Japan-Luxembourg startup bets on AC battery breakthrough for EVs — and beyond

JStories ー AC Biode has set its sights on revamping the future of electric vehicles (EVs). The Japan-Luxembourg startup has developed the world’s first standalone AC battery, a technology the company says is 15% more efficient than existing DC batteries and can last twice as long.

That innovation could change the future of electric vehicles, although it will be some time before AC Biode’s batteries find their way into next-generation EVs. “We’re working with some of the leading EV companies,” said co-founder Robert Kunzmann in an interview with JStories. “But AC batteries are an ambitious technology. They will take at least five more years before they reach the market.”

AC Biode Co-founders Tadashi Kubo and Robert Kunzmann        Photo courtesy of AC Biode (Same below) — AC Biode Co-founders Tadashi Kubo and Robert Kunzmann Photo courtesy of AC Biode (Same below)

Unlike conventional EV batteries, which must store direct current (DC), AC Biode’s system can safely store alternating current (AC) — the form of electricity used for transmission across power grids.

Today, most EVs rely on lithium-ion batteries that average about 377 kilometers of range — far less than gasoline or diesel cars. They are also heavy, which makes EVs significantly weightier than combustion-engine vehicles. If batteries can be smaller, more efficient, and longer lasting, more customers could be persuaded to switch to EVs.

Expanding beyond batteries

Even as AC Biode refines its AC battery, the start-up is developing other green technologies aimed at waste reduction, recycling, and renewable energy. “Sustainability is not a single country's problem but a global problem,” said Kunzmann. “Creating a world where we live in harmony with the planet earth may be the most meaningful mission.”

At the International Solar Festival held at the Osaka World Expo in July 2025, CEO Tadashi Kubo presented a new process to recycle solar panels. “Our technology can mechanically recycle solar panels and contribute to increasing recycling rates of solar panels after their use,” said Kubo. The company has already demonstrated its ability to separate and break down plastics in panels made by a major manufacturer, a step toward tackling the mounting problem of solar panel waste.

AC Biode Co-founder Robert Kunzmann giving a presentation about their various technologies

Old panels, which can contain harmful chemicals, are becoming a global issue. In India, a leading solar power generator, some 600 kilotonnes of solar waste are expected by 2030. Recycling technologies will be essential to prevent this renewable energy source from creating harmful side effects.

Beyond solar, AC Biode is advancing projects that include capturing CO2 and turning it into glass, converting plastic waste into oil feedstock, and replacing PFAS with fluorine-free alternatives. One of the closest to commercial use is Plastalyst, a chemical recycling technology.

AC Biode’s lab team holding samples of mixed textile and shoe waste, which they are testing for chemical recycling

“We are completing our first demonstration plant in Indonesia with PLN and Temasek Foundation,” said Kunzmann. “This will be the first time in the world to produce hydrogen from palm oil waste.”

A global start-up with global ambitions

Founded in 2019, AC Biode is headquartered in Luxembourg with operations in Japan. The company was established by Kubo, Chief Technical Officer Atsushi Mizusawa—who met when they were students at Cambridge University in the UK--and Kunzmann.

Kubo previously spent 12 years at Sojitz Corp., focusing on business development and project finance in batteries, machinery, infrastructure, and renewable energy across Africa and Latin America. Mizusawa, who holds a Ph.D. in material science, conducted research at Kyoto University and worked with Daikin and US-based IM&T Research. Kunzmann, with an engineering background, was a researcher at the Centre for Sustainable Road Freight in Europe.

“From day one, AC Biode has been a global startup,” said Kunzmann. “Our sustainability mission perfectly matches the backgrounds of the three founders.” With Mizusawa running the research lab in Japan, Kunzmann in Europe, and Kubo representing the company at conferences such as Tokyo Innovation Base’s Pitch Global 2025, AC Biode is able to operate across markets.

“In Japan we are leveraging the access to talent,” said Kunzmann. “Whereas Luxembourg gives us access to the European market and European Union grants.”

AC Biode’s team at their Kyoto laboratory

The future will almost certainly be electric.

Industries worldwide increasingly agree that batteries will power transportation and heating, while alternative fuels like hydrogen and e-methane will be used mainly in heavy industry and steelmaking, where electrification is harder to achieve.

By focusing on innovations such as the standalone AC battery, solar panel recycling, Plastalyst, and sustainable hydrogen, AC Biode is pursuing a broad but consistent mission: to move the world closer to a sustainable, circular economy.