Offgrid Energy Labs spent six years in R&D before moving toward commercialisation, and has secured over 25 IP families and 50+ IP assets.
Last week, Offgrid Energy Labs, a start-up incubated at IIT Kanpur, announced that it was setting up a 10 MWh demonstration facility in the UK. It said a giga factory in India would follow later.
Most energy storage today runs on lithium-ion. The problem: lithium is expensive, geopolitically concentrated, and poses fire risks at scale. Offgrid Energy Labs, which raised $15 million from the Chennai-based bromide manufacturer Archean Chemical Industries, is building an alternative.
Their proprietary technology – ZincGel – is a zinc-bromine-based battery system designed specifically for stationary energy storage — solar farms, industrial facilities, data centres and off-grid communities, rather than electric vehicles.
The core chemistry uses a water-based electrolyte, which eliminates fire risk and makes the battery significantly safer to deploy at scale. It delivers 80–90 per cent of the energy efficiency of a conventional lithium battery, at a lower levelised cost of storage, and lasts roughly twice as long — rated for 5,000+ cycles. It can also handle long-duration discharges of 6–12 hours and operate in temperatures as low as -10°C.
The company spent six years in R&D before moving toward commercialisation, and has secured over 25 IP families and 50+ IP assets.
businessline exchanged a series of emails with Dr Tejas Kursurkar, Co-founder, Offgrid Energy.
Excerpts:
Why did you choose to set up your first demo manufacturing facility in the UK instead of India?
The UK facility is a demonstration manufacturing plant designed to validate and optimise our production processes before we scale to commercial manufacturing. It is not a reflection of our long-term manufacturing strategy, but rather the fastest way to de-risk the technology in an ecosystem that offers strong R&D capabilities, supply chain readiness and early market adoption for clean energy technologies.
India remains central to our long-term vision. As one of the world’s fastest-growing energy storage markets, with ambitious renewable energy and storage targets, it represents a natural destination for future large-scale deployment and manufacturing. The knowledge, manufacturing processes and operational learnings from the UK demo facility will directly support our ability to scale efficiently and competitively for markets like India, where resilient, locally anchored battery supply chains will become increasingly important.
How far will ZincGel batteries help India wean itself away from China and support Atmanirbhar Bharat?
ZincGel represents an opportunity to diversify India’s battery ecosystem by reducing dependence on supply chains that are heavily concentrated around a handful of critical minerals and geographies. Today, while lithium-ion remains a good technology for certain uses, much of its value chain, from critical mineral processing technology to manufacturing, is concentrated in China, creating supply chain and geopolitical risks for not just India but the entire world.
ZincGel is built on zinc and bromine – materials that are far more abundant and geographically diversified. Zinc is mined at significantly larger volumes globally than lithium, and India is itself a major producer. On the bromine side, we are already working with Archean Chemical Industries, a Chennai-based company and one of our lead Series A investors, meaning part of the raw material supply chain is already anchored in India.
As India works towards its target of 500 GW of non-fossil power capacity and rapidly scales battery storage to support the grid, developing multiple battery chemistries will be critical for energy security. ZincGel is not intended to replace lithium-ion across every application. It is designed specifically for stationary energy storage, supporting renewable integration, grid balancing, industrial backup and microgrids, where long cycle life, safety, cost stability and supply chain resilience are often more important than energy density.
By enabling battery manufacturing around abundant, locally accessible materials, ZincGel can contribute to a more resilient and self-reliant energy storage ecosystem, complementing lithium-ion while advancing India’s Atmanirbhar Bharat ambitions.
What is the proprietary electrolyte, broadly?
Broadly, the proprietary electrolyte is a ZincGel proprietary mix. Chemically, it utilises a concentrated aqueous (water-based) Zinc Bromide foundation.
It incorporates a specific combination of two or more Zinc salts and also integrates specialised phase-stabilising additives to keep the chemical reactions controlled, stable, and non-flammable.
What are the cathode and anode materials?
Cathode: Coconut-shell activated carbon provides a massive, porous surface area to physically trap and stabilize oxidized bromine during charge. Conductive carbon blacks form the electrical network required for fast electron transport.
Anode (Anode-less): The cell is assembled without a zinc metal foil. On charge, zinc ions from the electrolyte plate directly onto a bare negative current collector. On discharge, this zinc layer strips completely back into the electrolyte.
How do you tackle dendrite formation?
Dendrite formation is tackled using proprietary additives to the electrolyte that act as leveling agents and grain refiners. They temporarily block microscopic high spots on the current collector, forcing incoming zinc ions to deposit evenly in the lower valleys. This lowers the nucleation overpotential, ensuring zinc plates as a dense, flat, and uniform layer rather than forming chaotic, needle-like dendrites.
Is there Hydrogen Evolution Reaction, and if so, how is it handled?
HER is tackled using a near-neutral electrolyte base and proprietary additives that suppress water reactivity. By tightly binding “free” water molecules within the electrolyte and anode surface energy, this combination expands the stable electrochemical voltage window of the system. This effectively prevents water from splitting, minimising hydrogen gas evolution and internal pressure buildup.
For how many hours has the battery been tested? A comment on the availability of Bromide?
The battery has undergone extensive long-duration testing protocol hours in-house using global standards and has been validated by leading third-party certification agencies like Intertek to ensure long-term cyclic stability and safety.
Bromine is highly abundant, cost-effective, and geographically secure. Crucially, it is heavily extracted from massive, highly concentrated domestic brine resources like the Rann of Kutch in India. This localised, abundant supply chain eliminates any reliance on scarce or politically volatile critical minerals like lithium, cobalt, or nickel.
Published on July 8, 2026
