This article originally appeared in the January/February 2025 issue of Startups Magazine. Click here to subscribe

The world is becoming ever more electrified and, ipso facto, the need for more powerful, compact, and sustainable energy storage solutions is also growing. However, the impact of traditional batteries, such as toxic manufacturing processes and finite recyclability, has long raised environmental concerns.

Time critical: more energy, more impact

Batteries are critical to the energy transition. They power everything from smartphones to EVs, but traditional lithium-ion batteries commonly use toxic solvents in their production, plus mining for materials like cobalt and lithium is resource-intensive, and recycling rates remain low. These are sizable drawbacks for the environment.

However, the global push for sustainability has spurred innovation in battery design and manufacturing, and companies are seeking ways to reduce their reliance on harmful substances, as well as tailoring batteries to meet specific industry needs and increasing recyclability. 

Thin-film technology allows batteries to be both lightweight and efficient, and it is positioning itself as a promising solution.

Rethinking thin-film batteries

BTRY is led by Futscher, a physicist whose journey through academia saw him studying everything from solar cells in Amsterdam to exploring battery technology in Zurich. Futscher has always had a passion for renewable energy and sustainability, and it is this passion that is the heart of BTRY’s mission.

Speaking on what spurred the idea for BTRY, Futscher said: “I saw in the lab how the [thin-film] technology was performing. At the same time, I talked extensively with industry and realised there was a strong interest in the technologies we were developing. That’s what inspired me to start the company.”

Although thin-film batteries are nothing new – having been around since the 1980s – BTRY has taken the concept a step further.

Futscher explains that traditional thin-film batteries have limited energy density due to their reliance on thick substrates, but by stacking the cells vertically it reduces the substrate's contribution, allowing it to achieve energy densities comparable to larger batteries all the while keeping the unique advantages of thin films, such as ultra-fast charging and long lifespans.

“We developed a proof of concept by stacking two cells directly on top of each other. By doing this, we halved the contribution of the substrate. T heoretically, stacking up to 10 cells could provide the same energy density as other batteries but with the fast-charging and long-life benefits of thin films.”

Customisable, sustainable, scalable

BTRY is initially focusing on Internet of Things (IoT) applications, particularly devices that require short, high-power bursts. Futscher explains that the company’s batteries replace the traditional pairing of a small battery with a capacitor, offering a single solution that meets both energy and power demands.

“The form factor is key. Our first battery is designed to be the thinnest on the market, making it ideal for applications like smart cards and labels, where ultra-thin design, reliability, and long life are essential."

Customisability is a big selling point for BTRY, and the company’s vacuum-based manufacturing process allows for batteries in any shape – from circular designs to more unconventional forms like a leaf, if that is ever what is needed, and more than that, the technology is scalable.

“We manufacture solvent-free using vacuum processes, which are widely adopted in various industries. These processes are proven and already used in mass production, for example, in the OLED and solar industries. T his makes them highly scalable. Our goal is to demonstrate that they can also be scaled effectively for battery manufacturing.”

BTRY’s commitment to sustainability is embedded in its processes, from sourcing materials to recycling, the company examines every aspect of the battery lifecycle to minimise environmental impact.

“Our vision is to extend electrification to applications previously limited by energy storage. We are committed to transforming industries through innovative, sustainable, and efficient battery solutions.”

Lessons learnt

Building a deeptech startup is no small feat, and transitioning from academia to entrepreneurship is a steep learning curve.

“In academia, you have the freedom to explore new ideas. In a startup, the focus shifts to delivering a product to customers. Managing finance, HR, and administration has been personally challenging, but it’s incredibly rewarding to see what a small, high-performing team can achieve.”

Despite the hurdles, however, BTRY has grown and fast. Founded in 2021, the company now boasts a team of nine and has partnerships that allow it to scale quickly without heavy capital investment. Collaborations with a multinational glass producer and research institutions like EMPA have been instrumental in accessing production facilities and refining processes.

Customer feedback has also been invaluable to the company. Initially, BTRY explored markets like aerospace and EVs, before zeroing in on IoT applications.

“In the beginning, we explored various markets, but it quickly became clear that IoT, especially smart cards and labels was the ideal entry point for our technology. Companies repeatedly told us that while the hardware is ready, batteries remain the bottleneck – the one thing preventing widespread adoption.”

Looking ahead

BTRY’s immediate goal is to scale production. It is currently limited by its research-focused equipment, so there are plans for a funding round in the coming year to expand operations. While the team is optimistic, Futscher recognises the challenges of operating in a market dominated by low-cost Chinese battery manufacturers and navigating the European funding landscape.

“There’s still work to be done in Europe to support deeptech startups. Many move to the US for capital. We’d like to stay in Europe but need to figure out how to make it feasible,” he said.

BTRY’s strategy of targeting niche markets, where existing solutions are limiting, positions it strongly in the competitive energy storage industry. By combining innovation with sustainability, the company is proving that batteries can be both high-performing and environmentally friendly, and as the demand for energy storage only continues to grow, BTRY’s approach could set a new benchmark for what’s possible in the field.