Inlyte Energy's iron-sodium battery combines high-performance daily cycling (4–10 hours) and low-cost long-duration storage (24+ hours)

https://www.prnewswire.com/news-releases/inlyte-energy-announces-milestone-achievement-in-iron-sodium-battery-technology-delivering-breakthrough-results-for-long-duration-energy-storage-302323240.html

"safe, durable, scalable, stable cycling in commercial-size cells, also for computers... >700 cycles with no loss in energy capacity,  90% roundtrip efficiency, using iron-sodium in sodium metal chloride cell... > 7K cycles battery life or 20 years, matching traditional sodium nickel chloride batteries, but at fraction of cost... proprietary iron cathode/ optimized operating conditions... replacing nickel with cheaper iron... targeting commercial demonstration projects in 2025 and large-scale U.S. manufacturing by early 2027"