Why did anyone actually decide to work on lithium-containing batteries? This is because lithium is the lightest of metals, and in addition has the largest electrochemical potential among them – it can provide the most energy in relation to weight. However, there were some problems with its use in batteries. When lithium was the anode, cyclical battery charging caused it to expand and, as a result, to create short circuits. Short circuits led to a rapid increase in temperature, even to the melting point of lithium.
The first important step towards creating safer batteries lithium-ion has been made by M. Stanley Whittingham. While working on energy sources other than fossil fuels, Whittingham discovered an energy-rich material that the researcher decided to use to create the cathode (negative electrode) of his battery. This cathode was made of titanium disulfide and together with the anode (positive electrode) in the form of lithium metal formed a battery with a capacity of 2 volts. This battery was too unstable due to metallic lithium to be able to use it every day, but it had a very important feature. Now, Whittingham noticed that the cathode made of titanium disulfide had molecular spaces in which lithium ions could hide.
John B. Goodenough, working at the University of Texas at Austin, created a similar battery using cobalt oxide as a cathode (which also had the molecular spaces with lithium ions mentioned). His battery produced 4 volts of power and was a major breakthrough that would lead to even better batteries, which also happened.
Based on Goodenough cathode, Akira Yoshino developed in 1985 the first real lithium-ion battery that was suitable for commercial applications. Yoshino replaced the metallic lithium anode with a carbon material called petroleum coke, which was only saturated with lithium ions. This made the battery much safer.
Akira Yoshino lithium-ion battery. | Source: Johan Jarnestad / Royal Swedish Academy of Sciences
To date, many improved versions of lithium-ion batteries have been created, but who knows, if not for the three people mentioned, we would be dealing with such technology today. Meanwhile, it cannot be denied that this revolutionized our lives, pushing nickel-cadmium batteries out of the market offering much less possibilities.