Roger Hanson: How lithium batteries could enrich Bolivia
Bolivia is one of the poorest countries in South America, however, that may not be for much longer because Bolivia has between 50-70 per cent of the world's known lithium reserves, up to 9 million tonnes, in a 10,500 square kilometre salt flat called the Salar de Uyuni.
There are deposits of lithium in Chile, Argentina, China and Australia.
Lithium has many uses but the ever increasing use of lithium in batteries has made it a valuable commodity.
Lithium is used in batteries because it develops a high voltage when used as a battery electrode.
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This property is called the electrode potential. Lithium is the third element in the periodic table, it has three protons in its nucleus – hydrogen is the first element, with one proton and helium is the second with two protons.
A proton has a positive charge and with three protons in its nucleus, lithium has a particularly high electrical charge for its small mass.
High electric charge and small mass are sought after properties for battery manufacturers.
Lithium is the least dense solid element which means that lithium batteries are light – unlike say lead-acid batteries.
Hydrogen, helium and lithium have another distinction, they are the only chemical elements that were synthesized by the energy and forces present very early in the history of the Universe - between 10 seconds and 20 minutes after the Big Bang.
For this reason they are sometimes referred to as the primordial elements.
The temperature immediately after the Big Bang was billions of degrees but had cooled sufficiently for the very simple atomic nuclei of hydrogen, helium and lithium to form without being ripped apart.
About 75 per cent of this primordial matter was hydrogen with one proton, 25 per cent was helium and 0.01 per cent deuterium. Deuterium is hydrogen with one proton and a neutron in its nucleus.
Lithium was present at this time but only in trace amounts.
Millions of years after the Big Bang the first stars began to form and the powerful gravitational crush of these big early stars enabled protons and neutrons to be forced close enough to form chemical elements which had many more protons and neutrons in their nuclei – stars are the factories for making the cocktail of 92 naturally occurring chemical elements present today.
The supernova explosions of these dying stars distributed these elements across the Universe, eventually to be swept up by gravitational forces to end up in planets like ours.
Lithium is chemically reactive, it combines readily with other elements such as oxygen and chlorine.
For this reason it is not found on the Earth in its pure metallic state but as lithium oxide or lithium chloride. It is reactive because of the way its electrons are arranged in their orbits around the nucleus.
Three electrons orbit its nucleus, two in its inner orbital shell and one electron in its outer orbital shell.
The negative charge of that electron in the outer orbit bonds extremely readily with oxygen and chlorine atoms which grab this lone electron to form a stable chemical bond with lithium.
The lithium in the salt flats of Salar de Uyuni is lithium chloride and sits under a hard salt crust.
Its concentration in the brine beneath the crust is about 0.3 per cent. The liquid brine is pumped to the surface and into large settling ponds where it is left to dry under the Bolivian desert sun.
The result is a slush containing lithium chloride and manganese chloride which after chemical processing delivers lithium metal.
This has to be vacuum packed to prevent it reacting with oxygen in the air.
With the rise of the electric car, the market for lithium batteries is set to increase dramatically, potentially making Bolivia wealthy, but Bolivia is a country with a terrible history of exploitation by foreign companies and given this background, the government wants to take full control of every aspect of its lithium business.
To date they have installed a pilot plant at Salar de Uyuni, this will be followed by a more substantial extraction facility and then it is hoped, as the demand from the electric car market moves into top gear, the money will start flowing.