A team of researchers has developed a prototype glucose flow battery – a type of flow cell powered by glucose and vitamin B2 (riboflavin) – that mimics the way the human body metabolises sugar to generate energy.
Reported in ACS Energy Letters, the study demonstrates how riboflavin can act as a mediator to shuttle electrons between electrodes and a glucose-based electrolyte, generating electrochemical flow from naturally derived energy.
“Riboflavin and glucose flow cells can generate electricity from naturally derived energy sources,” said lead author Jong-Hwa Shon. “Using non-toxic components that are both inexpensive and naturally abundant, this system offers a promising pathway toward safer and more affordable residential energy storage.”
Flow cell batteries store energy in two circulating electrolytes. As reactions occur, chemical energy is converted to electricity. Glucose, found in most plants, offers a low-cost and abundant electrolyte option. Traditional glucose fuel cells rely on noble metal catalysts, which are difficult to scale. Riboflavin, however, is stable at the basic pH required for glucose flow cells and presents a viable alternative.
The team used carbon electrodes and tested two electrolyte configurations: one with potassium ferricyanide and another with oxygen. While the ferricyanide cell allowed precise measurement of riboflavin’s catalytic activity, the oxygen-based cell proved more cost-effective for scale-up, despite slower reactions due to riboflavin degradation in light.
The glucose flow battery researchers plan to improve the oxygen cell’s power density through enhanced cell engineering and light shielding.
Image: A new riboflavin and glucose flow battery generates a greater power density from the sugar than previous designs. Credit: Nathan Johnson, Adapted from ACS Energy Letters 2025, DOI: 10.1021/acsenergylett.5c02462
