Cocoon Carbon, a London-based materials technology company focused on scaling alternative inputs for concrete production, announced it has raised $15 million in Series A funding. The round was co-led by 2150 and Brick & Mortar Ventures, with participation from The Venture Collective and continued backing from existing investors including Wireframe Ventures, Celsius Industries, Gigascale Capital, and SOSV.
The funding will support the development of Cocoon’s first U.S. commercial demonstration facility and accelerate hiring across the United States and United Kingdom. The company is targeting deployment across more than 50 steel plant sites by 2035 as it works to expand supply of supplementary cementitious materials, which are critical inputs used to reduce the amount of traditional cement in concrete.
Concrete remains the most widely used material globally after water, but the supply of key cement substitutes is tightening. Historically, these materials have been sourced from coal plants and blast furnaces, both of which are being phased out across major markets. At the same time, infrastructure demand is rising, driven in part by large scale construction projects including data centers, with global infrastructure expected to double over the next four decades. Demand for supplementary cementitious materials is growing at approximately 6 percent to 7 percent annually, and prices have already doubled in some regions since 2017.
Cocoon’s approach focuses on converting steel slag, a byproduct of electric arc furnace steelmaking, into a high performance cement replacement. Electric arc furnaces, which recycle scrap steel using electricity rather than coal, produce tens of millions of tons of slag annually in the United States and Europe, with production expected to increase significantly through 2050. Cocoon’s process enables this material to be transformed into a usable input for concrete while reducing the embodied carbon of the final product by up to 40 percent.
The company has developed a rapid cooling technology that integrates directly into existing steel mill operations. By capturing molten slag and cooling it significantly faster than traditional methods, Cocoon is able to create a consistent and scalable supply of cement substitute materials. This approach avoids the need for new standalone production infrastructure, reducing capital requirements, energy usage, and operational disruption while also lowering transportation costs by colocating production at steel plants.
Cocoon has already piloted its technology at a major steel mill and completed third party validation of its material in concrete applications. Over the past year, the company has expanded its research and development capabilities, including a concrete testing lab in London.
The Series A funding will help validate the technology at commercial scale and establish the foundation for broader deployment across industrial sites in the United States and Europe. Cocoon is also expanding its workforce, hiring engineers, materials scientists, and commercial staff in the UK, along with plant operators and technical personnel in the United States.
KEY QUOTES
“The SCM market is facing a structural deficit at exactly the moment infrastructure demand is rising. We’re focused on delivering a plug-and-play solution that gives concrete producers access to affordable, local materials – while improving the economics of electric steelmaking. Expanding supply is the fastest way to stabilize costs and lower carbon in concrete.”
Eliot Brooks, CEO And Co-Founder Of Cocoon Carbon
“Concrete is one of the biggest value streams on the planet, providing the foundation of our civilization, from buildings to infrastructure to data centers. It consumes orders of magnitude more energy than AI and emits more CO2 than any other sector. Cocoon stands out in the innovation landscape with a product that is better and cheaper than cement and delivers a true drop-in replacement product for the industry.”
Jacob Bro, Partner And Co-Founder Of 2150
