Microalgae in the recycling of used batteries: a path towards sustainable ecology

With the increase in demand for electric vehicles new challenges have arisen. In particular, the proper disposal of used batteries, something that poses a serious environmental threat. Although recycling heavy metals such as lithiumhe cobaltmanganese, nickel and others found in batteries is the preferred approach, the extraction process often causes environmental contamination. At present, the lack of advanced technology makes the recycling be more expensive than disposal.

However, one company has successfully tackled this formidable challenge. Green Mineral Inc. is pioneering an innovative technology that harnesses the power of microalgae to extract lithium from used batteries, marking an important global milestone. Jung Kwang-Hwan, a representative of Green Mineral, was interviewed at his research laboratory at Sogang University, Mapo-gu, Seoul, on the afternoon of the 30th of last month.

Jung noted: “Unlike conventional chemical methods that rely on organic solvents for the recycling of batteries, our environmentally friendly approach offers ecological benefits, while being economically viable.” He described this as a “paradigm shift in the field of used battery recycling”.

As a professor at Sogang University’s Department of Biological Sciences, Jung initially conducted research on the use of microalgae to remove radiation-emitting substances. Over a decade ago, he made a significant discovery regarding the applicability of this technology for the extraction of lithium from used batteries.

The presence of chlorella, a type of microalgae, caught his attention. Chlorella, recognized as a functional food, has the unique ability to convert metal ions such as lithium into carbonates.

“It operates on a principle similar to the shellfish process in creating shells”Jung explained. “When calcium enters the cell membrane of shellfish and reacts with carbon dioxide, it undergoes a transformation into calcium carbonate. calcium, solidifies and is released. Similarly, chlorella shows a similar reaction with lithium that leads to biomineralization, in which cells form minerals.”

The most significant benefit of chlorella is its environmentally friendly nature. The typical method of recycling used batteries consists of a chemical treatment in which a black powder is processed to extract metals such as cobalt, nickel, manganese, etc. Wastewater, dissolved in sulfuric acid and other substances, lacks a viable method of recycling and is mostly disposed of.

Recycling batteries incurs higher costs compared to discarding them. However, using chlorella, lithium can even be extracted from wastewater. Additionally, chlorella absorbs carbon dioxide, which contributes to carbon neutrality.

Representative Jung embarked on a world tour to acquire chlorella. During this trip, he successfully developed a new strain of chlorella through genetic manipulation, which demonstrated improved metal extraction capabilities.

His goal was to increase lithium production and improve the cultivation of chlorella in large quantities. Thanks to this, Green Mineral can now recover 20kg of 28kg of lithium from batteries used in electric vehicles. The use of chlorella for lithium extraction is cost-effective as it is more affordable than organic solvents, making it an economically viable solution. This lithium extraction method is recognized as the only one that is both economical and environmentally friendly.

Currently, Green Mineral is processing patent applications in several countries and regions, including Korea, the United States, the European Union, Japan, and China. The objective is to secure a share of the world market for recycled lithium greater than 30%. Jung stresses: “There seems to be a prejudice that being environmentally friendly lacks economic viability in business. However, good technology must encompass both environmental sustainability and economic viability. That is the fundamental principle of ESG criteria. Our goal is to revitalize society, the environment and business through environmentally friendly battery recycling technology.”

Source: AP