Daimler has acquired a minority stake in US battery material specialist Sila Nanotechnologies for R&D purposes.

Founded in 2011, Sila Nano is a developer of new battery materials, said to outperform existing lithium-ion technology.

The company uses silicon for high-energy density batteries and new shareholder Daimler will get a seat on its board.

"Lithium-ion technology is currently the most efficient battery technology available, and still shows plenty of potential for the future. The advancements Sila Nano have made in battery performance are very promising. We are looking forward to a fruitful cooperation, pooling our know-how on further development and fast commercialisation," said Daimler's Sajjad Khan. 

Daimler said the acquisition expands its technological evaluation of materials and cells as well as research and development.

More work will be done on the current generation of li-ion battery systems, and on bought-in cells. 

Improvements to traditional li-ion battery chemistry have reached their limits. 

Sila Nano, based in Alameda, California, replaces conventional graphite electrodes with proprietary silicon-dominant composite materials that enable high energy density and high cycle life.

"These materials easily drop into existing li-ion factories, making it possible to deploy efficiently and at scale," the company said.