Recovery of Li(2)CO(3) from Spent LiFePO(4) by Using a Novel Impurity Elimination Process

The large-scale implementations of lithium iron phosphate (LFP) batteries for energy storage systems have been gaining attention around the world due to their quality of high technological maturity and flexible configuration. Unfortunately, the exponential production of LFP batteries is accompanied by an annual accumulation of spent batteries and a premature consumption of the lithium resource. Recycling souring critical battery materials such as Li(2)CO(3) is essential to reduce the supply chain risk and achieve net carbon neutrality goals. During the recovery of Li(2)CO(3), impurity removal is the most crucial step in the hydrometallurgy process of spent LiFePO(4), which determines the purity of Li(2)CO(3). By investigating and comparing the results of impurity elimination from the purified Li(+)-containing liquids with strong and weak alkalis under identical pH conditions, respectively, a strategy based on an alkali mixture has been proposed. The purified Li(+)-containing liquid was, thereafter, concentrated and sodium carbonate was added in order to precipitate Li(2)CO(3). As a result, a high purity Li(2)CO(3) (99.51%) of battery grade was obtained. LiFePO(4) prepared with the recovered Li(2)CO(3) and FePO(4) as raw materials also displayed a comparative high capacity and stable cycle performance to the commercial product and further verified the electrochemical activity of the recovered materials.