Study of voltage reversal of stacked sediment microbial fuel cells

Abstract

Sediment microbial fuel cell (SMFC) is a renewable energy source with a wide range of raw materials. They have a simple structure, low cost, and broad application prospects in the field of self-power supply, attracting the attention of many researchers. However, the output current of SMFC is weak and the output voltage is low, which does not meet the power supply requirements of general electronic devices. Therefore, it is necessary to connect multiple SMFCs to obtain the required voltage and current. Series operation can increase the output voltage, while parallel operation can increase the output current. However, voltage reversal occurs in series operation, which can affect the output performance of the battery. In this work, voltage reversal was studied by two SMFCs respectively connected in series and in parallel after their output voltage stabilized. External load of the series and parallel batteries were connected to 330 ohms, 680 ohms, 1000 ohms, 2000 ohms, and 380K ohms, respectively. It was found that batteries with poor performance in series battery packs experienced voltage reversal, which occurred at 330 ohms, 680 ohms, and 1000 ohms. When the resistances became 2000 ohms and 380K ohms, parallel battery packs did not experience similar phenomena. The reason for voltage reversal was provided in this article. In addition, voltage reversal occurred in the stage of low resistances, which indicating that the greater the current, the greater the possibility of voltage reversal.