Similarly, different batteries involve different material compositions, that require the extraction of specific elements. These factors lead to difficulties in recycling and require a number of experimental steps to get the right composition . The most discussed example is the recycling of black mass, which is a mixture of the active material powders of both electrodes, which is very complicated to either separate or regenerate directly. This challenge is intensified in the case where the transition metals are sensitive to reduction by carbon if a heating stage is required .