Enzinc: ‘Zinc batteries go where lithium-ion cannot’

BY ROBERT MALTHOUSE

• Enzinc is offering a rechargeable zinc battery using sponge-type anode technology
  
• CEO Michael Burz says, unlike lithium-ion, zinc batteries can be safely used for storage in buildings
  
• Enzinc batteries have ‘no fire risk’, but convincing the market to use them could be tricky, admits Burz

Could zinc batteries usurp lithium-ion’s strong market position and become the storage technology of choice?

The potential certainly exists and Enzinc CEO Michael Burz is on a mission to make it happen.

Headquartered at the University of California in Berkeley’s Richmond Field Station in the San Francisco Bay area, Enzinc’s engineering team has developed a sponge-type anode technology made from zinc, and says it will be the first company offering a rechargeable zinc-based battery that can compete with lithium-ion.

Who’s backing Enzinc?

Enzinc created the anode using technology developed by the US Naval Research Laboratory. So far, Enzinc has raised north of $1.3m, mainly in the form of grants from the US Department of Energy and the California Energy Commission, as well as investments made by founders, senior advisors and angel investors.

The company recently completed 1,000 cycles of its test anode and is beginning to scale the technology into a small battery for commercial testing, which is scheduled to take place in the second quarter of next year.

Zinc batteries: Pros and cons

Non-rechargeable zinc batteries have been on the market for decades, being widely used in devices like children’s toys and TV remote controls. Over time, zinc has been increasingly used for a wide variety of energy storage facilities, though it has always relied on complex systems involving pumps, valves and tanks to operate effectively.

Zinc is an attractive material for energy storage purposes given it has a high specific energy (that is energy per unit mass) and high energy density (that is energy per unit volume). It is also plentiful, cheap and recyclable.

But the metal faces one major problem. And that is a short active life due to the build-up of dendrites – a needle-like formation that can cause short-circuit, failure, or even fires.

What gives Enzinc the edge?

While efforts to combat dendrites in recent years have been somewhat successful in reducing them, Enzinc claims its sponge technology can completely remove them, thus enhancing the qualities of zinc and making it an even more valuable component of energy storage systems.

“The advantages [provided by the sponge technology] are three-fold,” says Burz. “Firstly, it creates a more active surface area, meaning we get to use more of the zinc. Secondly, because of the structure, it eliminates dendrite growth – it doesn’t just slow it down, it eliminates it. And finally, because of its high-performance and rechargeability, it can be used in a family of batteries as it can be coupled with different cathodes for different applications.”

Zinc versus lead-acid batteries

Enzinc sees huge potential in the lead-acid batteries market not just in the developed world but in developing countries too. The market is currently valued at $50 billion and is expected to reach $77 billion in value by 2026.

Here’s the plan – in order to ensure zinc batteries start replacing lead-acid batteries, Enzinc wants to use its technology to partner with lead-acid battery manufacturers first.

“We’re going to help those companies design zinc batteries and then we’ll supply them the zinc anodes,” says Burz. Such a strategy would allow zinc batteries using Enzinc’s technology to utilise the existing equipment, expertise, sales and distribution chains to achieve a quick route to market, but also shift lead-acid battery companies’ focus to greener batteries.

‘Gorillas in the room’

While the lead-acid battery market is the company’s primary focus, the lithium-ion battery sector is also in Enzinc’s sights.

“Lithium-ion is like the 800lbs gorilla in the room, but lead acid is like the 700lbs gorilla,” says Burz. Currently, at the cell level, Enzinc claims its zinc-based battery is comparable – from an energy and costs perspective – to lithium iron phosphate technology.

But, ultimately, due to its advantages from a safety perspective, Enzinc believes the zinc sponge technology could outperform its competitor in the stationary energy storage market, both in relation to residential and commercial applications.

“For example, in the city of New York, lithium-ion batteries are not allowed to be used for energy storage within buildings”, says Burz, who adds that this presents a huge financial opportunity. “With approval from the New York fire department, our battery can go places where lithium-ion cannot as there is no risk of fire, given there is no thermal runaway.”

The challenge: Convincing the market

Despite Enzinc’s strides in developing its zinc-sponge technology, Burz notes that it hasn’t always been plain sailing.

“We have to go through a tremendous amount of testing, because batteries are critical to the green technology revolution… not just in their performance, but how they perform in the real world exposed to heat, cold, dust and so on,” he said.

But testing isn’t the only barrier to entering the market.

“We have to do a lot of education to convince people that it is worth their time and money to replace what they’ve known for the last 50 years with something new”, he added.

Biden’s backing

However, Burz is confident that this won’t be a lasting issue due to the massive increase in interest in batteries: “Even President Biden mentioned ‘advanced batteries’ in his address to congress, earlier this year.”

Burz says the fact that Enzinc’s zinc-sponge battery technology, as well as other energy storage systems can be put to so many different uses “from electric vehicles to energy arbitrage to data centres to even military applications” means it will play a vital role in the green transition.

And Enzinc is confident it has made a technological breakthrough, with a scalable strategy, that will enable it to make a big impression on the energy storage scene.