“…Electrical energy can be produced upon electrochemical oxidation of biomolecular species (e. g., glucose) at an anode and oxygen reduction at a cathode of biofuel cells, like MFCs, [36,51,52] EFCs [8,33,34,[53][54][55][56][57][58][59][60] and abiotic bioelectrochemical devices. [38] Their main feature is the operation in a biological environment and power generation from biological materials. Most of designed biofuel cells, in particular EFCs, are producing micro-scale electrical power.…”