Using ferrous-oxidizing bacteria to enhance the performance of a pH neutral all-iron flow battery

Sitao Li; Sen Fan; Xinyuan Peng; Decong Zheng; Daping Li

doi:10.1016/j.isci.2023.108595

Using ferrous-oxidizing bacteria to enhance the performance of a pH neutral all-iron flow battery

iScience. 2023 Nov 29;27(1):108595. doi: 10.1016/j.isci.2023.108595. eCollection 2024 Jan 19.

Authors

Sitao Li^{1

2}, Sen Fan^{1

3}, Xinyuan Peng^{1

3}, Decong Zheng^{1

2}, Daping Li^{1

2}

Affiliations

¹ Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Science, Chengdu 610041, China.
² University of Chinese Academy of Sciences, Beijing 100049, China.
³ Collage of Life Sciences, Sichuan University, Chengdu 610041, China.

Abstract

Among various redox flow batteries (RFBs), the all-iron RFBs have greater application potential due to high accessibility of electrolytes. However, the potential of microaerobic ferrous-oxidizing bacteria (FeOB) to improve the performance of RFB has been neglected. Here, several experiments were conducted using Fe²⁺-diethylenetriaminepentaacetic acid (DTPA)/Na₃[Fe(CN)₆] as a redox couple for investigating the enhanced performance by FeOB in this RFB. Results showed that the maximum current density of experimental reactors could achieve 22.56 A/m² at 0.1 M, whereas power density could still maintain 3.42 W/m²(16.96 A/m² and 1.58 W/m² for control group); meantime, the polarization impedance of anode increased slower and Fe²⁺-DTPA oxidation peak emerged maximum 494 mV negative shift. With increased electrolyte concentration in chronopotentiometry experiments, the experimental reactor achieved higher discharging specific capacity at 0.3 M, 10 mA/cm². Microbial composition analysis showed maximum 75% is Brucella, indicating Brucella has ferrous-oxidizing electroactivity.

Keywords: Applied sciences; Energy storage.