Biological recovery of critical metals from spent lithium-ion batteries using an innovative combination of the extremophilic bacteria (Acidithiobacillus thiooxidans) and red microalgae (Cyanidioschyzon merolae)

A key element of circular economy systems is sustainable raw materials management. Technological progress is constantly reducing natural resources, which in the near future may result in their complete depletion. The answer to this critical condition is the recovery of waste components. Particularly valuable are metals contained in polymetallic waste, an example of which are spent lithium-ion batteries used in small- size electronic devices and the automotive industry - hybrid and electric vehicles. Although metallic raw materials from waste batteries are already recovered on an industrial scale, in the context of the ongoing climate and energy transformation, new, less environmentally impactful, yet effective and economical methods of recycling this type of waste are constantly sought. An alternative may be bioleaching using the natural ability of microorganisms to recover metals, which is pivotal for the next generations of eco processes. The article presents a two-step biological method of cobalt, copper, lithium, and nickel recovery from spent lithium-ion batteries with a combination of extremophilic bacteria (Acidithiobacillus thiooxidans) and red microalgae (Cyanidioschyzon merolae) used in this context for the first time. It has been shown that it is possible to effectively extract metals, especially lithium and nickel (86.22%, 49.50%) from the electrode powder of spent Li-ion batteries at a pulp density of 2% during 10 days of extraction, and bioleaching can be an ecological alternative to currently used methods of industrial recycling of polymetallic waste.

Narodowe Centrum Nauki (NCN), Miniatura 6, 2022/06/X/ST10/00230