These paper batteries — yes, paper — are the best of the CES winners. They come for your technique

Sometimes it can feel a little depressing to wander the halls of the world’s biggest tech show and find so few things designed to tackle our planet’s biggest problems. Every time I attend CESI keep my eyes open for technology that has the potential to make its mark on society in a deeper way, and at this year’s show I discovered a humdinger. (Here are some more from the most impressive finds.)

Read more: The official best of CES 2025 winners awarded by CNET Group

Singaporean startup Flint makes rechargeable paper batteries, which CNET picked as the winner of the CES Best of Sustainability Award on Thursday. They are completely flexible and can be shrunk down to the size of a coin battery or built into a smartwatch strap.

Flint’s paper batteries share a structure with traditional lithium-ion batteries, but that’s where the similarities end. Their key component is cellulose, which acts as a natural medium for the transfer of ions between the anode and cathode, a critical chemical exchange required for battery operation.

The mining and manufacture of lithium-ion batteries is responsible for significant CO2 emissions, leakage of toxic chemicals and depletion of waterways, all of which contribute to the wider climate crisis. As our demands for batteries increase rather than decrease, solutions like Flint’s are key to reducing the environmental impact of our technological obsession.

“Our supply chain is very abundant and we don’t need rare earths or toxic materials and scarce materials,” said Flint co-founder Carlo Charles. Some of them, like zinc and manganese, can even be found in your food and body, he added.

Disposing of traditional batteries also puts a huge strain on the environment, but paper batteries can break down biodegradable within six weeks. Charles told me that the team’s office in Singapore composts their used batteries to feed the plants in the office.

The company is currently focused on making smaller batteries for smaller consumer electronics, but there’s no reason they can’t expand someday. “We want to go even further and see how we can build our products into your smartphones,” said Charles. “Foldable smartphones can have foldable batteries in them… there’s so much potential.”

Much further down the line, the paper battery could be scaled to fit inside the door of an electric door or the wing of an electric airplane. Because the batteries are so thin, they can be layered and also don’t pose the same fire hazard as their lithium-ion predecessors.

In the week leading up to CES, Flint secured $2 million in funding, which the company plans to use to build a pilot manufacturing facility in Singapore. Locating the pilot project in a country without cobalt, lithium or other minerals traditionally used to make batteries will help prove that the battery industry can be decentralized, Charles says.

The company already has plans to return to CES next year with an even bigger presence – although this year’s booth was an impressive feat of sustainable engineering in its own right. The whole thing was made of cardboard that could be packed into a single box.

It was with all of this that Flint planted a flag at CES 2025. We’re excited to see where the company’s paper batteries go next.