Researchers at Xi’an Jiaotong University in China have developed a Na-ion direct formate fuel cell to co-produce electricity and hydrogen (e-h₂ Na-DFFC). A paper on their work is published in the Journal of Power Sources.

Using formate—a solar fuel that can be readily synthetized from carbon dioxide—the researchers reported that a proof-of-concept e-h₂ Na-DFFC yielded a peak power density as high as 168 mW cm⁻² at 380 mA cm⁻², with the hydrogen production rate reaching 2.9 mL min⁻¹ cm⁻².

More importantly, the approximate 100% purity and over 98.9% Faradic efficiency suggest the great potential of this electricity-hydrogen co-production device. … This proposed e-h2 Na-DFFC provides a new pathway for renewable hydrogen production.

—Sun et al.

The hydrogen that is produced from the e-h₂ Na-DFFC can be directly fed to hydrogen-oxygen fuel cell, which presents a peak power density of 546 mW cm⁻² and 35 hours of stable operation at room temperature.

Resources

• Xianda Sun, Yuxuan Lou, Ya-Ling He, Yinshi Li (2021) “A Na-ion direct formate fuel cell converting solar fuel to electricity and hydrogen,” Journal of Power Sources, Volume 499 doi: 10.1016/j.jpowsour.2021.229960