UL is part of a science safety enterprise that organizes essential testing for products prior to commercialization.
Salient's zinc-ion cells were the first of their kind to be tested by UL. The results showed the batteries do not experience thermal runaway, nor do they produce toxic or explosive gasses even when subjected to extreme heat, puncture or overcharging.
As CEO Ryan Brown put it, "When you have a water-based battery, it's hard to make it catch fire."
The concept for Salient began in 2016 with a PhD research paper at the University of Waterloo. After about four years of research and development, the company moved to Dartmouth, N.S.
"We found that there was a different approach one could take to making rechargeable zinc batteries that would allow for compact, dense design, and a really long service life where you could recharge it thousands of times, which has never before been achieved in zinc batteries," said Brown.
The battery's chemistry consists of a zinc anode, a pH-neutral zinc sulphate electrolyte and a manganese oxide-based cathode.
The zinc-ion battery
One of the advantages behind developing a zinc-ion battery is the abundance of zinc compared to the looming strangulation of the lithium supply chain.
According to Salient's website, annual global production of zinc stands at 12.8 million tonnes, whereas lithium stands at 0.1 million tonnes.
BloombergNEF’s second annual Global Lithium-Ion Battery Supply Chain Ranking in October 2021 found Canada placed fifth in battery supply chain potential behind Sweden, Germany, the U.S. and China in that order.
According to the company, zinc emits one-third of the greenhouse gas emissions of lithium, on top of being 50 per cent cheaper.
With that in mind, Salient will source its zinc from Alaska — home to 3.5 per cent of the world's reserves, which when mined is worth over $1 billion each year.
It will also source manganese from Mexico. In 2021, Mexico's manganese mine production amounted to approximately 225.7 thousand metric tonnes.
"If you want to very quickly scale up a battery that will be able to deliver globally, you need to use a mature supply chain, which means not only a bunch of mines producing a bunch of the raw material, but a bunch of people processing them to the purity that batteries need," Brown explained.
"That's available for zinc, and it's available domestically. So the world's biggest zinc mine is in Alaska, and then they process it all in Quebec."
Brown emphasized the importance of a North American domestic supply chain given China's battery dominance and external events like the war in Ukraine causing disruption.
Future of the zinc-ion battery
In January 2021, Salient received a grant from the California Energy Commission totalling about $1.5 million to support battery development.
Currently, Salient has a pilot plant in Dartmouth which Brown says produces enough for UL testing and pilot products for customers. From there, the plan is to build a factory "to get out the first couple million bucks worth of sales."
That factory, with a location still to be determined, would likely begin operation in 2024 or 2025. In the immediate future, plans for pilot products continue.
"We're making products for the residential market, which means we got to make battery packs and then make a home battery," Brown said. "We need to get that UL certified, and then we need to ship that to our first customers, which we plan to do by the end of next year for (the) pilot project, showing this thing works in the real world."
Sustainable housing and battery recycling
In May this year, Salient announced a partnership with sustainable homebuilders Horton World Solutions (HWS) in Texas. HWS will host Salient’s zinc-ion storage system for installation in its planned construction of over 200,000 homes. HWS founder and CEO Terry Horton also sits on Salient's board of advisors.
Those first homes will naturally be in California and Texas. Brown highlighted California thanks to its status as the largest market in North America. Both states are ideal, though, because of the difficulties involved in allowing batteries to work in sub-zero temperatures.
He also envisions a future where Salient implements a battery recycling process, with the aim of turning the company into an entirely circular business.
"I would like by 2030, for us to be viewed as the industry standard battery for stationary energy storage, in the same way that lithium-ion presently is. I would like us to have giga-factories on at least two continents so that we can be shipping at volume," Brown said.
"I would like us to have reduced costs of energy storage enough so that we can make renewable energy plus batteries the cheapest market-preferred option, because that's what you need to get people to stop building coal and gas plants."