New 'Rechargeable Sun Battery' Outperforms Lithium-Ion

UC Santa Barbara scientists unveil a bio-inspired molecule that promises to revolutionize solar energy storage.

Published on Feb. 26, 2026

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Researchers at UC Santa Barbara have developed a groundbreaking new material called pyrimidone that can store solar energy as heat, outperforming traditional lithium-ion batteries in energy density. This 'rechargeable sun battery' is inspired by DNA and can be used for off-grid heating, residential water heating, and more.

Why it matters

This innovation represents a significant leap forward in Molecular Solar Thermal (MOST) energy storage, a field focused on using molecules to capture, store, and release solar energy as heat. By integrating storage directly into the material itself, this technology could streamline the solar energy process and reduce costs compared to traditional solar panel and battery systems.

The details

The pyrimidone molecule functions like a mechanical spring, twisting and straining to store energy when exposed to sunlight. This stored energy can then be released as heat on demand, with the addition of acid acting as a catalyst. The material boasts an energy density of over 1.6 megajoules per kilogram, surpassing the 0.9 MJ/kg of standard lithium-ion batteries.

  • The research was published in the journal Science in February 2026.

The players

Grace Han

Associate Professor at UC Santa Barbara and lead researcher on the project.

Han Nguyen

Doctoral student and lead author of the study published in Science.

Ken Houk

Professor at UCLA who collaborated with the UC Santa Barbara team on computational modeling to understand the molecule's stability and energy storage capabilities.

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What they’re saying

“The concept is reusable and recyclable.”

— Han Nguyen, Doctoral student and lead author

“With solar panels, you demand an additional battery system to store the energy. With molecular solar thermal energy storage, the material itself is able to store that energy from sunlight.”

— Benjamin Baker, Coauthor

What’s next

The research team is actively working towards commercializing the technology, but it is still in its early stages.

The takeaway

This 'rechargeable sun battery' represents a significant breakthrough in renewable energy storage, offering a more efficient and sustainable alternative to traditional lithium-ion batteries. The potential applications, from off-grid heating to residential water heating, could help drive wider adoption of solar power and reduce reliance on fossil fuels.