Electrochemical Re-Functionalization of Spent FePO4 Originating from LiFePO4 Battery Recycling

Lithium-ion batteries (LIBs) find many applications from powering multitudes of portable electronics, to automotive, and stationary energy storage. The current rapid market growth, more specifically in mobility and stationary energy storage, has made the consumption of LIBs to increase exponentially since year 2000. It is predicted that this market will be multiplied by ten in the next decade. Inevitably, the quantity of spent LIBs will follow the same trend, causing important challenges to the waste management system. However, while end-of-life (EOL) management of portable batteries is established in North America and Europe, collection of industrial and vehicle batteries is just starting. Consequently, we expect an important increase of spent lithium battery available for recovery during the next decade raising the pressure on the recycling industry. In addition to the rapid increase in volume of spent batteries, the wide range of chemistries and types make recycling of LIBs more complex compared to other types of batteries. Until now, the industry has focussed on recovering the most valuable metals like cobalt and nickel while sending to the waste elements such as lithium, iron, and phosphorus from lithium iron phosphate (LiFePO4, LFP) batteries. Hydro-Québec has developed a new low environmental footprint process to recover efficiently high value product from spent LiFePO4 batteries. The process includes a dismantling and sorting step from which the active cathodic material is recovered as a black mass. A hydrometallurgical process extracting selectively Li ions as lithium bicarbonate from the black mass follows this preparation stage. The leaching residue is a carbon-coated iron (III) phosphate (FePO4 -C) which is re-functionalized as fully restored cathodic active material by taking advantage of highly reversible lithium intercalation into the FePO4 hosting structure. The final product is suitable for reuse in new LiFePO4 battery manufacturing.