By Anurag Sritharan
October 9th, 2019 the winners of the 2019 Nobel prize in Chemistry were announced by the Royal Swedish Academy of Science. Akira Yoshino (Japan), John B. Goodenough (US) and M. Stanley Whittingham (British American) were presented with the most coveted prize in science for the discovery of the lithium ion battery. Lithium ion batteries power the future of the human race. From quartz watches to Tesla cars lithium ion batteries play a crucial role in our daily lives. People under the age of 25 have not experienced life without the lithium battery. It is a necessity that is widely under-appreciated and most of us do not take time to understand how these batteries influence our lives.
To understand what are lithium batteries we have to define some key terms that will repeat throughout the article. All definitions are from the IUPAC (International Union for Pure and Applied Chemistry) website
1· Cathode: positive terminal of the lithium ion battery
2· Anode: negative terminal of the lithium ion battery
3· Electrolyte: s a substance that produces an electrically conducting solution when dissolved in a polar solvent, such as water. The dissolved electrolyte separates into cations and anions, which disperse uniformly through the solvent. (Polar solvent is not necessary to understand the article and therefore I will not define it but I will provide sources for further reading at the end of the article)
4· Cation: Positively charged ion
5· Anion: negatively charged ion
There are many types of lithium ion batteries using a variety of different compounds that have their own set of pros and cons. But, most of them have the same basic components: an anode, cathode and a separate. I will be talking about the most basic form the electrolyte version of the lithium ion battery.
From the picture above, it becomes clear what the roles of each component is and by connecting the terminals to a bulb or circuit you can power an electronic device. Usually the cathode is a compound that has a lot of lithium like lithium oxide (Li2O) and the anode is usually graphite as it can capture and store lithium ions from the cathode. Once the lithium is depleted from the cathode the remain charge in the electrolyte will cause a voltage drop and the battery dies. One notices this often in their phones. Once the phone battery drops to 20-10% there is a rapid depletion of the battery and the phone dies. The charging time for electrolyte batteries are longer and most everyday batteries such as the ones used in TV remotes do not recharge. Electrolyte type batteries are also affected by large temperature changes which can cause a variety of problems.
The above example is a simple set up used in tv remotes and 9V batteries a more complex one that is used in phones and cars such as the one below:
This is known as a solid-state lithium battery. They offer higher charge capacity or in general terms they last longer and give more charge before the voltage drop occurs. They are also resistant to changes in temperature since the electrolyte is protected in the core and there is a thermal insulator that is coated outside the battery. The downside being they are extremely expensive to make.
But why lithium? For people who want the quick answer it is because it charges faster and is more environmentally friendly. The longer answer takes into consideration the reactivity of lithium. Lithium is the 3rd element in the periodic table and is highly reactive. It produces ions even when a small charge is suppled. Also, being the 3rd element its radius is very small and thus we can have more atoms of lithium and create smaller batteries that will provide more energy. Lithium is also lightweight and highly conductive and very easy to carry around. Lithium is highly versatile allowing for a wide range of voltages and current to be produce from 3V to a couple kilovolts of power. This is why lithium was considered by the Nobel laureates.
The three winners did not work together as such but individually advanced the work of the predecessor. “The foundation of the lithium-ion battery was laid during the oil crisis of the 1970s. M Stanley Whittingham, 77, who was born in Nottingham, UK, worked to develop energy technologies that did not rely on fossil fuels.
He discovered an energy-rich material called titanium disulphide, which he used to make a cathode - the positive terminal - in a lithium battery.” (Rincon) John Goodenough suggested the use of a metal oxide rather than a sulphide and finally in 1985 Akira Yoshino developed the first commercially viable lithium battery and in 1991 Sony released the first commercial lithium battery.
Since 1991 lithium batteries have powered phones and recently cars have started using lithium batteries. Since 1991 Japan held a leading edge over the world in lithium ion battery manufacturing but more recently South Korea and China have seen a huge increase in lithium ion battery production due to the search for sustainable electric cars. The Tesla Roadster was the first commercial lithium ion battery powered car made in 2008. Since 2015 we have seen a rise in all electric cars such as Nissan, Toyota and Hyundai. Luxury car manufactures such as Jaguar and BMW have also invested heavily in lithium ion battery development and all electric cars. The rising market has caused tensions between the three Asiatic countries and a sort of “battery war” is taking place. South Korea however seems to have taken the lead as shown in the table below
CALT is Chinses while Panasonic is Japanese the last three are Korean.
The mobile phone market and general everyday lithium batteries still hold its roots in Japan since many companies still employ the same combination of chemicals as the first battery. But, can India rise up to the challenge, Mahindra and Tata have their own electric cars and lithium ion battery production. The mobile phone market has also shifted in the favor of India as Apple started to invest heavily in the country. The gadgets that lithium ion batteries power are from tv remotes to phones and iPads, laptops to cars. What is next for the mighty battery that powers the future of the human race.
Work cited
1. IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997). Online version (2019-) created by S. J. Chalk. ISBN 0-9678550-9-8. https://doi.org/10.1351/goldbook.
2. Writer, Staff. “Battery Wars: Japan and South Korea Battle China for Future of EVs.” Nikkei Asian Review, Nikkei Asian Review, 14 Nov. 2018, asia.nikkei.com/Spotlight/The-Big-Story/Battery-wars-Japan-and-South-Korea-battle-China-for-future-of-EVs.
3. Rincon, Paul. Nobel Chemistry Prize: Lithium-Ion Battery Scientists Honoured. 9 Oct. 2019, www.bbc.com/news/science-environment-49962133.
Photos
1. The Four Components of a Li-Ion Battery. www.samsungsdi.com/column/technology/detail/55272.html?pageIndex=1.
2. “Silicon Lightworks.” Battery Powered Trade Show Exhibit Lighting, siliconlightworks.com/li-ion-voltage.
3. Writer, Staff. “Battery Wars: Japan and South Korea Battle China for Future of EVs.” Nikkei Asian Review, Nikkei Asian Review, 14 Nov. 2018, asia.nikkei.com/Spotlight/The-Big-Story/Battery-wars-Japan-and-South-Korea-battle-China-for-future-of-EVs.
Comentários