Electric Vehicles have gotten a lot of media attention over
the last few years. The United States, with the rest of the developed world,
have made a push to reduce emissions and improve air quality in our cities. We
use things like O2 sensors and Air Fuel Ratio sensors, along with catalytic
converters, in order to reduce the impact that gasoline engines have on the
environment. Recently, companies have been exploring ways to abandon gasoline
consumption all together and produce “zero emissions” vehicles in the form of
electric vehicles, like the Nissan Leaf. Although people have thoughtfully
explored the impact of producing the electricity needed to charge the battery,
all of the green-enthusiasts are conveniently looking away from the real issue:
the lithium ion battery itself.
Nissan Leaf |
Lithium is a soft, silver-white alkali metal with the symbol
Li on the periodic table. It does not occur freely in nature; it only appears
in compounds that are usually ionic. Lithium salts are extracted from the water
of mineral springs, brine pools, and brine deposits. The metal is then produced
via electrolysis from a mixture of fused lithium chloride and potassium
chloride.
The brine is usually pumped to large pools to let the sun
evaporate the salts to a high enough concentration. Then this potent solution
is pumped onto trucks and driven to processing facilities. Currently, 61% of
the world’s lithium production occurs in Chile. Worldwide reserves of lithium
are estimated at about 13 million tonnes. Using the battery efficiency figure
of 400 g of lithium per kWh, this gives a total maximum lithium battery
capacity of 52 billion kWh which, assuming it’s used exclusively for car
batteries, is enough for 2 billion cars with the same size battery as a Nissan
Leaf.
Lithium brine pools |
Problem is, only 25% of the world’s lithium goes into the
manufacture of batteries (and that includes batteries for laptops and cell
phones). Lithium is used for processing
silica to make glass, as a major component in high temperature grease, in air
purification systems, in nuclear weapons, and even in pharmaceutical drugs to
treat bi-polar disorder. The world’s supply of lithium would be exhausted
relatively quickly if we tried to run most of the world’s vehicles on
lithium-ion batteries.
In response to this claim, many bring up the fact that
Lithium batteries can be recycled, and thus diminishing the problem of
depleting this rare metal. The problem with this is that lithium is rather
volatile at room temperature, so the entire battery has to be cooled down to
-345°F
before it can be dismantled and recycled. Cooling batteries down to such
extreme temperatures uses a tremendous amount of energy, reducing the favorable
environmental impact lithium ion batteries are supposed to have.
In reality, with a rapidly expanding population and ballooning
consumption of energy worldwide, there is no magic solution to solve our
emissions problems and save the world. Continuing current habits of every
individual driving and using inefficient means of transportation, along with
the host of other issues with consumer culture, leaves little doubt that our
current style of living is unsustainable. Save for the unlikely invention of
cold fusion, we are going to have to re-evaluate the way in which we travel.
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