Super‐fast Charging Biohybrid Batteries through a Power‐to‐formate‐to‐bioelectricity Process by Combining Microbial Electrochemistry and CO2 Electrolysis

Abstract Extensive study on renewable energy storage has been sparked by the growing worries regarding global warming. In this study, incorporating the latest advancements in microbial electrochemistry and electrochemical CO 2 reduction, a super‐fast charging biohybrid battery was introduced by using pure formic acid as an energy carrier. CO 2 electrolyser with a slim‐catholyte layer and a solid electrolyte layer was built, which made it possible to use affordable anion exchange membranes and electrocatalysts that are readily accessible. The biohybrid battery only required a 3‐minute charging to accomplish an astounding 25‐hour discharging phase. In the power‐to‐formate‐to‐bioelectricity process, bioconversion played a vital role in restricting both the overall Faradaic efficiency and Energy efficiency. The CO 2 electrolyser was able to operate continuously for an impressive total duration of 164 hours under Gas Stand‐By model, by storing N 2 gas in the extraction chamber during stand‐by periods. Additionally, the electric signal generated during the discharging phase was utilized for monitoring water biotoxicity. Functional genes related to formate metabolism were identified in the bioanode and electrochemically active bacteria were discovered. On the other hand, Paracoccus was predominantly found in the used air cathode. These results advance our current knowledge of exploiting biohybrid technology.