Frontline
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Redflow’s Revolution
How an Aussie company is looking to jumpstart the battery industry. By Bennett Ring ASM Correspondent
28 | Asia Pacific Security Magazine
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n 2018, South Australia’s sustained support for renewable energy has reached widespread attention both nationally and globally, largely in part to the Hornsdale power reserve. Thanks to its partnership with Tesla to provide the world’s largest lithium-ion battery, it’s been credited with stabilising the state’s power grid after several years of less than perfect performance. However, there’s an alternate battery technology being promoted by a prominent South Australian, offering several key benefits compared to lithium-ion. Redflow is a Brisbane-based company who just happens to have Simon Hackett as one of the key backers. As the founder behind ISP Internode, former NBN board member and the owner of the first Tesla Roadster and Tesla Model S electric vehicles in Australia, Mr Hackett has built an enviable reputation as one of Australia’s most accurate weathervanes when it comes to emerging technologies. Mr Hackett was the CEO of Redflow until September 2017, but is still its largest single investor, as well as a non-executive director and technology evangelist for the company. Redflow specialises in zinc-bromine flow batteries, and currently sells two different versions, the ZCell for residential use and the ZBM2 for industrial and commercial applications. It’s not the only company in the world to make batteries based on this technology, but its real breakthrough has been in miniaturising the size of these units. We recently
interviewed Mr Hackett after a keynote he presented at the Australian Energy Storage Conference, to understand why he’s become such an energetic proponent of this new battery technology. In the past, zinc-bromine flow batteries were around the size of shipping containers, but Redflow has managed to shrink them to the size of a small bar fridge, making them perfect for home use. The ZCell battery has a capacity of 10 kWh, with no loss in storage capacity for a decade, no matter how many times it is charged and discharged, a huge advantage over traditional lithium-ion batteries. When we asked how Redflow managed to achieve this miniaturisation, Mr Hackett explained that this was the primary task the founders set out to achieve. “The electrode stack they designed embeds a complex set of electrolyte fluid flow handling into moulded plastic structures built right into the edges of the same plates on which the electrochemical reactions occur. Those plates are then sandwiched together and sealed so all the complex fluid flow ‘plumbing’ that is ‘external’ (and vulnerable) on conventional (big) flow batteries is internalised - and invulnerable - in ours.” They’re able to maintain their long-term life by flushing the zinc off the plates and returning it to the zinc bromide solution every three to four days. There’s a drawback to this in that each battery must do a full discharge every four days