Enzymatic glucose/oxygen biofuel cells: Use of oxygen-rich cathodes for operation under severe oxygen-deficit conditions

A glucose/oxygen biofuel cell (BFC) that can operate continuously under oxygen-free conditions is described. The oxygen-deficit limitations of metabolite/oxygen enzymatic BFCs have been addressed by using an oxygen-rich cathode binder material, polychlorotrifluoroethylene (PCTFE), which provides an internal oxygen supply for the BFC reduction reaction. This oxygen-rich cathode component mitigates the potential power loss in oxygen-free medium or during external oxygen fluctuations through internal supply of oxygen, while the bioanode employs glucose oxidase-mediated reactions. The internal oxygen supply leads to a prolonged energy-harvesting in oxygen-free solutions, e.g., maintaining over 90% and 70% of its initial power during 10- and 24-h operations, respectively, in the absence of oxygen. The new strategy holds considerable promise for energy-harvesting and self-powered biosensing applications in oxygen-deficient conditions.