New “all-iron” battery promises exceptional durability for a fraction of the price

Lithium batteries power almost everything from smartphones and cordless tools to electric cars. Although large reserves of the raw material indicate that we will not run out of this material anytime soon, lithium remains an expensive commodity. In mid-May 2026, its price hovered around the calculated 23,850 euros per ton. On the other hand, there are much cheaper metals available, such as iron ore, which costs just over 100 euros per ton and is an excellent base for more affordable batteries.

Scientists at the Institute of Metals Research (IMR) of the Chinese Academy of Sciences have developed a special “all-iron” flow battery. According to the research, the new system can withstand 6,000 charging cycles, which is about 16 years of daily use, without losing any of its original capacity. For comparison, a typical lithium-ion battery in a smartphone can withstand less than 1,000 cycles, while larger systems can achieve up to 5,000 cycles.

Flow batteries differ from traditional batteries in that their key elements are immersed in a liquid electrolyte. Chinese researchers have used a new electrolyte that successfully prevents hydroxide ions from attacking the iron core. This protection of the core solves the problems of rapid degradation and short lifespan that have plagued all previous similar attempts.

The researchers report that their iron battery achieved an average efficiency of 99.4 percent over 6,000 cycles at a current of 80 mA/cm². This efficiency measures the efficiency of electron transfer between electrodes during charging. The device also performed well at higher currents, maintaining an efficiency of 78.5 percent at 150 mA/cm². High values of this efficiency are directly related to longer lifespan, confirming the enormous potential of this technology.

Despite the impressive results, we won't see these batteries in portable electronics. The technology is designed for long-term energy storage in large electrical grids and will play an important role in the transition to renewables. Similar large-scale flow-through systems are already operating in Japan and China, and in the US, Ess Tech Inc is equipping the New Horizon project with a 5-megawatt, 50-MWh capacity, enough to power more than 1,000 homes for 10 hours. Time will tell whether the new Chinese technology will see similar mass adoption.