Cheap nickel-cobalt electrode cuts hydrogen material costs by 99%

South Korea's KIER developed a platinum-free nickel-cobalt electrode for alkaline water electrolysis. It matches commercial hydrogen output at 22.7 mV overpotential versus 56.5 mV for platinum systems and survived 600 start-stop cycles.

• Nickel and cobalt cost $0.02 and $0.05 per gram versus about $58 per gram for platinum
• Overpotential of 22.7 mV is roughly 40% of the 56.5 mV needed by commercial platinum electrodes
• In an 8.7 cm cell, voltage dropped 11% and the electrode survived 600 start-stop cycles
• 40 cm electrodes have been made, with a target of 5,000 cm² for megawatt-scale plants