English
The growing use of electric vehicles and portable electronics has significantly increased the demand for lithium-ion batteries (LIBs). End-of-life LIBs are processed into a material known as ‘black powder’, which contains valuable metals such as lithium (Li), cobalt (Co), nickel (Ni), and manganese (Mn). This black powder serves as a primary feedstock for recovering these critical metals. Traditionally, pyrometallurgy and strong acid-based hydrometallurgy have been applied for the chemical leaching of black powder. However, these conventional methods are either energy-intensive or raise significant environmental concerns.
In this context, this study aims to suggest an eco-friendly alternative by applying fungal bioleaching as a sustainable method for recovering valuable metals from black powder. The freshwater fungal species were utilized in bioleaching process due to their decreasing effects on pH with organic acid production. First, fungal strains were screened based on their ability to lower the pH of the medium, indicating the production of organic acids such as citric acid, oxalic acid, and malic acid. Based on the pH-based screening, fungal species were selected. The pH values dropped below 2 in both malt extract broth (MEB) and potato dextrose broth (PDB). Thus, these strains are expected to increase the metal leaching efficiency for black powder via acidic dissolution. Future work will apply these fungi to actual black powder samples and investigate optimal leaching conditions, with the goal of establishing a scalable and sustainable bioleaching strategy.
