The forerunner in batteries for transportation is the lithium LiNiCoAlO2 cell. These are an “NCA” type lithium-ion battery. This battery is predicted to hit an energy density of 300 Wh/kg or 3.3 kg/kWh. With a lifetime of 500 cycles, they can last 10 years if charged every week.
Can we use this battery to power world transportation?
The first question is economics. Can the battery be produced at a low enough cost to make it financially viable. With more than half a million cars on the road to date, a major electric car manufacturer in the US has already answered that question for us.
The second question is do we have enough material? This can be answered using the USGS 2020 Mineral Commodity Summaries.
| Metal | Metric Tonnes | Location |
|---|---|---|
| Lithium | 80 million | Bolivia, Argentina, Chile, Australia |
| Nickel | 89 million | Indonesia, Australia, Brazil |
| Cobalt | 7 million | Congo, Australia, Cuba |
| Alumimum | 55 billion | everywhere |
| Graphite | 300 million | Turkey, China, Brazil |
Using the chemical formula for the battery and plugging in atomic weights, a percent by weight calculation can be performed.
| Element | Atomic Weight x atoms | % weight |
|---|---|---|
| Li | 6.94 x 1 | 3.8 |
| Ni | 58.69 x 1 | 32.0 |
| Co | 58.93 x 1 | 32.1 |
| Al | 26.98 x 1 | 14.7 |
| O | 16 x 2 | 17.4 |
| Total | 183.54 | 100 |
Cobalt is the largest battery component by weight. Taking into account USGS data it is obvious cobalt will be the limiting factor in how many batteries we can produce.
Let’s make a few assumptions to figure out how much cobalt is in these batteries.
Assumptions:
- 1/3 of the weight is insulators between the cathode an anode
- 1/3 of the weight is container packaging and support materials
- 1/3 of the weight is the cathode-anode pair with half of that being relevant to cobalt
This means cobalt should be rougly 32% of 1/6th of the total battery weight. Let’s call it 5% by weight. For a 75kWh battery, we would need 75 kWh x 3.3 kg/kWh = 248 kg of battery per vehicle. 5% of this weight would be 12kg of cobalt using the assumptions above.
Fortunately, industry insiders have better information than the assumptions made above and the latest “stage 3” batteries actually contain 4.5kg of cobalt per vehicle.
With current cobalt reserves of 7 million tonnes and 4.5kg of cobalt in each vehicle, we could theoretically put 1.5 billion cars on the road.
Unfortunately, cobalt also has other uses. Projected use in batteries is only 62% of world reserves. That takes us down to 930 million vehicles.
From OICA 2015 statistics the number of vehicles in the world were distributed as follows:
| Vehicle Type | Number |
|---|---|
| Passenger | 947 million |
| Commercial | 335 million |
Passenger vehicles are used for transport of passengers and defined as no more than eight seats. Commercial vehicles include everything else with wheels - transport trucks and buses. Commercial vehicle energy usage is higher than passenger vehicle usage.
In theory, cobalt based batteries could power the entire world passenger vehicle fleet if the world cobalt supply is exhausted. It will not power our commercial vehicles, trains, ships or airplanes. Passenger vehicle transportation is only a third of the energy used in world transportation.
Half of the world cobalt reserve is in the Democratic Republic of Congo. Environmental pollution is severe with radioactive uranium from mining operations polluting rivers and drinking water.
Child labour is problematic. Top tech firms were sued in December 2019 by families whose children had died due to unsafe mining conditions. A pilot project undertaken by mining companies in 2018 may improve conditions for children if it is rolled out universally. To date, the lawsuit is still before the courts.
Furthermore, the batteries only last about 10 years. If the cobalt cannot be 100% recycled from depleted batteries, our ability to reuse it for replacement batteries will be severely compromised. Recycling materials from manufactured products is always difficult.
Are we really selling out children in the Congo for a 10 year lease on the vehicles we drive around town?
Perhaps battery electric vehicles, especially the ones with cobalt, are not the best long term strategy for the world.