![\"\"](\"https:\/\/www.europesays.com\/ie\/wp-content\/uploads\/2025\/10\/stanford.jpg\" "\\"Iron")
<\/a>(Front row, from left): Eder Lomeli, Edward Mu, and Hari Ramachandran. Credit\u2013 Bill Rivard\/Stanford<\/p>\nThe team realized the solution was to make the material\u2019s particles extremely small. \u201cMaking the particles very small \u2013 just 300 to 400 nanometers, or billionths of a meter, in diameter, about 40 times smaller than before \u2013 turned out to be a challenge,\u201d said Ramachandran.<\/p>\n
Eventually, the duo figured out how to grow their crystals from a carefully mixed liquid solution. <\/p>\n
\u201cIn our electrochemical tests, the material seemed to get iron to reversibly give up and later take back five electrons while the crystal structure remained stable,\u201d Mu said.<\/p>\n
To verify what was happening inside, Lomeli teamed up with his advisor, Tom Devereaux, who specializes in modeling X-ray spectra. <\/p>\n
Lomeli\u2019s analysis confirmed that the additional electrons were not just coming from the iron atoms alone but with crucial help from oxygen. <\/p>\n
\u201cIt\u2019s too simple to say that iron is the hero or oxygen is the hero,\u201d he said. \u201cThe atoms in this very nicely arranged material behave like a single entity.\u201d<\/p>\n
The new iron age<\/p>\n
Iron\u2019s comeback in battery science marks a turning point. Once dismissed as too low-voltage for advanced energy storage, iron-based cathodes are now emerging as sustainable alternatives to cobalt, which is expensive and often mined under hazardous conditions.<\/p>\n
\u201cA high-voltage, iron-based cathode could avoid the tradeoff between higher voltage and higher-cost metals that previously dominated cathode materials,\u201d Mu said.<\/p>\n
The idea traces back to 2018, when former Stanford PhD student William Gent theorized that iron could be pushed to higher oxidation states if neighboring atoms were carefully spaced apart. Gent never got the chance to complete the experiment, but the new team did.<\/p>\n
At Stanford\u2019s SLAC-Stanford Battery Center, early tests showed that the lithium<\/a>\u2013iron\u2013antimony\u2013oxygen compound stayed structurally intact, bending slightly rather than breaking during charge cycles<\/a>.<\/p>\n \u201cScientists have rarely reported high-voltage iron-based materials,\u201d said co-lead author William Chueh. \u201cOur detailed electronic structure exploration of this iron species provides conclusive evidence of oxidation beyond three electrons.\u201d<\/p>\n