By Jennifer Kho

Thin Battery Technologies has raised $6.2 million to expand production of its ultrathin carbon-zinc battery, a low-cost device the company claims is more environmentally friendly because it doesn’t contain heavy metals.

John Gannon, a general partner with investor SunBridge Partners, said Wednesday the batteries were well suited to companies that make disposable radio frequency identification (RFID) tags and companies producing medial patches that deliver drugs through the skin. Mr. Gannon estimated the potential battery market for each of those applications at more than $1 billion each.

“The battery has the potential to be cheaper, and it is also completely disposable, giving it a significant advantage over lithium-based products in the market,” he said.

SunBridge Partners led the Series-A round. Other investors include Early Stage Partners, Key Capital, Orix Capital, and individual investors. Thin Battery Technologies CEO Gary Johnson said the round brings Thin Battery Technologies’ total funding to nearly $8 million.

Thin Battery Technologies, which spun out of Eveready Battery in 2002, has developed a battery that can literally be printed onto the devices they power, using traditional printing equipment. Most thin-film batteries use a lithium-based chemistry, but Thin Battery uses a carbon-zinc compound, which is cheaper and more environmentally friendly.

More Surface = More Power

To battery buffs, the idea might sound strange at first. After all, carbon-zinc is the chemistry that alkaline batteries replaced, said Brian Barnett, a managing director at consultancy TIAX. But carbon-zincs become more powerful when they have more surface area; in other words, when they’re made into a flat shape, he said.

Still, even the thin-film carbon-zincs have less energy density than lithium-based batteries, meaning they don’t deliver as much power or last as long.

But Thin Battery Technologies is targeting low-power applications, Mr. Johnson noted. “The lithium cells certainly have their place,” he said.

Thin Battery Technologies already is providing batteries for Sealed Air’s TurboTag radio-frequency device that logs time and temperature data for the coal industry. The company says the batteries are being produced “in the low hundred thousands” through standard high-speed printing subcontractors.

One advantage is that the batteries perform better than lithium-based batteries in very cold conditions, Mr. Johnson said. They also are disposable, printable, potentially far cheaper than lithium-based batteries, and compliant with the European Union’s environmental laws, he added.

With its fabless approach, the company says it could easily increase production to millions of batteries in a few months, and tens of millions within the year, without significant capital investment. By the time it reaches the low millions, the batteries should be cheaper than lithium-based batteries, Mr. Johnson said.