AmpliSi

AmpliSi is a Sheffield-based battery materials company developing next-generation silicon anode technology for lithium-ion batteries. The company was spun out from the University of Sheffield, where the underlying research was conducted at the Green Nanomaterials Research Group led by Professor Siddharth Patwardhan. AmpliSi was co-founded with company builder Cambridge Future Tech and participated in Northern Gritstone's NG Studios deeptech venture-building cohort in 2025.

The lithium-ion battery is the dominant energy storage technology for electric vehicles and grid-scale applications, yet its performance is constrained by the graphite anode used in conventional cells. Graphite has a theoretical capacity ceiling of approximately 372 milliamp-hours per gram, which limits the energy density achievable in battery cells. Silicon offers nearly ten times higher theoretical capacity, but conventional silicon anodes crack and degrade rapidly during charging due to extreme volume expansion, making them impractical in standard manufacturing formats.

AmpliSi's approach uses porous silicon structures rather than solid silicon particles. The porosity provides internal space for material expansion during lithiation, preventing the cracking and structural degradation that has historically limited silicon anode performance. The company produces its porous silicon through a proprietary low-temperature process using silica — one of the most widely available materials on earth — which avoids many of the hazards, high costs, and scalability challenges of conventional silicon anode production methods. This process also carries a lower emissions intensity than competing approaches, supporting battery manufacturers seeking greener supply chains.

In March 2026, AmpliSi raised £2 million in a pre-seed round led by Northern Gritstone and the Clean Growth Fund. The funding will support the company's transition from laboratory development toward industrial scale-up and early engagement with battery manufacturers. AmpliSi is targeting the electric vehicle and grid storage markets, where demand for higher-performance, lower-cost anode materials is accelerating.