Why in the News?

Scientists at Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Bengaluru have developed a super-fast charging Sodium-ion battery.

About Sodium-Ion Battery and Its Working:

What it is: Sodium-ion batteries are rechargeable batteries that use sodium (Na⁺) ions to carry electric charge, instead of lithium.
How it works: During charging and discharging, sodium ions move between the anode (negative) and cathode (positive) — similar to how lithium-ion batteries function.
Innovation: A sodium-ion battery developed by JNCASR uses NASICON-type chemistry, a special material structure that ensures fast ion movement and stability.
Performance Boost: The team used nano-particles, added a carbon coating, and used aluminium doping to improve charging speed and battery life.
Fast Charging & Long Life: The battery can charge up to 80% in 6 minutes and last over 3,000 charge-discharge cycles.
Tested for Safety: The battery passed tests using electrochemical cycling and quantum simulations, proving it is safe and durable.

Sodium is abundant and cheaper than lithium, and it can be extracted from seawater.
Sodium-ion batteries are safer, as they can be transported at zero voltage and used in high temperatures without risk of fire.
They are more eco-friendly, with less environmental damage during extraction compared to lithium.
Material costs are lower because they use aluminium instead of copper.
India can reduce its dependence on China, which controls much of the lithium battery supply chain.
These batteries are ideal for renewable energy applications, such as solar grids, electric vehicles, drones, and rural electrification in extreme climates.

[UPSC 2025] In the context of electric vehicles, consider the following elements:

I. Cobalt II. Graphite III. Lithium IV. Nickel

How many of the above usually make up battery cathodes?

(a) Only one (b) Only two (c) Only three * (d) All the four