Geely's premium EV brand is already using such technology in its first model, the Zeekr 001.

Capital, the venture capital arm of Nio, and have invested in a Chinese developer of smart color-changing glass, a new technology that is expected to be introduced into future models.

Nio Capital and BYD recently completed a strategic investment in electrochromic technology developer Ambilight, for an undisclosed amount, according to Nio's venture capital arm.

The strategic investment was followed by Ambilight's completion of a multi-billion dollar Series C round led by Warburg Pincus with participation from Dinghe Gaoda and Cygnus Equity.

These new financing will be used for new electrochromic product research and development, capacity expansion, and global commercialization rollout.

Ambilight was founded in 2017 and has offices in Shenzhen, Silicon Valley, and Indiana, according to the company's website.

In March, the company closed a Series B financing round of tens of millions of dollars led by Matrix Partners and CPE.

Over the past four years, Ambilight has used its technology for mass-producible products including automotive roofs, anti-glare mirrors, architectural curtain walls, cell phone back cases, and AR glasses.

Geely's premium brand Zeekr is already offering the electrochromic roof option on its first model, the Zeekr 001.

At the launch of the brand update today, Xpeng Motors Chairman and CEO He Xiaopeng said the company had considered introducing the technology in its products several years ago, but gave up because it was too difficult.

With its adjustable light transmission, electrochromic material technology re-empowers traditional glass with the ability to control light and temperature, and has trillions of market applications in the automotive, architectural curtain wall and consumer electronics sectors, said Zhu Yan, managing partner of Nio Capital.

Ambilight's third-generation electrochromic flexible film has the world's leading process and cost advantages for mass production applications, according to Zhu.

Nio Capital looks forward to working with Ambilight to help innovative companies in the materials space move forward, added Zhu.

Electrochromic materials are typically a cross-disciplinary technology that has been active in academia for nearly half a century.

While it holds great commercial promise, it has been unable to be prepared on a large scale due to its technical difficulty and high barriers.

The third generation of flexible solid-state electrochromic materials developed by Ambilight's in-house has become a gas pedal for the widespread adoption of this technology.