The widespread adoption of electric vehicles (EVs) is a crucial step in combating climate change, but current battery limitations have deterred many potential consumers. EV batteries face challenges such as limited range, slow charging, short lifespans, and safety concerns. To address these issues, Adden Energy has developed an advanced lithium-metal solid-state battery technology. The company recently secured $15M in a Series A funding round, led by At One Ventures, to scale production and bring this solution to automakers.
“Current EVs are suitable for people like me—those with access to at-home charging and who typically take short commutes or the occasional road trip,” explained Adden Energy Co-Founder and CEO, Will Fitzhugh. “But that’s not enough. We need to provide batteries that put EVs on par with internal combustion engines in every consumer-facing aspect.”
A major barrier to EV adoption lies in charging limitations, especially for the over 120 million Americans who live in homes without dedicated parking, making at-home charging unfeasible. Additionally, commercial vehicles often exceed a million miles in their lifetimes—far beyond what conventional lithium-ion batteries can support. Safety concerns, particularly the high flammability of current battery systems, further inhibit EV adoption.
Adden Energy’s breakthrough solid-state batteries are poised to achieve EV parity with internal combustion engines by 2028. Based on research from Harvard, their technology combines two key innovations: lithium-metal batteries and fast-charging capabilities. Lithium-metal offers the highest energy density of any battery material, promising longer range and lower costs compared to current batteries. However, past efforts to utilize lithium metal have been hampered by dendrites—microscopic metal filaments that grow within the battery, leading to failure, especially under high charge rates.
In 2022, Adden Energy was spun out of Harvard to commercialize technology that prevents dendrite growth entirely. “Every battery has imperfections or defects that dendrites exploit,” said Harvard Professor and Adden Energy Co-Founder, Xin Li. “Instead of trying to create defect-free batteries—which is nearly impossible—we’ve developed components that self-heal during use, stopping dendrite formation. This innovation not only tackles manufacturing defects but also mitigates damage that may occur throughout the battery’s life.”
The self-healing solid-state separator, exclusively licensed to Adden Energy from Harvard, enables safe and efficient use of lithium metal, allowing the battery to exceed traditional limits. Adden Energy’s prototypes currently lead the industry, charging in under 10 minutes and offering nearly 10 times the lifespan of standard batteries.
The recent funding, with contributions from Primavera Capital Group, Rhapsody Venture Partners, and MassVentures, will enable Adden Energy to build a pilot production facility at its Waltham, MA headquarters. The company has already demonstrated the world’s fastest lithium-metal battery in EV-compatible pouch cell formats, and this funding will allow them to scale production by 100 times.
Laurie Menoud, Partner at At One Ventures and Adden Energy board member, noted, “We are in the midst of an exciting transition from a fossil fuel economy to a materials economy, and this battery technology maximizes material productivity. Lithium-metal anodes will reduce the cost per kilowatt-hour by 30%, driving significant EV adoption.”
Adden Energy’s growth aligns with federal and state efforts to boost U.S. battery manufacturing through initiatives like the Inflation Reduction Act and the Bipartisan Infrastructure Law. The company is positioned to lead the next generation of battery technology in this rapidly evolving sector, with support from both the federal government and the State of Massachusetts.
“Adden Energy exemplifies the cutting-edge climate tech innovation coming out of Massachusetts,” said Economic Development Secretary Yvonne Hao, Chair of the MassVentures Board. “A spinout from Harvard, MassVentures provided early support to help the idea evolve into commercialized technology with huge potential for clean energy. We’re thrilled to see Adden Energy grow and scale right here in Massachusetts.”
