A former Kazakh chess champion has just made the right move in energy storage. Sanzhar Taizhan, founder and CEO of TaiSan, has closed a £4.65m seed round for the company, which operates out of the Cambridge battery lab. The funding will advance the startup’s proprietary sodium-ion battery technology and kick off pilot tests with manufacturers.

TaiSan focuses on a chemistry that is attracting growing interest as an alternative to lithium: sodium. The abundance of the raw material, potentially lower costs, and a less troubled supply chain than lithium’s make sodium batteries a credible candidate for electrifying bikes, scooters, light vehicles, and cordless power tools—segments where range is not the only critical parameter. The startup claims its technology offers higher efficiency than existing sodium-based solutions and even many lithium-ion counterparts.

The round was co-led by Eos Advisory and the Midlands Engine Investment Fund II, managed by Mercia Ventures. Also participating were AFI Ventures, EverQuest Capital Partners, Adeline Arts & Science, Techmind, and existing investors InnoEnergy, TSP Ventures, Exergon, and Heartfelt. Part of the capital—£700k—comes from a non-dilutive grant awarded by Innovate UK through its Investor Partnerships Programme. TaiSan had previously raised €1.7m in pre-seed funding.

“We are pushing the limits of electrochemistry in our mission to create more sustainable energy storage,” Taizhan said. “While we’ve kept our most exciting breakthroughs in stealth, this funding will help us enhance the performance of sodium-ion batteries and bring the benefits to a mainstream audience.”

For those tracking energy storage developments, sodium is an appealing alternative not only for light mobility but also for stationary applications where energy density is not the dominant factor. Compared to lithium iron phosphate (LFP) cells, sodium-based ones can offer a better thermal safety profile and tolerate extreme temperatures more easily, although they currently lag behind in cycle life and weight. TaiSan’s approach, still largely under development, promises to reduce precisely those trade-offs.

With the entry into the pilot phase, the company joins a handful of European and Asian players trying to industrialize sodium. The challenge is not just chemical: it requires scaling production, convincing large assemblers, and proving competitive costs in a market that has already made huge lithium investments. Having Cambridge and a deep-tech investor ecosystem behind it may help, but the road from lab to street is still entirely ahead.