Lithium Battery Recycling Processes

Extract

[...] Figure 3 : principle scheme of hydrometallurgy Hydrometallurgical treatment allows the valorization of zinc, nickel, cobalt, lithium, and manganese. Today, most of the batteries recycled in Europe are recycled by the Belgian company Umicore through pyrometallurgy, while North American batteries are recycled by the company Kinsbursky Brothers Inc (KBI). The Mineta National Transit Research Consortium report established that the recovery of individual components of Li-ion batteries will not be profitable until 2035 in the United States. It recommends alternative solutions such as battery refurbishment and reuse. [...]

[...] After a description of the operating principle of the lithium accumulator, I will detail the chemical recycling methods of rechargeable lithium batteries, the most widespread in the automotive industry. 1. The electrochemical reaction Batteries store chemically the energy and return it electrically. Batteries work on the basis of a reversible electrochemical system. The movement of electrons produces current between 2 electrodes : - an electrode + that releases or captures electrons, - an electrode - that does the same thing. (Figure 1). The movement of electrons from one to the other through a conductor feeding a receiver creates the current. [...]

[...] Figure 1 : operation of a lithium battery During discharge, there is reduction of the positive electrode and oxidation of the negative electrode. During charging, the reactions are reversed. The cathode is the site of reduction, the anode, that of oxidation. During discharge, the cathode is the positive electrode while it transforms into anode during charging. A lithium battery is characterized by 2 redox couples Carbon/Cobalt Lithium Oxide exchanging electrons. The initial entity of a battery is the result of the association of 2 plates (or 2 insertion materials for the Li-ion battery). [...]

[...] Recycling processes There are two major types of processes for lithium battery and accumulator treatment: pyrometallurgy and hydrometallurgy. a. Pyrometallurgy The accumulators are introduced into a melting furnace. The separation of metals is achieved by an oxidation-reduction reaction: Figure 2 : flowchart of the recycling operations of Li-ion (and NIMH) batteries at Umicore. This process creates residues containing rare earths, aluminium, calcium, lithium and manganese and cobalt, copper, iron, nickel and zinc alloys. Hydrometallurgy allows the recovery of copper, then zinc, iron, cobalt and nickel. [...]