Conference program

November 24, 2011
Session 5
11:00 a.m.

Strategic minerals and metals used in the manufacture of lithium storage cells (accumulators) for electric vehicles
Daniel Perlstein (Anextase)

Even though the NiMH (Nickel Metal Hydride) battery made it possible to launch the first hybrid electric car (the Toyota Prius) in late 1997, automakers currently producing or thinking of producing hybrid and electric cars now appear to have adopted lithium-ion battery technology.

The medium-term demand for the materials needed to manufacture lithium-ion batteries depend on several factors:

• the growth rate for electric vehicle production;
• the growth rate for hybrid vehicle production;
• the types of lithium-ion batteries used, and their cathode active materials in particular (manganese oxides, or nickel-cobalt-manganese oxides, or metallic phosphates, or others).

It will be important to distinguish the future of fully electric vehicles from that of hybrid vehicles, and in the case of the hybrid, it will also be important which type of hybrid becomes predominant since battery size (in kWh) and the amount of active materials can vary considerably. For example, the battery size for the “mild” Toyota Prius hybrid is 1.8 kWh, whereas the battery for the “plug-in” Chevrolet Volt is 16 kWh, and for the fully electric Nissan Leaf it is 24 kWh.

It is also important to link the future of electric vehicle batteries to the outlook for batteries used for storing electrical energy because both sectors use the same battery technology.

The lithium-bearing material needed to manufacture batteries will essentially be lithium carbonate, a material that is already used in a variety of processes to make lithiated metal oxides or lithiated metal phosphates, and sometimes lithium metal anodes.

The base material for the anode will be graphite, but silicon- or tin-based alternatives are beginning to emerge.

The electrode material must be as pure as possible with a composition that does not change over time. Two main types of processes exist for producing cathode materials: thermal solid state and hydrothermal processes. Each has its own advantages and drawbacks due to the size of the particles produced and their properties at the nanometre scale. In the case of lithiated iron phosphate (LiFePO₄), Phostech Lithium will use both types of processes in Québec but at two separate production units.