LITHIUM – ION Batteries
- The 2019 Nobel Prize in Chemistry was jointly awarded to Stanley Whittingham, John Goodenough and Akira Yoshino for work that led to the development of lithium-ion batteries, which are used in most mobile phones, smartphones, tablets, laptops and power banks, among other devices.
- In the batteries, lithium ions move from the negative electrode through an electrolyte to the positive electrode during discharge, and back when charging. Li-ion batteries use an intercalated lithium compound as the material at the positive electrode and typically graphite at the negative electrode. The batteries have a high energy density, no memory effect (other than LFP cells) and low self-discharge.
- most Electrical Vehicles (EV) use Li-ion batteries as well, but are slowly reaching their theoretical limits of being able to provide roughly up to 300-watt hour per kilogram of energy. These batteries can also be used to store solar and wind power, which means that with their widespread use it may even be possible to live in a fuel free society.
- Researchers from IIT Guwahati have developed a technique which can precisely estimate one of the most important battery internal states known as SOC, short for state of charge. SOC reflects the remaining capacity of the battery, that is how much more charge can be withdrawn from the battery before it gets fully discharged. The knowledge of remaining capacity helps to optimize battery’s capacity utilization, prevent overcharging and undercharging of the battery, increases its lifespan, reduces cost, and ensures safety of the battery and its surroundings
- To improve a battery’s lifespan and optimize its capacity, it is important to predict its various states accurately. One of these states is the SOC, which has so far been difficult to estimate. Through their work, the researchers have proposed an approach that avoids overestimation and therefore helps in taking accurate measurements
Future of Batteries?
- Researchers from Australia claimed that they developed the world’s most efficient lithium-sulfur (Li-S) battery, capable of powering a smartphone for five continuous days — the equivalent of an electric car being able to drive a distance of over 1,000 km.
- Li-S batteries are generally considered the successors of Li-ion batteries because of their lower cost of production, energy efficiency and improved safety. Their cost of production is lower because sulfur is abundantly available.