Sustainable recycling of Li-ion batteries

Abstract: Lithium-ion batteries (LIBs) play a key role in today’s energy storage sector, finding applications in everyday use electronic devices, like smartphones, laptops or electric vehicles. Despite very good properties, such as high electric capacity and high number of charge-discharge cycles, eventually each battery in the world will be disposed and stored in a landfill, waiting for the opportunity to be recycled. Until then, spent LIBs are a serious hazard to the natural environment because of their toxic constituents, like organic electrolytes or transition metal based electrodes, and unfortunately, the majority of those used batteries will never be recycled due to a lack of profitable and sustainable methods for the recovery of battery components.The demand for the production of new batteries is caused by the increase in the number of electronic devices being sold to end customers every year, and battery waste is an important and promising source of valuable metals, so far essential for manufacturing new electrode materials. However, the existing industrial methods for the recovery of metals from batteries, despite high yields and purity of obtained products, usually are associated with high energy demand, implementation or in situ generation of toxic chemicals, and generation of additional, non-recyclable fractions – therefore they can not be considered as sustainable.This thesis summarizes the approaches taken during Author’s doctoral studies towards green LIBs recycling, implementing various techniques, like adsorption and electrochemistry, as well as the valorisation of spent LIBs towards environmental applications. The first and second works implement adsorption for the recovery of metal ions present in the battery cathode materials from aqueous solutions. The third work implements the production of a cobalt catalysts made from scrap LIBs cathode materials with further testing towards hydrogen evolution reaction from sodium borohydride. The fourth work implements hydrometallurgical treatment of spent LIBs cathode materials via leaching and electrochemical separation of metals. The aim is to show the possibilities for the recovery and reuse of spent battery cathode materials, as well as the environmental importance of recycling.