Korea Advanced Institute of Science and Technology (KAIST) last week said it has developed a new material that enhances the energy density of lithium-ion batteries by 20 per cent while maintaining their stability.
According to a research project led by Cho Eun-ae (pictured, KAIST), materials science and engineering safety professor at KAIST, lithium-ion batteries that contain 80 per cent nickel inside cathodes demonstrate energy capacity of 200 ampere-hours per gramme.
However, the newly developed cathode materials can accommodate 20 per cent more lithium ions and exhibit energy capacity of as much as 250 ampere-hours per gramme.
Cathodes are one of the four key components of lithium-ion batteries including anodes, separators and electrolytes. The higher the ratio of nickel inside cathodes, the more powerful but less stable lithium-ion batteries become.
Cho told The Korea Herald: “If existing high-nickel cathodes could accommodate 100 lithium ions, the new cathodes can contain 120 lithium ions, providing greater energy to batteries.”
She added that lithium-rich cathodes haven’t been commercialised yet because when too much lithium-ions visit cathodes, they react with oxygen and compromise the structure of the cathodes.
However, Cho solved the instability issue by coating the lithium-rich cathodes with a metal called vanadium.
According to the research, lithium-ion batteries coated with vanadium maintained 92 per cent of initial performance after charged and discharged 100 times, while uncoated ones preserved 74 per cent of initial capacity.
Also, cathodes coated with vanadium returned to their original state at 81 per cent level after charged and discharged once, while uncoated cathodes recovered their original state at 69 per cent level in the same condition.
Cho said: “Vanadium is not a common material, but as a extremely small amount is used for coating cathodes, it’s unlikely to drive up the costs of lithium-ion batteries.”
THE KOREA HERALD/ASIA NEWS NETWORK