Phosphoric Acid Leaching of Valuable Metals from Spent Cathode Materials Using the Doehlert Model: A Sustainable Approach to Enhancing Resource Recovery Through Advanced Experimental Techniques

Abstract

The increasing demand for lithium-ion batteries, driven by their exceptional electrochemical performance, has led to significant market expansion in recent years. However, the limited availability of critical metals required for battery production poses a challenge to sustaining this demand. As a result, recycling has emerged as a viable and cost-effective solution. This study investigates the impact of various factors on metal recovery through phosphoric acid leaching, including time, solid/liquid ratio, temperature, acid concentration, and the presence of hydrogen peroxide. It was demonstrated that under optimal conditions using a 20 g/L solid/liquid ratio, 4 M acid concentration, 2 vol% hydrogen peroxide, and a temperature of 60°C for 60 minutes, over 99% of Mn, Ni, Co, and Li can be successfully recovered. This process not only contributes to environmental sustainability by reducing the disposal of spent lithium-ion batteries but also provides an alternative source of critical metals for the growing lithium-ion battery market.