This startup replaces batteries with papers

This article is a part of Startup Spotlight, a series that features young, up-and-coming startups.

Image credit: Timmy Loen

Carlo Charles saw a foundational problem in modern electronics. The world relies on batteries that come with hidden costs, from mining-heavy supply chains to safety risks and massive waste. He launched Flint, based in Singapore, to rethink battery manufacturing using one of the world’s most scalable materials: cellulose.

😟Problem

The battery lifecycle is built on a linear model of extraction, use, and disposal. In North America alone, over three billion batteries are thrown away each year.

Improperly discarded lithium batteries are also driving a rise in waste-facility fires, with the US Environmental Protection Agency documenting 245 such incidents between 2013 and 2020.

💡Solution

Flint is developing paper batteries designed for safety and a circular end-of-life. The technology uses a cellulose-based structure and a water-based electrolyte, making it intrinsically non-flammable. It is engineered for low-toxicity materials and water-based manufacturing.

• It serves as a drop-in replacement, allowing brands to switch without redesigning devices.
• The design uses a cellulose structure and a water-based electrolyte for safety.
• It is built for end-of-life recovery and potential compostability pathways.

Photo credit: Flint

📊 Market size

The opportunity is driven by tightening regulations, such as the EU’s new Batteries Regulation, and increasing industry demand for sustainable alternatives. With the US discarding around 3 billion batteries annually, securing even a small share of this replacement market represents significant volume.

Flint targets high-volume brands where a single design win can lead to recurring annual demand for millions of units.

🤝 Team

Carlo Charles. Founder. Selected for Shell’s global innovation program. US State Department awardee representing Singapore. 

🚀 Traction

Flint has secured several early commercial and strategic partnerships.

• Selected into the Amazon Devices Climate Tech Accelerator to collaborate on decarbonizing battery supply chains.
• Selected as a 2025 winner of Logitech’s Future Positive Technology Challenge, and is piloting cells in select Logitech devices.
• Partnered with Nimble, sustainable electronics, to integrate its paper batteries into trackable travel accessories.
• Joined the Dassault Systèmes 3DEXPERIENCE Lab portfolio to support productization and scaling.

🏆 Competition

💰 Financials