A California start-up believes it has the key to unlocking the potential of a battery invented by Thomas Edison more than a century ago and using it to unleash a “sleeping giant” of global energy storage capacity.

Renowned American inventor Edison, who helped usher in the modern age of electricity, patented the first nickel-zinc battery at the turn of the 20th century. But its use as a rechargeable battery was limited as it would short-out after just a few cycles.

“Unfortunately for Mr Edison, he did not have access in 1901 to a scanning electron microscope,” said Michael Burz, the founder of battery developer Enzinc, which is seeking to revive Edison’s invention 120 years later.

What Edison would have seen with such a microscope are stalactite-like formations called dendrites, which grow rapidly in zinc batteries and eventually penetrate the layer separating its anode and cathode, causing it to lose power.

All batteries have this issue, but zinc-based ones get it particularly fast, lasting only 15 to 30 cycles. Lead acid batteries, which were also in use at that time, could get 300 cycles, said Burz. “Zinc was an also-ran.”

Naval call-up

Fast forward into the 21st century and the US navy has a problem. Their submarines are using an increasing array of sophisticated electrical equipment that demands increasingly powerful batteries to power it.

By this time, another kind of far more powerful battery has taken the world by storm. Lithium-ion batteries were first commercialised by Sony in 1991 to power Walkmans and laptops and were later put to an array of other uses, including by Elon Musk’s Tesla in a new generation of electric cars.

Lithium has issues. China has cornered the market.

“But lithium has issues,” said Burz. One is that China has “cornered the market” for the metal, often referred to as “white oil.” Lithium-ion batteries also have a tendency to overheat and, occasionally, explode, a problem affecting everything from phones to large-scale battery facilities.

The US navy had had just such a "bad experience" with lithium-ion, said Burz, with a mini-prototype sub powered by those batteries burning up in a dry dock.

Submarines to this day still largely use lead acid batteries, which are much safer. The issue is that – as well as being less powerful than their lithium-ion counterparts – lead acid batteries are far bulkier. And this is an issue for submarines, said Burz. “You can’t build an annex... you’re kinda fixed.”

In 2017, the US Naval Research Laboratory signed a licensing agreement with Enzinc – whose founder Burz had previously worked on the design of the Tomahawk cruise missile and built racing cars for Nissan – to look into reviving Edison’s nickel-zinc battery.

The key innovation cooked up in the naval research lab was a new sponge-like electrode, which it is claimed does not just slow down the formation of dendrites in zinc-based batteries, but stops them from appearing entirely.

Unleash the 'sleeping giant'

Enzinc has been working since then on commercialising this new electrode. Rather than manufacturing batteries itself, the start-up wants to sell these electrodes to the owners of lead acid battery factories, which Burz says could retrofit their facilities to produce zinc-based batteries that are as powerful as lithium and as safe as lead.

“One thing that people don’t know is that lead acid battery factories are worldwide,” said Burz, with 400GWh of capacity globally. “People built lead acid batteries where they needed them because who’s going to be shipping lead, it’s too heavy.”

If he could “wave a wand,” Burz imagines transforming these factories with his magical sponge-like electrode, which he says would triple their output to 1.2TWh.

Enzinc describes this on its website as “unleashing the sleeping giant” of lead acid battery factories.

Here, Burz said that the landmark Inflation Reduction Act passed in the US last year becomes significant, as companies can use its subsidies to upgrade their existing facilities to make high-performance rechargeable batteries.

Enzinc says batteries using its tech could be used for grid-based storage along with data centres, hospitals and factories. It would also work for electric cars and delivery trucks.

The start-up has formed an advisory group of 14 companies – both battery manufacturers and end-users – to help them guide and ultimately commercialise the electrodes. Burz says Enzinc is in the process of signing deals with two of those companies so they can build prototypes and test the technology before later moving into full production.

Battling the 'solution for everything'

The toughest challenge Enzinc is facing according to Burz is that “lithium has done such a good job” of marketing itself as the “solution for everything.”

“Overcoming people’s perception that the answer is just another version of lithium is difficult,” he said.

The other challenge is winning over the lead acid battery manufacturers he wants to sell to. “We’re trying to say, ‘look we’re helping you’” by allowing them to upgrade their existing facilities, said Burz. “But they want to see proof.”

“They should by rights be very sceptical,” he adds. “It’s their brand name that’s going to be on that battery.”

Battery makers including Enzinc face broader global pressures too. Russia is a major producer of battery-grade nickel, which Enzinc also uses in its technology. The price of nickel skyrocketed to $100,000 per metric ton after Russia invaded Ukraine, before settling back down to around $22,000. This is still double its pre-war price, however.

Breakthrough and revolutionary technologies in the battery and energy storage space more generally are announced with almost breathtaking frequency and the sector is gaining increasing prominence in the discussion around the green transition.

Burz said that he does not feel pressure from his myriad competitors, however. “One has to realise” that it takes around a decade to take a battery “out of the hands of scientists and into the hands of engineers,” he said.

“So when you see those announcements” about new breakthrough technologies, “wonderful,” said Burz. But he adds that, with all the manufacturing, quality, cost and regulatory issues, many of those technologies will “fall out along the way as they face the real-world challenges of making a commercial battery.”

Once he recalls being asked: “‘What’s a battery but an anode, a cathode and some engineering’. This was from a science person. That little phrase, ‘some engineering,’ is hundreds of people and millions of dollars.”

Energy storage tech is getting increased attention in the renewables discussion now and Burz said that, having worked in the industry for over a decade, he has for the first time noticed “people that I would call ‘battery groupies.’”

“Before you’d go to a party and people would say ‘what are you doing’ and I’d say ‘I’m working on a new battery’. They’d say, ‘oh what is that like a little AA battery or AAA?’”

Now if he goes to a party and says the same thing people understand and say, “‘oh, how exciting!’”