Dave Borlace delivers a counterintuitive verdict on a technology many assumed was dead: the zinc bromine flow battery is not only alive but undergoing a fundamental chemical resurrection in China. While Western startups have collapsed under the weight of engineering realities, Borlace argues that a breakthrough in electrolyte chemistry from the Dalian Institute of Chemical Physics has finally solved the decades-old corrosion problem that doomed the sector. This is not just a minor efficiency tweak; it is a potential game-changer for long-duration energy storage that could redefine the economics of renewable grid balancing.
The Valley of Death and the Chinese Pivot
Borlace begins by grounding the reader in the recent failures of the sector, specifically citing the Australian company Redflow. He notes that despite high hopes, "the batteries were beset with reliability issues and Red Flow found themselves spending more time and money fixing customers units under their warranty terms than they did on actually developing and improving the system." This failure, he argues, was a classic case of a startup falling into the "valley of death between technology breakthrough and real world implementation." The narrative here is effective because it acknowledges the genuine difficulty of the chemistry rather than dismissing the technology as a failed concept. It sets the stage for why a simple hardware fix wasn't enough.
The core of the piece shifts to the specific chemical hurdle: bromine. Borlace explains that while zinc bromine batteries offer double the energy density of traditional vanadium systems, they suffer from "the production of corrosive elemental bromine during charge." This corrosive element eats away at membranes and forces the use of expensive materials like titanium and fluorinated membranes. The author's analysis is sharp here; he identifies that the problem wasn't the energy potential, but the material science required to contain the reaction. "That corrosion limits cycle life and forces designers to use expensive corrosion resistant materials... which drives up cost and reduces commercial appeal," he writes. This is the critical bottleneck that has kept the technology from scaling.
A Fundamental Chemical Breakthrough
The commentary turns to the solution proposed by researchers at the Dalian Institute. Instead of building stronger hardware to withstand the corrosion, the team changed the chemistry itself. Borlace highlights the elegance of this approach: "Instead of allowing bromide ions to be converted to free elemental bromine, the researchers introduce what they describe as amine-based bromine scavengers into the electrolyte." These scavengers react instantly with the bromine, creating stable compounds that do not corrode the system. The result is a system that maintains its high energy density while eliminating the need for costly, exotic materials.
"That's the sort of advancement that doesn't just make one prototype a bit better. It's more your fundamental breakthrough type stuff that could open up a whole new design space."
This quote captures the significance of the innovation. The author emphasizes that this is a mechanistic fix, addressing the root cause rather than the symptoms. The evidence provided—a 5 kW demo system running over 700 stable cycles with 78% efficiency using inexpensive non-fluorinated membranes—is compelling. However, critics might note that laboratory success does not guarantee industrial scalability. The jump from a controlled lab environment to a rugged, containerized unit that must operate reliably for decades in diverse climates is a massive leap that often stymies even the most promising chemistries.
The Industrial Ecosystem Advantage
Borlace's most distinctive insight lies in his analysis of who is best positioned to commercialize this discovery. He points out that while Western firms have pivoted away or gone bankrupt, a Chinese firm named Junan Energy remains active in the space. "Unlike most of the Western players that have either pivoted away from zinc bromine or disappeared entirely, Jinan is still actively developing and manufacturing zinc bromine flow batteries," he observes. The author argues that the Chinese ecosystem, where research institutes and manufacturers are tightly integrated, offers a distinct advantage in translating lab results into commercial products.
The piece suggests that Junan Energy could leverage this new chemistry to "strip out those expensive corrosion resistant components, boost energy density, and offer a genuinely competitive longduration storage solution at lower cost." This reframing moves the story away from a simple technology update to a broader discussion on global supply chains and industrial policy. The author notes that "the ecosystem in China is far more intertwined than what we're used to in the West," suggesting that the speed of technology handoff is a structural advantage. This is a crucial point for readers to consider: the future of energy storage may depend less on the initial discovery and more on the industrial capacity to deploy it.
The Role in the Global Grid
Finally, Borlace contextualizes where this technology fits in the broader energy landscape. He distinguishes zinc bromine flow batteries from iron-air batteries, which target multi-day storage, and lithium-ion, which dominates short-duration needs. "Bromine flow batteries are shooting for a slightly different sweet spot though. 4 to 12 hours, high cycle life, and safe operation in harsh conditions," he writes. They are positioned as the "workhorses for daily cycling, renewables balancing, and industrial micro grids." This clarity on the use case is vital; it prevents the reader from expecting this technology to replace batteries in electric vehicles or smartphones.
"If companies like Gennine Energy decide to pick up the batn, and if these ideas survive the brutal transition from lab bench to shipping container, then zinc bromine flow batteries could yet have a very respectable second act."
The author's tone remains cautiously optimistic. He acknowledges that "no champagne and party hats just yet" because the technology is still in the lab phase. Yet, the argument that the underlying chemistry's biggest weakness has been solved is a strong one. The piece effectively argues that the failure of Redflow was a business and scaling issue, not a fundamental flaw in the zinc bromine concept.
Bottom Line
Dave Borlace's strongest argument is his identification of a fundamental chemical solution to the corrosion problem that has plagued zinc bromine batteries for decades, shifting the narrative from failure to potential revival. The piece's biggest vulnerability is the assumption that the seamless integration of Chinese research and manufacturing will automatically translate to global commercial success, overlooking potential geopolitical barriers or supply chain friction. Readers should watch closely to see if Junan Energy can successfully scale this lab breakthrough into a rugged, cost-competitive product within the next few years.