TaiSan’s £4.65M Seed Backs Sodium-Ion Bet on Micromobility

TaiSan, the Cambridge-based UK startup developing quasi-solid-state sodium-ion batteries, raised a £4.65 million seed round to scale cells for electric bikes, scooters and power tools. The deal was co-led by Eos Advisory and the Midlands Engine Investment Fund II, managed by Mercia Ventures. Innovate UK added £700,000 in grant funding through its Investor Partnerships Programme. Investors returning from TaiSan’s pre-seed round include InnoEnergy, TSP Ventures, Exergon and Heartfelt. The funding announcement made no mention of the automotive manufacturers that anchored the company’s earlier message.

The capital is being deployed against a target list of e-bikes, e-scooters and power tools, with TaiSan citing letters of intent from manufacturers the release does not name. Sodium-ion chemistry has a lower energy density than lithium-ion, a smaller obstacle inside a scooter frame than inside a car. The shift matches what sodium-ion cells can already do at small scale. The shift also matches the funding environment for sodium-ion at large scale.

A Quiet Retreat From Electric Cars

TaiSan launched in 2022 with a battery-electric-vehicle pitch. Its 2024 pre-seed round was sold on a 20% projected cost saving over automotive lithium-ion, with the company claiming memorandums of understanding with automakers across seven countries. By July 2026, every one of those references has been dropped from TaiSan’s public materials.

Today, the company name-checks e-bikes, e-scooters and power tools as its target markets. TaiSan’s energy-density disadvantage versus lithium-ion is a smaller obstacle in a scooter frame than in a car. The fit between chemistry and product explains part of the pivot. The collapse of multiple sodium-ion competitors explains the rest.

TaiSan has not commented publicly on what changed. Pre-seed announcements referenced a “BEV industry” target, and a profile from the University of Cambridge’s impulse programme as recently as February 2025 still described TaiSan’s work as serving both the automotive and micro-mobility industries. The current website and announcement carry only the micromobility language. The letters of intent with micromobility manufacturers are not named, leaving open whether the BEV-era memorandums lapsed, converted, or were always lighter commitments than the language suggested.

Where the £4.65M Is Coming From

Eos Advisory and the Midlands Engine Investment Fund II, managed by Mercia Ventures, co-led the £4.65 million round. Innovate UK added £700,000 in grant funding through its Investor Partnerships Programme. The full list of 10 equity backers plus the grant is below.

The round added five fresh backers and kept all four pre-seed investors in place. New entrants include angel François Badelon alongside venture firms AFI Ventures, EverQuest Capital Partners, Adeline Arts & Science and Techmind. Returning investors InnoEnergy, TSP Ventures, Exergon and Heartfelt doubled down after backing the 2024 pre-seed. A round of this size split across 10 equity cheques plus a grant is the standard UK deep-tech seed construction, designed to spread the early-stage risk across many books.

TaiSan will use the funding to advance its technology and begin pilot tests with manufacturers. The company plans to open a new site in Coventry alongside its existing Cambridge battery lab.

The chemistry behind the round is a proprietary gel polymer electrolyte paired with a sodium-metal anode, designed to drop the heavy liquid electrolyte and bulky separators used in conventional sodium-ion cells. FinSMEs reports the configuration “allows them to pack more energy into a smaller volume.” That volume advantage maps onto micromobility frames, where a smaller, lighter cell is easier to fit into an e-bike down tube. The 2024 pre-seed sodium battery round had framed the technology around automotive lithium-ion equivalents. The new capital is, in effect, paying for the comparison to be reset at micromobility scale.

Sodium-Ion’s Hard Year

Sodium-ion technology was pitched as a cheaper, safer alternative to lithium-ion, built on abundant raw materials and detached from the supply-chain politics of lithium, cobalt and nickel. The pitch has not yet translated into commercial dominance at automotive scale. The market remains small. The shakeout has begun.

Faradion, a Sheffield-based sodium-ion startup, sold to Reliance Industries in 2024 after more than a decade trying to reach automotive scale. Natron Energy, a well-funded US rival backed by Chevron and United Airlines, shut down in September 2025 and abandoned its planned gigafactory in North Carolina. Mercia Ventures, one of TaiSan’s co-leads this round, had been an early Faradion backer, watching Faradion’s decade-long, incomplete drive to scale before Reliance bought it.

CATL still leads the sodium-ion market by volume, according to TechFundingNews coverage of the round. The total sodium-ion market is forecast to grow near 17% annually through 2031, off a base small enough that a single competitor’s collapse can move investor sentiment. Investors in TaiSan are buying into a chemistry whose commercial track record was reset by a series of high-profile failures. TaiSan’s total funding across pre-seed, seed and grants now stands at about £6 million.

• $546 million, estimated 2026 size of the global sodium-ion battery market (Mordor Intelligence, via TechFundingNews)
• $1.19 billion, projected 2031 market size, near 17% annual growth (Mordor Intelligence, via TechFundingNews)
• £1.3 million, TaiSan’s 2024 pre-seed round, led by EIT InnoEnergy and TSP Ventures
• About £100 million, Reliance Industries’ 2024 acquisition of Faradion
• $1.4 billion, value of Natron Energy’s cancelled North Carolina gigafactory

What the Investors and the Founder Are Saying

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” in the company’s seed announcement. He described TaiSan as “the kind of deep technology innovation… that we at Eos are dedicated to support.” At Mercia Ventures, investment manager Shubham Jaipuria said manufacturers are “seeking alternative technologies with a more reliable supply chain,” adding that TaiSan is “well placed to capitalise on this.” Both investors framed their checks as answers to a chemistry that needs cost, supply-chain and safety edges over lithium-ion. Neither investor addressed the missing automotive language in the announcement.

TaiSan’s founder and CEO Sanzhar Taizhan is a Kazakhstan-born former battery electrochemist who spent time at Jaguar Land Rover and The Faraday Institution. His work on quasi-solid-state sodium-ion chemistry was first covered in the Cambridge impulse battery innovation feature, where the company came to wider attention. Taizhan has not publicly addressed why the company deprioritised electric-vehicle cells.

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.

Sanzhar Taizhan, founder and CEO of TaiSan, said this in the seed announcement on 6 July 2026. The quote is the only on-the-record founder statement linked to the round.

The phrase “most exciting breakthroughs in stealth” is the closest thing to a public answer about why TaiSan moved away from electric cars. The company has, separately, told investors and partners that its pilot-test results will be published in stages. Until the first pilot data is public, the only visible explanation of the strategy reset is the market shift the new funding targets.

The Pilot Tests That Decide Everything

TaiSan says it will use the new funding to advance its technology and begin pilot tests with manufacturers. The startup is opening a new site in Coventry alongside its existing Cambridge battery lab. Pilot results will be the first public sign of whether the company’s pivot from electric-vehicle cells to micromobility is a retreat or a recalibration. The “stealth” breakthroughs Taizhan referenced will need to land in those tests.

The new funding announcement names no automaker partnership, no micromobility customer by name, and no third-party verification of the cost and energy-density claims from TaiSan’s pre-seed materials. Those claims, a 20% projected cost saving over automotive lithium-ion and energy density comparable to an automotive lithium-ion cell, were made when the company was still pitching to car-makers. The same InnoEnergy- and TSP-led consortium that backed that pitch has now committed again, this time through the existing-investor list of this round. Salt-chemistry advances at other labs are also drawing fresh attention, where a Tokyo University of Science sodium-ion charging study points to faster-charging cells. Until pilot data arrives, no outside reviewer has confirmed whether TaiSan’s cost and energy-density claims hold up in micromobility formats.

Mercia had backed Faradion before Reliance Industries acquired the Sheffield startup. InnoEnergy, with ties to European battery gigafactories, has committed again after backing the pre-seed. Both are now waiting on micromobility pilot results to decide whether to back further scale. The investment has spread across 10 equity cheques alongside the £700,000 Innovate UK grant.

Disclaimer: This article is for informational purposes only and does not constitute investment advice. Figures cited are accurate as of publication, 6 July 2026. Past performance is not indicative of future results. Readers should consult a qualified financial professional before making any investment decisions.