What breakthrough innovation in renewable energy storage, which replaces liquid electrolyte with a solid one, was announced in 2025?

Correct option is A

The correct answer is (a) Solid-state sodium-ion battery

Explanation:

• In 2025, researchers announced a breakthrough in Solid-state sodium-ion batteries, which utilize a solid electrolyte instead of the traditional flammable liquid.
• These batteries are seen as a cheaper and more sustainable alternative to lithium-ion batteries because sodium is much more abundant than lithium.
• The use of a solid electrolyte significantly reduces the risk of fire and allows for faster charging and higher energy density.
• This innovation is particularly vital for large-scale renewable energy storage (solar and wind) and Electric Vehicles (EVs).
• The solid-state design prevents the formation of dendrites, which often cause short circuits in liquid-based batteries.

• A battery electrolyte is the medium that allows the flow of electrical charge between the cathode and anode.
• Sodium-ion technology is critical for India's National Mission on Transformative Mobility and Battery Storage to reduce import dependency.

• This technology focuses on high power density and rapid discharge but is usually not classified as a solid-state replacement for standard electrolytes.

• 'Fusion' refers to a nuclear process; while Hydrogen Fuel Cells exist, a 'fusion battery' remains a theoretical concept for the distant future.

• This focuses on wearable tech and high capacity using silicon anodes, but doesn't specifically define the 2025 solid-electrolyte breakthrough mentioned.