Solid State Batteries

Subject: Science & Tech

Context- The move away from liquid electrolytes, which are highly flammable organic solvents.

Concept-

The government of India recently announced a major push towards solid-state battery research.
A consortium of 15 institutions, including the IITs of Bombay, Roorkee, Kanpur, Kharagpur, has been set up, with IISER as the lead centre.
This initiative of the Department of Science and Technology is one of three that constitute the ‘Integrated Clean Energy Material Acceleration Platform’.
The consortium “aims to accelerate the development of solid-state battery technology using AI [artificial intelligence] and ML [machine learning], through automated processes.

What are Solid-state batteries?

A solid-state battery is a battery technology that uses solid electrodes and a solid electrolyte, instead of the liquid or polymer gel electrolytes found in lithium-ion or lithium polymer batteries.
Such batteries can provide potential solutions for many problems of liquid Li-ion battery, such as flammability, limited voltage, unstable solid-electrolyte interphase formation, poor cycling performance and strength.
Solid state battery claims to prevent dendrites formation.
- It uses a solid-state separator technology that eliminates the side reaction between the liquid electrolyte and the carbon/graphite in the anode of conventional lithium-ion cells.
The replacement of the separator enables the use of a lithium-metal anode which is more energy-dense than conventional anodes, allows the battery to store more energy in the same volume.

Advantages of Solid State Battery:

The advantages of the solid-state battery technology include higher cell energy density (by eliminating the carbon anode), lower charge time (by eliminating the need to have lithium diffuse into the carbon particles in conventional lithium-ion cells).
It has the ability to undertake more charging cycles and thereby a longer life, and improved safety.
Lower cost could be a game-changer, given that at 30 per cent of the total cost, battery expenses are a key driver of the vehicle costs.
solid-state electrolytes are typically less reactive than today’s liquid or gel-type electrolytes.

What are Li-ion Batteries?

Lithium-ion batteries use aqueous electrolyte solutions, where ions transfer to and fro between the anode (negative electrode generally made of graphite) and cathode (positive electrode made of lithium), triggering the recharge and discharge of electrons.
The energy density of lithium-ion cells used in today’s mobile phones and electric vehicles is nearly four times higher than that of older-generation nickel-cadmium batteries.

Its limitations

Low energy density: Despite improvements in technology over the last decade, issues such as long charging times and weak energy density persist.
Small appliances: While lithium-ion batteries are seen as sufficiently efficient for phones and laptops, they still lack the range that would make EVs a viable alternative.
Extreme reactivity: One major problem is that lithium metal is extremely reactive.
Corrosion of cells: The main form of lithium corrosion is dendrites (branched lithium structures) that grow out from the electrode and can potentially pierce the separator short-circuiting the cell.
Fire hazard: In current lithium-ion batteries, in which the electrolyte is a flammable liquid, dendrite formation can trigger a fire.