Graphite supply critical to the development of the automotive industry
Many graphite junior mining companies have been stating that they are going to be selling graphite for the battery application, specifically into electric cars. This quick report is to show the approximate magnitude of this market. The public focus has been on Tesla Motors Inc. and their plans for a giga factory that is projected to have the capacity to produce half a million electric cars per year. This is only part of the story. A total annual worldwide production of approximately six million electric cars is commonly projected by the year by 2020. Note: this projection only includes full electric vehicles and doesn’t include hybrids, or any other use of lithium ion batteries.
As a first approximation there will be about 265 kg of graphite per car. As there are 6 carbon atoms required to store one proton, 0.00107 grams of carbon is required for each watt assuming a 50% efficiency of storage and 1.5V battery cells. The 85 kWhr battery in the Tesla model S would then require an estimated 327 kg of graphite. The range of the car is about 450 km, meaning that 0.77 kg of graphite is required per km of range. The power required can be assumed proportional to the mass of the vehicle when equivalent rolling and air resistances are assumed. The Tesla model S has a mass of 2112 kg. Thus, 0.364 grams of graphite is required per (kg*km). What is does number mean? Multiply this number by a car weight (kg) and range (km) and you get the approximate amount of graphite that is required in the car’s batteries. If you assume the average mass of car, which in 2010 was 1,818 kg, and a range of 400 km, then the average car requires 265 kg of graphite.
The amount of graphite required for annual car production can be estimated using the average mass of graphite per car and a projection of the number of cars manufactured. This is shown in Table 1.
Table 1: Estimated electric car graphite consumption. Assumes an average range of 400 km, vehicle mass of 1,818 kg and battery specific graphite of 0.364 g/(kg*km) resulting in an average of 265 kg per vehicle.
The projected number of electric cars sold per year in 2020 is about six million. That is 1.59 million tonnes of graphite. Where is all this graphite going to come from? The differential, or the amount of graphite demand increase each year indicates that one, or more, 100,000 tonne per year mines could open each year solely dedicated to electric cars and this market would not be filled.
Get our daily investorintel update
The graphite will be artificial, natural graphite flakes or natural graphite that has been “balled”. The choice will be economic subject to availability. It is likely, that as long as the quality can be met, the supply will be natural, followed by ball graphite with the remainder being artificial. The economic reason for this is shown in Table 2.
How does this affect the graphite mining industry? The use of natural graphite in these batteries is almost an economic necessity in order to make the vehicles available at a reasonable cost. The total amount of natural graphite currently produced that is applicable to batteries is approximately 50,000 tonnes and this source is shared with cell phones, tablets and laptops. The exact amount doesn’t matter; it is simply a statement that such graphite is currently not produced in the quantity required and that the expansion of the electric car may be limited by this shortage. This can be alleviated to some extent by the production of ball graphite from larger flakes of graphite. However, the supply still isn’t there. This leaves artificial (pyrolytic) graphite meet this market; at an obvious cost.
The conclusion is that graphite at a reasonable cost is already in short supply and will become critical to the development of the automotive industry in the next few years.
Dr. Flint has been active in the graphite/graphene industry for over 25 years with experience ranging from engineering review, test work, pilot plants, process design, ... <Read more about Dr. Ian Flint>