M. Stanley Whittingham-one of Noble Prize Winner 2019
Time : 2019.11.04
Both electric vehicles and alternative energy sources require powerful batteries to store large amounts of energy.In fact,there were only two types of rechargeable batteries on the market at the time: lead-acid batteries invented in 1859 (still used as starting batteries for fuel vehicles) and nickel-cadmium batteries invented in the first half of the 20th century.
M. Stanley Whittingham was one of the scientists who joined Exxon in 1972. He is from Stanford University and works on certain solid materials.These materials have an atomic size space that allows charged ions to adhere to them. This phenomenon is called intercalation.When ions are trapped inside the material, the properties of the material change.At Exxon,Stanley Wettingham and colleagues began researching superconducting materials, including antimony disulfide that can intercalate ions. They added ions to the antimony disulfide and studied how their conductivity would be affected.
Whittingham discovered a substance with extremely high energy density
As is often the case in science,this experiment brings an unexpected discovery.It turns out that potassium ions affect the conductivity of bismuth disulfide.When Stanley Whittingham began to study this material in detail,he observed that it had a very high energy density.That is to say,the interaction between potassium ions and antimony disulfide has an amazing energy.When Wittingham measured the voltage of this material,it was found to be several volts, which is much better than the battery at the time.Stanley Whittingham quickly realized that it was time to change direction,and he turned to a new technology that can store energy for future electric vehicles.However,helium is a relatively heavy element, and there is no need to load heavier batteries on the market.Therefore,he replaced the bismuth with titanium, which is similar in nature to bismuth but much lighter.
Lithium as a negative electrode
In the story of lithium-ion batteries, lithium began to occupy the most important position. As the negative electrode of Stanley Whittingham's new battery, lithium is not a random choice. In the battery, electrons should flow from the negative electrode (anode) to the positive electrode (cathode). Therefore, the negative electrode should use a material that easily loses electrons, and among all the elements, lithium is the most desirable element for releasing electrons.
As a result of this, Stanley Whittingham has developed a rechargeable lithium battery that can operate at room temperature, which has a large potential and great potential. He went to Exxon's headquarters in New York to discuss the project. The meeting lasted about 15 minutes and the management team quickly made the decision: they would use Stanley Whittingham's discovery to develop a commercially viable battery.
Battery explosion and oil price drop
Unfortunately, the team that is preparing to start producing batteries has encountered some difficulties. As the new lithium battery is repeatedly charged, a thin layer of lithium species begins to appear on the lithium electrode. When they reach the other electrode, the battery will short-circuit and cause an explosion. The fire brigade had to fire a number of times to put out the fire, and they threatened to pay for the special chemicals used to extinguish these lithium battery fires. In order to make the battery more secure, aluminum was added to the metal lithium electrode, and the electrolyte between the two electrodes was also replaced.
Stanley Whittingham announced his discovery in 1976, after which the battery began small-scale production for a Swiss watchmaker and planned to use it in solar-powered watches. The next step is to expand the battery capacity so that it can charge the car. But in the early 1980s, oil prices suddenly dropped dramatically, and Exxon needed to cut costs. The related research work was stopped and the technology invented by Whittingham was granted to three different companies in three different regions of the world. But this does not mean the end of the research work. When Exxon gave up the work, John Goodenough took over.
Like almost all human production activities, the production of lithium-ion batteries also has an impact on the environment, but it also brings great benefits to the environment. With lithium-ion batteries, researchers were able to invent cleaner energy technologies and electric vehicles, effectively reducing greenhouse gas and particulate emissions.
Yoshino Akira developed the first commercially available lithium-ion battery. He used Gudinaf's lithium-cobalt oxide at the cathode and used a carbon-based material called petroleum coke at the anode, which also inserted lithium ions. When the battery is functioning, it does not destroy its own chemical reaction. In contrast, lithium ions can flow back and forth between the electrodes, greatly extending battery life.