Offgrid Energy Labs Raises $15M to Develop Cost-Effective Zinc-Bromine Batteries for Renewable Energy Storage, Challenging China’s Lithium Dominance
Lithium batteries have long been the preferred choice for power systems due to their energy efficiency, but their limitations, particularly volatile supply chains and short lifespans, are becoming increasingly problematic. Offgrid Energy Labs, a deep-tech startup based in India, aims to reduce lithium’s dominance, especially in battery storage applications.
Founded at IIT Kanpur’s Startup Incubation and Innovation Center in 2018 by Tejas Kusurkar, Brindan Tulachan, Rishi Srivastava, and Ankur Agarwal, the startup has developed a proprietary zinc-bromine-based battery system as an alternative to lithium-ion technology. Dubbed ZincGel, it delivers 80–90% of the energy efficiency of conventional lithium batteries, but at a significantly lower levelized cost of storage, according to the startup.
As worldwide power demand grows and countries ramp up efforts to expand renewable energy storage, India, with its ambitious goal to increase non-fossil energy capacity tenfold by 2030, is no exception. New Delhi also aims to achieve 236 gigawatt-hours of battery energy storage capacity by 2031–32 and has announced a $612 million funding plan to develop 30 gigawatt-hour battery storage systems in the country. However, like many global markets, India faces a key challenge: China’s dominance over the lithium supply chain.
Offgrid Energy Labs believes its ZincGel battery technology can ease supply constraints by using widely available materials and offering a more cost-effective alternative to lithium-based systems. The startup has recently secured $15 million in Series A funding to scale up its operations, with plans to build a 10-megawatt-hour demonstration facility in the UK, expected to be ready by the first quarter of 2026, and begin commercializing ZincGel in the quarters that follow. A gigafactory in India is planned as the next phase.
“We aim to fill a gap in the market both from an application standpoint and a financial one,” said Kusurkar. “There have been technologies and batteries in the past globally, which have the solution, but they’re so expensive that they’re not widely adopted.”
The startup spent its first six years developing battery technology and has secured over 25 IP families and more than 50 IP assets across markets, including the U.S., U.K., India, China, Australia, and Japan. The battery is based on zinc-bromide chemistry with a proprietary water-based electrolyte, resulting in a low risk of fire.
ZincGel can handle longer discharges (6–12 hours) multiple times throughout its lifetime and can last twice as long as a typical lithium-ion battery, according to Kusurkar. Furthermore, the battery utilizes a carbon-based cathode for fast charging and discharging.
Zinc in batteries is not a new concept, and some companies have already offered zinc-bromide-based batteries, including Nasdaq-listed EOS Energy Enterprises. However, Offgrid Energy Labs uses its patented assets that help bring down the cost, and the ZincGel batteries can also reduce the need for using graphite, further reducing production costs.
“Customers care about the same performance or better price,” Srivastava said. “With ZincGel, we offer both.”
Offgrid Energy Labs’ technology is designed to allow for tweaking or sub-optimizing the battery based on the application. This means that these zinc batteries can operate independently of environmental conditions and provide energy storage even at temperatures as low as minus 10 degrees Celsius, Srivastava said.
The startup is targeting industries with net-zero goals that want to maximize renewable energy use by integrating battery storage. Its batteries are also being explored for applications such as peak shifting and decentralized, off-grid energy solutions. Shell and Tata Power are among the early testers, with talks ongoing with global players, including Europe’s Enel Group, to develop batteries tailored to their specific use cases.
So far, Offgrid Energy Labs has built its battery tech manually at a tinkering lab in Uttar Pradesh’s Noida. However, the startup plans to leverage its facility in the UK to demonstrate its technology to early customers next year. The UK facility will have a carbon footprint 50% lower than that of a typical lithium battery gigafactory, Srivastava said, adding that the startup has opted for simpler manufacturing processes to reduce both capital and operational expenses.
The Series A round was led by Archean Chemicals, a Chennai-based specialty chemicals manufacturer, which now holds a 21% stake in the startup, along with participation from Ankur Capital. Archean’s participation is strategic, as the publicly listed company has considerable expertise in bromine manufacturing and supply chain management. The startup is valued at around $58 million post-money.
