EV range doubled: Toyota’s solid-state battery cathode beats lithium in energy density
Researchers focused on copper nitride (Cu3N) as a cathode material for all-solid-state fluoride-ion batteries.
Researchers, in collaboration with Toyota Motor Corporation, have worked on a new type of cathode material for all-solid-state batteries. They have reportedly improved the capacity per volume of the positive cathode for “all-solid-state fluoride ion batteries” to about three times that of lithium-ion batteries.
Reports revealed that when incorporated into a battery, it’s expected to have 2x more energy density than lithium-ion batteries.
The cathode material for all-solid-state fluoride-ion batteries (FIBs) delivers a reversible capacity of approximately 550 mAh/g. That’s more than double the 120–250 mAh/g typical of lithium-ion cathodes, according to a report.
Fluoride-ion battery to be part of practical EVs
The fluoride-ion battery is expected to be part of the practical use for EVs after a few years.
Researchers from Kyoto University use copper nitride in the cathode. Other materials, such as manganese and lanthanum, are also used in a perovskite crystal. Fluoride ions move through NaCl slabs during the charging process.
They revealed that the copper nitride reacts with nitrogen and fluoride ions, making it possible to extract three electrons per nitrogen atom. This gives it three times the capacity per volume and twice the capacity per weight of lithium-ion batteries. It is also said to be durable enough to withstand dozens of charge/discharge cycles.
Researchers stressed that all-solid-state fluoride-ion batteries (FIBs) have attracted extensive attention as candidates for next-generation energy storage devices; however, promising cathodes with high energy density are still lacking. Its use in solid-state batteries can double the driving range of electric vehicles (EVs) from 600 km (372 miles) to 1,200 km (745 miles).
Fluoride-ion batteries offer next-generation energy storage
Reports revealed that in recent years, fluoride-ion batteries have gained in popularity, given their potential in next-generation energy storage.
That’s in large part a result of their potential for improved safety given the presence of solid electrolytes and fast fluoride ion conduction. Fluoride ions, being monovalent and small, move quickly in solids. However, previous fluoride-ion cathodes had limitations. This new Cu₃N material appears to address multiple issues.
Published in the journal American Chemical Society, the study investigated copper nitride (Cu3N) as a cathode material for all-solid-state fluoride-ion batteries, which offers enough anionic vacancies around the 2-fold coordinated Cu center for F– intercalation, thereby enabling a multielectron-transferred fluorination process.
Researchers revealed that Cu3N exhibits a high reversible capacity of ∼550 mAh g–1, exceeding many conventional fluoride-ion cathodes. It is believed that the new charge compensation chemistry, as well as the unique intercalation behaviors of novel mixed-anion Cu–N/F local structures, could bring new insights into energy storage materials.
The cathodes developed in this study are also suitable for the next generation of all-solid-state fluoride-ion batteries. To develop an all-solid-state fluoride-ion battery, in addition to the positive electrode, an anode, and a solid electrolyte are required, and the research group will continue to develop these separately, reported Nikkei.
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EV range doubled: Toyota’s solid-state battery cathode beats lithium in energy density, source
