AmpliSi Raises £2M Pre-Seed to Replace Graphite in Lithium-Ion Batteries With Its Scalable Silicon Anode

March 12, 2026

AmpliSi, the Sheffield-based battery materials company, raised £2 million in a pre-seed round in March 2026, led by Northern Gritstone and the Clean Growth Fund. The funding will support AmpliSi’s transition from laboratory development toward industrial scale-up and early engagement with battery manufacturers. AmpliSi is a spinout from the University of Sheffield, co-founded with company builder Cambridge Future Tech, and was part of Northern Gritstone’s NG Studios deeptech venture-building cohort in 2025. It is led by CEO Ruth Sayers, alongside co-founders Siddharth Patwardhan and Gwen Chimonides.

The lithium-ion battery is the dominant energy storage technology for electric vehicles and grid-scale applications, and its performance is central to the pace of the energy transition. But the anode — one of the two electrodes in a lithium-ion cell — is a binding constraint on how far that performance can improve. Conventional anodes are made from graphite, a carbon material with well-understood electrochemistry but a theoretical capacity ceiling: graphite can absorb roughly 372 milliamp-hours of charge per gram. Silicon, by contrast, has a theoretical capacity nearly ten times higher — around 3,579 mAh/g — and its use in anodes is one of the most actively pursued routes to batteries with greater energy density, longer range, and faster charging. The challenge is that silicon expands by up to 300% when it absorbs lithium ions during charging, causing it to crack, lose contact with the electrode structure, and degrade rapidly — making pure silicon anodes impractical in conventional manufacturing formats.

AmpliSi’s approach is to use porous silicon structures rather than solid silicon particles. The porosity provides internal space for the material to expand during lithiation without cracking or losing structural integrity, while also improving the surface area available for lithium-ion exchange. The company produces its porous silicon through a proprietary low-temperature conversion process that starts from abundant silica — essentially refined sand — rather than the energy-intensive, high-temperature chemical vapour deposition processes that characterise competing silicon anode production routes. This matters commercially as much as technically: lower process temperatures mean lower energy costs, lower capital requirements, and a manufacturing route compatible with existing supply chain infrastructure rather than requiring purpose-built facilities.

Northern Gritstone CEO Duncan Johnson described AmpliSi as embodying the kind of deep-tech innovation from the University of Sheffield that the fund was created to support — combining world-class science with a credible route to commercial impact through supply chain compatibility. Clean Growth Fund partner Beverley Gower-Jones noted that silicon anodes have long been recognised as offering dramatic performance advantages over graphite, and that AmpliSi’s technology addresses both the performance gap and the manufacturing emissions challenge that has held the technology back from wide adoption. Cambridge Future Tech’s Owen Thompson pointed to AmpliSi as an example of what is possible when novel research is matched with hands-on venture building and the right capital. The mobility sector’s demand for higher-density batteries — driven by consumer pressure for longer EV range and faster charge times — creates substantial commercial pull for a material that can be integrated into existing battery manufacturing lines without wholesale retooling.

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