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8 June 2022

E-Zinc reaches starting gate for alternative battery chemistries

Canada’s alternative chemistry battery e-Zinc says it will do a pilot with Toyota Tsusho Canada (TTC) to validate its technology on a commercial scale.

e-Zinc claims that it is suitable for really long-duration energy storage and this project is supposed to validate the e-Zinc ability to store energy for at least 24 hours, and as long as 3 days.

Any commercial deal of any size right now for battery technologies which are immune from thermal runaway are of interest, but this deal seems to be a pilot, therefore it is not quite yet of significant commercial scale.

Rethink has identified that alternative battery chemistries have a 3 to 4  year window to get into production, scale and drive down their average cost of manufacture. This should make them reliably below the cost of lithium ion batteries, even once the current cathode materials crunch in lithium is over. Right now the Electric Vehicle industry needs every battery that it can make, with few to spare to support the electricity grid, until around 2027, by which times US battery supply chains and manufacturing plants will catch up the slow start the US car-makers made to EV adoption.

It is ironic that e-Zinc has cut this deal with part of the Toyota group, the Japanese car company that did the least to see lithium ion adoption embraced in powering passenger cars. Toyota has waged a multi-decade campaign to use hydrogen for zero emissions cars, and even today is only embracing hybrid EV technology for the most part.

This contract is described as a “paid validation,” by which we understand that the project is being paid for by Eurus Energy America as a pilot built by TTC, and using e-Zinc storage technology. It will store wind energy at the Eurus Bull Creek wind farm in Texas, storing excess wind generation which can then be used to power buildings. This technology is being described as “better suited” to the intermittency of wind generation than typical batteries.

What is precisely meant by that is unclear – wind has a higher capacity factor than solar – in the sense that it CAN run for 24/7 while solar cannot (except in space). Lithium ion batteries are used with solar on the understanding that SOME of the solar goes to batteries to be discharged once it gets dark. In the case of Wind, the speed of a turbine can vary and therefore so can its output, but there is not a ten hour plus period when no energy is produced at all.

What CAN happen with wind however is that for a long period of time, for instance 3 or 4 days, it can deliver sub-optimal power, and flip flop from actively charging to discharging multiple times, throughout a period of low wind. So a battery must both discharge and charge at the same time, and not simply have a full lengthy once a day discharge. Many lithium ion batteries are sold with warranty conditions that they must only be fully cycled once a day – which might make them unsuitable for partnering with wind resources. If e-Zinc can PROVE this is the case commercially, it would open the door to significant orders from Wind only renewables firms, allowing them to trade their electricity at a higher value.

At present wind tends to have to operate at a remove from energy storage, since wind is produced as alternating current, and storage works with direct current, and there has to be an inverter between the two. As a result solar partners work well with battery, and commercially the two have set up at arms-length, so that typically spare wind energy has to be sold to the battery owners at cut down prices.

This pilot will run in spring 2023, at the same time as another e-Zinc demonstration project, it has with the California Energy Commission. This was when it won a $1.3 million grant to demonstrate its battery with a view to it being used for clean backup power during wildfires.

The e-Zinc battery precipitates tiny pieces of zinc out of its Zinc di-hydroxide (also called zinc dehydrate) electrolyte solution as it charges. It uses something analogous to a windshield wiper to brush off the pellets to fall into a lower chamber ready to be used for discharge.

The electrolyte is shown as having this chemical formula Zn(OH)24 called zinc di-hydroxide

And the battery is said to allow all components to be recycled on an existing recycling market, no likelihood of thermal issues, given a non-flammable electrolyte, it operates over a wide range of temperatures, and needs no power supply to trigger the discharging process. Although e-Zinc says the system has a “long” lifetime, there are no details of how many charge discharge cycles it can survive, so until it verifies that, we can’t be entirely sure.

E-Zinc also boasts that the technology costs considerably less than lithium ion. But in any early instance a finished battery will be hand-made and cost considerably more than lithium ion, and the challenge for this technology is to scale to a multi-GW gigafactory in this 2 to 3 year window we see where lithium ion will be overly expensive for grid energy storage.

The Toyota connection was made when last month Toyota Ventures was one of the investors in a $25 million Series A round for e-Zinc, with funding from BDC Capital, Toyota Ventures, and Eni Next and existing seed investors Energy Foundry.

e-Zinc believes its sweet spot market is to displace diesel generators for between a half-day and a five-day backup power use case.

It is tough to make a pronouncement on a technology like this, beyond saying it is promising, but very late to the party. There are probably 4 or 5 opportunities worldwide for non-lithium ion chemistries for on grid energy storage, but all of them need to be producing in GWh capacities before 2025/6 in order to make it. At present 99% of grid energy storage projects are lithium ion, but with a huge shortfall in battery materials and ready factories, especially in the US, we expect this to fall perhaps as low as 50% in this interim period, before rising again.

Once lithium-ion dominates EV charging and EVs are the dominate style of car being delivered, it could get over its thermal runaway problems, either transitioning to LFP or to solid state lithium ion. At that point only a technology that is already in manufacture and which is already cheaper than lithium ion, will still hold investor interest. E-Zinc needs to begin thinking about a high volume automated factory as soon as these pilots are completed, and certainly before the end of 2024.

e-Zinc is not the only Zinc battery maker around. The better known Eos Energy Enterprises from New Jersey recently secured another $200 million of investment with a similar zinc-air battery and expects to have $50 million in revenues in 2022, a 10x rise from 2021. It is expanding production facilities at its site near Pittsburgh to 800MWh annual capacity with a $25 million spend. The only advantage that e-Zinc has over this is that it actually stores the energy as Zinc metal, which can remain in that state indefinitely, without losing charge. Eos Energy continually plates and replates zinc electrodes creating a 3-hour duration battery, however those modules can be stacked together to create up to around 12 hours of storage in a complete system. It has already gone public through the now highly unpopular SPAC route.

It spent $140 million in 2021, but has an order backlog of $150 million and has been invited by the US Department of Energy (DoE) to apply for loans to fuel its manufacturing expansion and it has a single deal with Hecate Energy for “more than 1GWh” of its aqueous zinc chemistry battery worth around $250 million.

As we are fond of saying, the best technology rarely wins. Instead that honor goes to the best funded, which arrives at the right place in the right time, with the right partners. Either way e-Zinc is just about in the race, for now.