Abstract: Provided is an electrochemical device having an electron source and a hydrogen peroxide solution for reaction to accept the electrons, the device with an anode compartment and a cathode compartment, including (a) a cathode electrode having an area, which can be adjustable, in contact with the cathode compartment of AC; and (b) an anode electrode having an area, which can be adjustable, in contact with the anode compartment of AA, wherein either the cathode or anode electrode area or both are adjustable, such that AC/AA=EAR is adjustable, and wherein, where jEC is the anode current provided by the electron carrier, and jTOS is a diffusion-limited current density for a reaction by oxygen in an oxygen saturated said hydrogen peroxide solution, EAR is selected such that either

Abstract: Still further provided is a fuel cell with an anode compartment and a cathode compartment comprising: in the anode compartment, an anode electrode and, integrated into biocompatible membrane tethered to the anode electrode, a redox enzyme that can receive electrons from an electron carrier; in the cathode compartment, a cathode electrode which, when a conductive pathway to the first electrode is formed, is effective to convey the electrons to an electron acceptor composition in the cathode compartment; and a barrier separating the anode compartment from the cathode compartment but effective to convey protons from the anode compartment to the cathode compartment.

Abstract: In one embodiment, provided is a fuel cell with an anode compartment and a cathode compartment comprising: in the anode compartment, an anode electrode and one or more dehydrogenase enzymes effective to transfer electrons from a C1 compound comprising carbon, oxygen and hydrogen (optionally consisting of carbon, oxygen and hydrogen) to electron carrier(s), and wherein or further comprising one of the following:

Abstract: Also provided is a fuel cell system comprising (1) a fuel cell with an anode compartment and a cathode compartment adapted to operate with a least one liquid consumable comprising (i) a liquid fuel composition or (ii) liquid electron acceptor composition, and: (2) one or both of (a) a fuel reservoir comprising liquid fuel composition separated from the anode compartment by a porous membrane that is selected to not be wetted by either the liquid fuel composition or a solvent/solution with which the anode chamber is adapted to operate or (b) a liquid fuel composition reservoir separated from the cathode compartment by a porous membrane that is selected to not be wetted by either the liquid fuel composition or a composition with which the cathode chamber is adapted to operate.

Abstract: The present invention relates to a biocompatible membrane, solutions useful for producing a biocompatible membrane and fuel cells which can utilize biocompatible membranes produced from a synthetic polymer material consisting of at least one block copolymer and optionally at least one additive and a polypeptide.

Abstract: Additionally provided is a fuel cell with an anode compartment, a cathode compartment and a barrier separating the anode compartment from the cathode compartment but effective to convey protons from the anode compartment to the cathode compartment, comprising in the anode compartment, one or more anode electrodes and, one or more dehydrogenase enzymes effective to transfer electrons from a C1 compound to electron carrier(s), wherein one or more of the said enzyme(s) are covalently linked to surface(s) within the anode compartment.