OElectricity would be pretty dark around us humans. No reasonably civilized life, no culture, no technical and scientific progress would be conceivable without it. We've gotten used to having access to this coveted form of energy at all times and places, even when there is no outlet within reach. This is mainly thanks to the performance of modern batteries, which can be recharged almost as often as desired and are now available in all sizes. They already supply all smartphones, laptops and many household appliances as well as more and more e-bikes, e-scooters and electric cars with electrical energy.
Batteries could one day also save the electricity generated from wind power and photovoltaics and thus help to compensate for fluctuations in the power grid. All this would not be possible without the groundbreaking research of Stanley Wittingham, John B. Goodenough, and Akira Yoshino. The three chemists will receive this year's Nobel Prize in Chemistry for the development of the lithium-ion battery.
The central components of a lithium-ion battery are – as in any battery – the two electrodes, the electrolyte and the separator. The latter separates the two electrodes from each other. The positive electrode (cathode) releases lithium ions, which migrate through the electrolyte to the negative electrode (anode) and are stored there. This generates an electrical current in the external circuit. Applying an external voltage reverses the process and recharges the battery.
Unruly Taming of Lithium
The alkali metal lithium has hitherto been the favorite in battery development. Because it is like no other element suitable for the construction of a powerful battery. On the one hand, lithium is the lightest metal, on the other hand, its electron is comparatively easy to remove. With lithium ions, therefore, can reach the highest electrical voltages. No other battery system has a higher capacity and energy density and brings more electrical power. For a long time the chemists knew about the impressive advantages of lithium for the construction of rechargeable batteries. However, the alkali metal has a great disadvantage. It is extremely reactive, especially when in contact with water. In addition, despite great efforts, it has not been stored in the electrodes for a long time.
The Briton Stanley Whittingham Finally, in the early 1970s, it was the first to find a workable solution. After completing his PhD thesis in 1968 at the University of Oxford, he spent four years at Standford University researching porous materials that could be used to incorporate charged foreign atoms. With this knowledge, he moved in 1972 to Exxon. There he examined how the electrical behavior of superconducting materials, such as tantalum disulfide, changed after introducing different ions. Whittingham discovered that the conductivity and energy density of the material increased when he experimented with potassium ions. When he measured the voltage, to his surprise, he measured a few volts with his meter. That was more than the then common batteries achieved. Wittingham immediately recognized the potential of his discovery and dedicated himself to the development of new batteries. He focused on car batteries.
. (tagsToTranslate) John Goodenough (t) Akira Yoshino (t) Briton Stanley Whittingham (t) John B (t) Exxon Mobile (t) ISIN_US30231G1022 (t) Electricity