Lithium ion batteries (LIB) are the best way we have of storing and using portable electrical energy. This technology is constantly evolving and as it does demand will only increase. This ability to store and discharge energy has put LIB’s in a great position to be a transitional technology to wean us off of fossil fuel based energy production. In order to be able to continue and increase manufacturing capacity we must recycle the existing stock of batteries in order to supplement the mining of these minerals that make up the active material of the cells.
This project is a preliminary design of a battery recycling plant that would be able to operate on a flexible feedstock of batteries from consumer electronics and also batteries from existing electric vehicles. These batteries have different chemistries but due to the design of the plant and the batch process they may be processed in the same facility with minimal downtime between batches.
The plant itself would consist of three main unit operations: heat treatment, leaching and precipitation. In the heat treatment area there will be two furnaces, one for de-energizing the cells and collecting the electrolyte solution and one for the reduction roasting process to enable the leaching and separation steps. Between these steps they will be ground to small pieces to increase the surface area for the leaching process. The ground and roasted batteries will be leached first with water to collect the lithium carbonate and then again with sulphuric acid to collect the rest of the target metals (Ni, Co, Mn). This solution will be treated to a three step precipitation process which will separate the remaining target metals from each other. At this point the product streams will be in a state to be used as raw materials in new Lithium ion cells.
Global supplies of rare earth minerals will be unpredictable in the future and a robust recycling infrastructure will do much to stabilize prices and ensure supply while enabling a smooth transition to a greener energy system.
