Zinc-Air Battery Technology

Why in News?

Indian researchers have developed new Zinc-Air Battery technologies that could provide a safer and potentially cost-effective alternative to conventional lithium-ion batteries. Recent innovations include low-cost electrolytes, improved catalysts, mechanically rechargeable batteries and electrically rechargeable prototypes. These technologies are being explored for electric vehicles (EVs) and long-duration energy storage.

What is a Zinc-Air Battery?

A Zinc-Air Battery is a type of metal-air battery that generates electricity through a chemical reaction between zinc and oxygen from the surrounding air. Its three major components are:

• Zinc anode: Zinc undergoes oxidation and releases electrons.
• Air cathode: Uses oxygen drawn from the atmosphere.
• Electrolyte: Enables movement of ions between electrodes.

Since oxygen is obtained directly from air rather than stored entirely inside the battery, zinc-air technology can offer a high theoretical energy density. Zinc is also relatively abundant and widely available compared with several critical minerals used in advanced lithium-ion batteries.

Major Zinc-Air Battery Innovations in India

A team led by Dr. S. Devaraj at SASTRA Deemed University, with support from the Department of Science and Technology (DST), developed a nanofluid electrolyte using silica and zinc oxide nanoparticles. The researchers also developed a copper-doped manganese dioxide catalyst and explored waste-derived carbon materials from discarded water filters and surgical masks. Researchers at IIT Madras are working on mechanically rechargeable zinc-air batteries, particularly for electric mobility. Hindustan Zinc and IIT Madras also partnered in 2024 to develop a 1 kWh electrically rechargeable zinc-air battery prototype using a water-based electrolyte.

Zinc-Air vs Lithium-Ion Batteries

Zinc-air technology offers several potential advantages:

• Zinc is relatively abundant and accessible.
• Aqueous electrolytes can reduce flammability risks.
• High theoretical energy density offers potential for energy-storage applications.
• It could reduce dependence on some critical battery minerals.

However, rechargeable zinc-air batteries still face challenges related to cycle life, charging efficiency, air-electrode durability and zinc degradation. Research is therefore focused on improving catalysts, electrolytes and rechargeability.

Important Facts for Exams

• Zinc-air batteries are a type of metal-air battery.
• Anode: Zinc.
• Cathode reactant: Oxygen from atmospheric air.
• Electricity is generated through zinc oxidation and oxygen reduction reactions.
• Potential applications include EVs and long-duration stationary energy storage.
• IIT Madras is developing mechanically and electrically rechargeable zinc-air systems.
• Hindustan Zinc and IIT Madras partnered to develop a 1 kWh prototype.
• DST: Department of Science and Technology.
• CeNS: Centre for Nano and Soft Matter Sciences, Bengaluru.
• Aqueous electrolytes are generally less flammable than the organic electrolytes commonly used in lithium-ion batteries.
• Major challenges include rechargeability, cycle life and electrode stability.