Stacking and design optimization of novel plant microbial fuel cell based on dwarf indoor decorative and culinary plants as a compact biobattery for a low energy consumption devices

Abstract

This article presents the development of a novel compact plant microbial fuel cell (PMFC) constructed with discarded food packagings as a stand-alone power supply for low-power devices suitable for indoor use in real time. A two-modular PMFC with 0.6 L-capacity units with multi-electrode system, connected in parallel inside and joined in series outside, provided power for a 1.5 V, 4.3–105.2 mkA digital thermometer/hygrometer, and a three-modular PMFC ensured operation of a 3 V, 10.1–36.4 mkA weather station or LEDs during the year of the experiment. PMFC with a shortened (1 cm) electrode distance and increased cathode surface area (cathode:anode ratio 1.5:1) using H. soleirolii were characterized by higher bioelectricity output. The maximal current and power density were 407 mA/m2 and 188.33 mW/m2, respectively. Stacking of PMFC modules by combining parallel-series connection with reduction of the interelectrode distance and adjusting the electrodes area is a promising way to improve bioelectricity output for development of compact biobatteries.