Zinc makes in-roads in batteries market

While debate rages over whether lithium-ion and vanadium reflow energy storage systems will usher in the next wave of power generation, another technology, batteries that store energy using zinc, is moving into the market.

Zinc batteries, especially the technology being marketed by Vancouver, British Columbia-based Zinc8 Energy Solutions, has attracted considerable attention in recent weeks with a new type of viable, lower-cost energy storage option for many large customers such as utilities and others with large power needs.

Zinc empowers the lowest cost of storage in the market for long-duration applications, resolving the intermittent and unpredictable nature of other renewable energy sources, while completely decoupling the linkage between power and energy, according to Zinc8.

The availability of this long-duration, low-cost storage is opening up a new trillion-dollar energy storage market for utilities, behind-the-meter applications and micro-grid developers. More and more companies are looking to move toward zinc-powered long-duration technology that is more affordable and practical.

"We're opening up a market that currently doesn't exist," Zinc8 President, CEO and Director Ron MacDonald said in a recent interview. "And we're really in a good spot because we think we have a four- to seven-year advance on any competitor coming into this market."

Zinc-air technology breakthrough

Zinc-air battery technology had long been touted as a potentially cheap and powerful form of energy storage, but it always seemed to have a fundamental flaw - the formation of a bumpy coating of zinc on the electrode called a dendrite, which caused short circuits and other problems.

Zinc8's technical team overcame this hurdle by embracing the flaw and turning it to the company's advantage.

"Most of the zinc-air battery research was focused on an electrolyte that would eliminate or reduce the dendritic formation," Zinc8 chief technology officer Simon Fan told a reporter recently. "We took a totally different approach - we like dendrites."

Fan's team invented a process - which remains a trade secret - that easily removes the dendrite from the electrode to "give us beautiful dendritic particles that we can transfer to the storage tank".

In developing its zinc-air battery technology, the company has acquired 20 patents.

How the battery works

Zinc8 says its batteries are capable of storing multiple days' worth of energy, that doesn't degrade, can't possibly explode and is up to five times cheaper than lithium-ion batteries.

Moreover, the Zinc8 battery uses electricity from the grid to split the chemical zincate (ZnOH4) into zinc, water, and oxygen, resulting in charged zinc particles that can store electricity for weeks at a time and is regenerative. When electricity is required, the charged zinc is combined with oxygen from the air (and water), releasing the stored electricity and producing zincate, which is then cycled back to begin the process again.

The battery itself consists of three parts - the "zinc regenerator", which generates the charged zinc particles; the storage tank, which contains the potassium hydroxide electrolyte and holds the charged zinc; and the power stack, a kind of fuel cell that turns the zinc to zincate and delivers its charge back to the grid.

The zinc can be stored for months in the electrolyte - it literally accumulates at the bottom of the storage tank - although it loses about 1% of its stored charge per day. And these particles are then pumped to the power stack when required, via a proprietary pumping mechanism designed and built in-house, where the charge is extracted and delivered to the grid.

The electrolyte - in which the zinc is formed - does not degrade, being identical at the start and finish of each cycle, and there is no net consumption of zinc, oxygen or water. The only parts of the system that degrade are the electrodes and the power stack, which need to be replaced every few years, depending on usage.

The round-trip efficiency of the system – the percentage of inputted energy that is outputted at the end – is about 65%, a far cry from lithium-ion's 95%, but this is offset by the lower cost of the battery.

Marketing headway

Some observers say Zinc8's zinc-air battery has the potential to disrupt the entire energy-storage market - making wind and solar farms baseload and even replacing the need for transmission grid upgrades in many places.

Earlier this year, the company entered an agreement to build an energy storage system for New York Power Authority in western New York. The company won the New York Power Authority Innovation Challenge, a tender aiming to find innovative eight-hour-plus storage technologies. The company won the opportunity in competition with 60 other technologies.

Zinc8 is now collaborating with New York Power Authority, the largest state utility in the United States, on building a 100kilowatt/1 megawatt-hour (i.e. 10-hour) pilot project for a commercial NYPA customer in western New York state by 2022. This project will showcase the long-duration aspect (20-plus years) of the battery and validate the data so that Zinc8 can join NYPA on many of their future projects.

"This is the thing that's changed our company – going from having some interest, but nobody thinking that zinc-air was ready – to our phones ringing nonstop from big utilities and globally connected companies around the world," added MacDonald. "It gave us a level of credibility, of realness with the bigger, broader market that would have taken us a lot of time and a lot of banging on doors [to achieve].

Inquiries have been coming in from multinational utilities, transmission system operators, large and small wind and solar developers, EPC (engineering, procurement and construction) companies, technology developers wanting to collaborate on control systems and even lithium-ion battery companies, according to MacDonald.

He said NYPA has been very supportive, and is providing $2.55 million of funding towards the project to help accelerate the development of the technology

Since then, Zinc8 has agreed to build a 100kW/1.5MWh (15-hour) zinc-air system in Brooklyn for New York-based clean-energy developer Digital Energy, a project that is being financially supported by the New York State Energy Research and Development Authority.

In early June, the company also said it has created a wholly owned U. S. subsidiary in New York state, named "Zinc8 Energy Solutions (USA) Inc."

A third commercial pilot of about 40kW is due to be installed in Surrey, B. C., in the first quarter of 2021.

Because of their lower cost, MacDonald said he believes the zinc-air batteries could replace the need for expensive upgrades of transmission lines in grid-constrained areas like New York State.