adhesive. There are two strategies for mixing these supplies: the moist course of, which makes use of solvents, and the dry course of, which mixes strong powders with out solvents.

The dry course of is taken into account extra environmentally pleasant than the moist course of and has gained important consideration as a expertise that may improve the vitality density of secondary batteries. Nonetheless, till now, there have been many limitations to attaining a uniform combination of energetic supplies, conductive components, and binders within the dry course of.

To unravel this drawback, KERI and KIMS utilized the spray drying expertise, which has already been confirmed for mass production within the meals and pharmaceutical industries, to the dry course of. First, the researchers at KIMS blended the energetic supplies and conductive components in a liquid slurry type after which sprayed them right into a high-temperature chamber product of glass tubes.

The precept is that the solvent evaporates immediately because of the excessive temperature contained in the chamber, leaving solely a uniformly blended composite powder of energetic supplies and conductive components. This technique is similar course of used within the mass manufacturing of on the spot stick espresso, the place espresso focus is sprayed and scorching air is utilized to provide strong powder.

The composite powder of energetic supplies and conductive components made utilizing the spray drying approach was remodeled into high-capacity electrodes by the researchers at KERI, who possess in depth know-how and experience in dry-electrode processes. The researchers blended the composite of energetic supplies and conductive components with binders, then carried out a course of referred to as fibrillation, during which the binders are stretched into threads utilizing specifically designed tools.

By this delicate course of, the energetic materials-conductive additives-binders had been higher woven collectively as a construction and may very well be exactly mixed. Lastly, the researchers went by way of a calendering course of, the place the mixed energetic supplies, conductive components, and binders had been made into a skinny movie with uniform density, in the end producing electrodes for batteries.

KERI and KIMS imagine that this achievement will notice excessive capability in secondary batteries. Because of this, it turns into doable to realize optimum mixing between the inner supplies of the secondary battery, decreasing the quantity of conductive components in comparison with earlier than, and as a substitute filling that area with energetic supplies, that are instantly associated to battery capability.

The researchers who performed the joint research drastically diminished the quantity of conductive components from the two–5% vary reported in present dry electrode-related literature to as little as 0.1%, by way of quite a few experiments. In addition they efficiently achieved a world-leading degree of 98% for the content material of energetic supplies.

As well as, the dry electrodes manufactured utilizing this technique achieved an areal capability of roughly 7 mAh/cm²which is double that of business electrodes (2–4 mAh/cm²). The associated analysis outcomes had been acknowledged for his or her excessive technological experience.

Senior Researcher Insung Hwang from KERI’s Subsequent Technology Battery Analysis Middle defined the importance of the analysis outcomes, stating that the optimum mixture of electrode supplies can improve vitality density and efficiency, and that this expertise has nice potential as it may be utilized to next-generation battery fields similar to solid-state batteries and lithium-sulfur batteries.

Senior Researcher Jihee Yoon from KIMS’ Convergence and Composite Supplies Analysis Division said, “Through follow-up research, we plan to reduce process costs, improve mass production capabilities, and increase technology maturity, with the goal of eventually transferring the technology to companies.”