- TaiSan has secured £4.65 million in seed funding, with Eos Advisory and Mercia Ventures leading the round through the Midlands Engine Investment Fund II. The company plans to use the money to develop lighter solid-state sodium-ion batteries for e-bikes, scooters, and power tools.
- Ten investors joined the round, along with a grant from Innovate UK. The founder said the company’s “most exciting breakthroughs” are still under wraps.
- This investment comes after the recent collapse of Natron Energy, a well-funded US sodium-ion competitor.
TaiSan, the Cambridge-based startup, has raised £4.65 million to develop solid-state sodium-ion batteries for e-bikes, scooters, vehicles, and power tools. Eos Advisory and the Midlands Engine Investment Fund II, managed by Mercia Ventures, led the round.
Innovate UK added £700,000 in grant funding through its Investor Partnerships Programme. In total, 10 investors took part.
The startup was founded in 2022 by Sanzhar Taizhan, a Kazakhstan-born former battery research electrochemist at Jaguar Land Rover and The Faraday Institution. The company first gained attention through a University of Warwick student team that made the finals of SpaceX and The Boring Company’s Hyperloop competition for three years in a row, the first England-based team to do so.
With this new funding, TaiSan’s total now stands at about £6 million, including the £1.3 million pre-seed round and nearly £500,000 in earlier grants. The money will go toward pilot tests with manufacturers and help TaiSan expand from its Cambridge lab to a new site in Coventry.
“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. Watch this space,” says Taizhan.
A revised strategy compared to 18 months ago
This confidence is different from what TaiSan shared with the market just last year.
In its previous £1.3 million pre-seed round, led by EIT InnoEnergy and TSP Ventures, the focus was on battery electric vehicles. TaiSan said it had signed memoranda of understanding with automakers in seven countries, and some reports mentioned as many as 19.
As recently as February 2025, a Cambridge University innovation programme profile still described TaiSan’s work as serving both the automotive and micro-mobility industries.
The £4.65 million announcement makes no mention of automotive manufacturers, earlier MoUs, or electric vehicles. Now, the focus is on e-bikes, scooters, and power tools, backed by unspecified letters of intent with prospective customers.
It is not clear if these are new or updated agreements. This shift makes sense because sodium-ion cells have lower energy density than lithium-ion, which is less of an issue for scooters than for cars. Still, this means investors are now backing a different direction than before, and TaiSan has not explained the change publicly.
A challenging sector
Sodium-ion batteries are seen as cheaper and safer than lithium-ion batteries because sodium is common and less affected by supply chain politics. However, this has not led to clear commercial success.
Faradion, a Sheffield-based startup, spent over a decade trying to reach automotive scale but was bought by Reliance Industries in 2024 for about £100 million after failing to do so on its own.
Mercia Ventures, which co-led TaiSan’s round, was an early backer of Faradion and has already seen one sodium-ion company’s long, incomplete journey. Even more notably, Natron Energy, a well-funded US rival backed by Chevron and United Airlines, shut down in September 2025 and cancelled a $1.4 billion gigafactory in North Carolina after failing to raise more capital. CATL, the Chinese battery giant, still leads the market by volume, leaving little space for smaller companies.
According to Mordor Intelligence, the sodium-ion battery market was valued at about $546 million in 2026 and could reach $1.19 billion by 2031, growing at nearly 17% annually. Even with this growth, the market is still small. Big events, like a company collapse or a major breakthrough, can strongly affect how investors feel.
10 backers in one seed round
The syndicate includes new investors such as AFI Ventures, EverQuest Capital Partners, Adeline Arts & Science, Techmind, and angel investor François Badelon, as well as existing backers InnoEnergy, TSP Ventures, Exergon, and Heartfelt.
In the UK, it is common to spread a £4.65 million round among 10 investors and a grant to share early-stage risk. But this also means no single investor takes full responsibility or has complete confidence in a technology that is still being tested.
Shubham Jaipuria, investment manager at Mercia Ventures, says manufacturers are “seeking alternative technologies with a more reliable supply chain,” and that TaiSan is “well placed to capitalise on this.”
Andrew Durkie, partner at Eos Advisory, called sodium battery technology “a credible and cost-effective alternative to lithium batteries, whilst addressing supply chain and safety concerns,” and described TaiSan as “the kind of deep technology innovation… that we at Eos are dedicated to support.”
TaiSan has raised significant capital and gained investor support. However, it has not explained why it changed its strategy or revealed the technology behind the shift. The results of current pilot tests should give a clearer picture of TaiSan’s future direction.
