The Institute of Metal Research at Chinese Academy of Sciences, has developed a 6,000 cycle iron battery with super-stable electrolyte. The key to this development is a ‘novel iron-complex electrolyte’ that allows the alkaline all-iron flow battery to retain its capacity over thousands of cycles.
This advance, the media release we link to below continues, addresses a long-standing bottleneck in low-cost, long-duration energy storage. This could be an opportunity that we have been waiting for, to advance grid-scale renewable energy.
Why This 6,000 Cycle Iron Battery Matters
The transition to renewable energy cannot complete without long life, low cost, and safe energy storage. Alkaline all-iron flow batteries have potentially offered a possible solution, because the total energy they store is independent of the power they put out.
However, this promise has not come true until now, because the chemistry does not cycle well. And moreover, the ions do not flow efficiently and the battery breaks down during the early phases of operation.
The team from the Institute of Metal Research say they have overcome these obstacles, with their ‘ultra-stable iron complex electrolyte’. We understand that this material slows the chemical reactions, thanks to a negatively-charged interface. See the link to Wiley below for the full scientific report.
How They Found Their ‘Ultimate’ Iron Battery
The researchers synthesized eleven iron complexes in their area of interest. They then zoomed in on the one offering the optimum blend of structural strength, coupled to a negatively-charged interface.
This combination prevented the hydroxide ions from attacking the iron core, and breaking it down. It also prevented free ions from crossing the membrane. This in turn resolved the problem of electrolyte contamination and degradation.
This combination worked a treat! Their 6,000 cycle iron battery retained its capacity thanks to 99.4% coulombic efficiency. This research charts a way forward for iron-based electrolytes. As such, it appears to offer a promising solution for large-scale energy storage.
More Information
Coulombic Efficiency in Batteries Unpacked
Paraffin Binder For Electrode Interfaces
Preview Image: Alkaline All-Iron Flow Battery
