On a frigid day in early January, as she worked in her office in the Boston suburb of Billerica, Mass., Siyu Huang received a two-word text message.

“Spinning wheels,” it said. Attached was a short video clip showing a car on rollers in an indoor testing center.

To the untrained eye there was nothing remarkable in the video. The car could have been getting its emissions tested at a Connecticut auto repair shop (except it had no tailpipe). But to Ms. Huang, the chief executive of Factorial Energy, the video was a milestone in a quest that had already occupied a decade of her life.

Ms. Huang, her husband, Alex Yu, and their employees at Factorial had been working on a new kind of electric vehicle battery, known as solid state, that could turn the auto industry on its head in a few years — if a daunting number of technical challenges could be overcome.

For Ms. Huang and her company, the battery had the potential to change the way consumers think about electric vehicles, give the United States and Europe a leg up on China, and help save the planet.

Factorial is one of dozens of companies trying to invent batteries that can charge faster, go farther, and make electric cars cheaper and more convenient than gasoline vehicles. Transportation is the biggest source of man-made greenhouse gases, and electric vehicles could be a potent weapon against climate change and urban air pollution.