Thilo Braun: MBA ’23: An Electric Approach to Cleaner Skies

Stanford Impact Founder Fellow is developing aviation batteries that could keep the world flying — sustainably.

October 11, 2023

| by Sarah Murray
Portrait of Thilo Braun

Thilo Braun | Drew Kelly

As someone who is passionate about aviation but also has deep concerns about climate change, Thilo Braun wondered how to reconcile the two. Global aviation is responsible for around 5% of global warming effects and severe pollution around airports. Yet, “Aviation is beautiful,” Braun says. “It connects people and cultures.”

Braun grew up in China and relied on air travel to get home to see family and friends in his native Germany. In China, he also became acutely aware of the problems associated with air pollution. “There were days where I remember coming out of my dorm at the university, and I couldn’t see the emergency exit sign at the end of the corridor because there was so much smog in there,” he recalls.

The combination of a passion for transportation and a desire to help tackle climate change led Braun to London, where he studied engineering at Imperial College. He then spent three years working at Lilium, a startup that was developing electric flying cars, where he undertook everything from developing financial models to designing factories and recruiting employees.

This and other experiences, including an internship at an investment bank, gave him many of the tools he needed to embark on his mission to create a clean form of aviation. While studying for his MBA at Stanford GSB, he started his investigations in earnest.

At Stanford, he met his co-founders. Venkat Viswanathan, a Carnegie Mellon University professor, is a leading expert on batteries for aviation. “One of my professors in the Stanford Climate Ventures class introduced us,” he recalls. “I was evaluating a business idea around electrifying cargo aviation, and the professor said I had to talk to him.” Meanwhile, fellow student Shashank Sripad spearheaded work on electric aviation in his lab. Given their expertise and shared interests, the combination was a perfect fit.

After spending a year looking into the potential of hydrogen, including working part-time for a startup called Universal Hydrogen, the co-founders concluded that, as Braun puts it, “hydrogen is useful, but the transformative case for aviation is going to be electric.”

“I’d love to see new forms of aviation emerging that are only possible because of the work that we’ve done,” he says. “Flying cars and air taxis — these become a possibility when the batteries are there.”

The Problem

In developing batteries for aircraft, Braun and his co-founders are tackling problems on many fronts. The first and most obvious is the contribution aviation makes to global warming, not only by burning jet fuel, releasing large amounts of carbon dioxide into the atmosphere but also through other byproducts such as nitrogen oxide and the water vapor seen in a plane’s contrails.

In addition, people living near airports — often low-income, underserved communities — are disproportionately affected by aircraft exhaust fumes that contain lead and fine particle emissions.

People living near airports — often low-income, underserved communities — are disproportionately affected by aircraft exhaust fumes.

Meanwhile, Braun and his team’s solution faces a big challenge: batteries are heavy. “The big thing with aviation is that it’s more weight sensitive than almost any other application,” explains Braun. “So if you took the same batteries in an electric vehicle, they would be too heavy to have enough energy and power for an aircraft.” And the amount of power required for an aircraft take-off and landing is immense, he adds.

Moreover, battery technology has what is known in the industry as the “and” problem: batteries for transportation need to be light and durable and low-cost and safe. Improve performance for one or two of these characteristics, and it can lead to trade-offs in others (hence the name of Braun’s company, And Battery Aero, or ABA).

“The devil is in the details,” says Braun. “You increase the energy, and the power goes down, you increase the power, and the safety goes down, or the charging speed goes down.”

The Novel Idea

Braun and his co-founders are working on designing and producing battery systems for aircraft that will be up to 50% lighter than anything currently in development, and that will be safety-certified by both the European Union Aviation Safety Agency and the U.S.’s Federal Aviation Administration.

The team has funding from ARPA-E, the U.S. energy research agency, and has several technology partners for the battery cell and materials development.

ABA’s system will rely on three core elements: novel high-energy battery cells, an innovative battery pack that will contain the cells and a battery management system that will enable safety monitoring and control. “On the technical side, we have results from the tests that are incredibly promising for what we think we could achieve,” says Braun.

The second part of the puzzle is the work the team is doing with potential customers. “We’ve been able to bring on several big-name players in the electric aviation industry who’ve signed up as commercial partners,” Braun says.

These companies have been providing ABA with their requirements, including details of how they would use the batteries so the team can test its batteries in the context of real-world use cases. “That’s where we have confidence that we’re heading in the right direction,” says Braun.

The Innovator

As his parents like to remind him, the first word Braun uttered as a two-year-old child was “pilot.” And he is not the first family member with a passion for aviation. His great-granduncle helped build the first German aircraft and was a founding member of Lufthansa.

His family has inspired him in other ways, too. Soon after moving the family to China, Braun’s mother found herself without a job after the mobile phone company she had been working for declared bankruptcy. While she could have returned to Germany, where she would have easily found work, she decided the family would remain in Beijing so that Braun could complete his international education.

There, she launched and built her own management consulting and coaching company. Braun, who was then 11 years old, remembers the family dining table covered with papers and Post-it notes while her mother developed her business plan — something that left a deep impression on him.

“It demystified the whole process of starting a business,” he recalls. “Yes, it’s hard, and I saw her suffering through the process, but in the end, it’s not rocket science.”

His mother’s resilience in the face of a setback also taught him the value of persistence. “She’s a true inspiration,” he says. “She never takes no for an answer.”

Braun tries to apply the same approach as he and his team work to turn ABA into a successful business. Keeping the vision and mission in mind, he treats every setback as a learning opportunity. “I know we have a chance to make it,” he says. “So it’s knowing that if we keep going, we’ll get a step closer every time.”

Plenty of work lies ahead. The “and” problem will not be solved overnight. And while the team is increasing its use of data analytics and is applying models to predict what works and what doesn’t work, the process is arduous.

However, Braun feels confident that they have what it takes to find the right solution — Viswanathan with strong science and battery expertise, Sripad driving the engineering and technical work, and Braun with his aerospace and industry experience.

“Electric has a truly transformative nature,” Braun says. “It’s way cheaper to operate, it enables new aircraft designs, and it eliminates all the emissions we have from flying.”

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