Worldwide consumption of electronic devices has led to a sharp increase in waste batteries. Spent lithium-ion batteries (LIBs) contain critical elements, such as lithium (5-8 per cent); cobalt (5–20 per cent); nickel (5–10 per cent), and manganese (10–15 per cent). Nickel–metal hydride batteries also possess a high content of nickel (36–42 per cent) and cobalt (3–5 per cent).
Future demand for such critical elements, especially cobalt and nickel, has been predicted to exceed identified reserves and there are increasing geographical, environmental and political pressures related to primary mining operations. This means there is urgent pressure to develop sustainable strategies to recover critical elements from the potentially valuable secondary resources.
However, it is difficult to separate the valuable metals inside spent lithium-ion batteries from each other for recycling purposes and current methods used for their separation have environmental and...