Organic acids and their crucial role in establishing a sustainable process route in the recycling of lithium-ion batteries

Far-reaching measures are necessary to achieve the climate targets within the European Green Deal and the Paris Climate Agreement. In addition, the mandatory recycling quotes will be increased in the coming years, therefore improved recovery processes are necessary. However, the environment is polluted by emissions and residues from the recycling processes of industrial materials which influ-ence the climate negatively. So far, the valuable metals from the recycling of lithium-ion batteries such as copper, cobalt and nickel are mainly recovered by hydrometallurgical processes with strong inorganic acids. These chemicals cause high salt loads, toxic by-products and gases (e.g., CO2 or SO2), which pollute the wastewater and result in a significant impact on the environment, as the disposal tends to be problematic. However, the application of organic acids in the leaching process offers a more environmentally friendly and sustainable alternative to satisfy ecological and econom-ic aspects in addition to reach high recovery rates of the valuable metals for end-of-life batteries. An economical portrayal of such a process can be realized with organic acids by adding a suitable oxi-dizing agents or organic reducing agents such as glucose. High recovery rates for lithium, nickel and cobalt can be achieved even at low temperatures in the range of 40–75 °C and moderate leaching durations of 2–4 hours with application of suitable organic acids such as gluconic acid