Methods and devices for generating electricity from a fuel and an oxidant using a capacitor

Abstract

Devices and methods are provided for generating electrical power using a capacitor. The capacitor has a catalytic working electrode, a dielectric, and a counter electrode. Power is generated by flowing a fuel (e.g., hydrogen gas) over the working electrode, charging the capacitor (e.g. by applying a voltage), flowing an oxidant (e.g., oxygen gas) over the working electrode, and connecting the electrodes to a resistive load, which allows current to flow through the load, between the electrodes. The inverse device (i.e., oxidant first, then fuel) functions similarly.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 
     
         1 . A system configured to generate electricity from a fuel and an oxidant, the system comprising:
 a first capacitor, comprising:
 a first working electrode, wherein the first working electrode comprises a catalyst for the electrochemical reaction between the fuel and the oxidant and wherein the first working electrode is configured to adsorb the fuel or the oxidant; 
 a first counter electrode; and 
 a first dielectric configured to physically and electrically separate the first working electrode and the first counter electrode; 
   wherein the system is configured to provide a first switchable electrical connection to the first working electrode and the first counter electrode, the first switchable electrical connection being configured to switch between a first electrical load circuit, a first polarization circuit, and no electrical connection.   
     
     
         2 . The system of  claim 1 , wherein the first polarization circuit provides electrical communication between the first working electrode and the first counter electrode without additional applied bias. 
     
     
         3 . The system of  claim 1 , wherein the first polarization circuit comprises a voltage source configured to positively bias the first working electrode and negatively bias the first counter electrode. 
     
     
         4 . The system of  claim 1 , wherein the first working electrode catalyst is selected from the group consisting of Pt, Pd, all noble metals, Ni, Co, Cu, all transition metals, alloys of the preceding, oxides, supported catalysts, and combinations thereof. 
     
     
         5 . The system of  claim 1 , wherein the first counter electrode is selected from the group consisting of Al, Cu, Ni, Zn, steel, stainless steel, Pt, any metal, transparent conductors, conducting polymers, carbon materials, doped silicon, any doped or heavily doped semiconductor, nanowires or nanoparticles of the preceding, and combinations thereof. 
     
     
         6 . The system of  claim 1 , wherein the fuel is a neutral or ionic form of one or more of the following: hydrogen; CO; N 2 ; NO; NO 2 ; sulfur; SO 2 ; syngas; hydrogen sulfide; hydrogen peroxide; lower alkanes; all alkanes, including linear, branched, and cyclic species; all alkenes; all alkynes; all arenes; lower alkane alcohols; partially oxidized, hydroxylated, or sulfonated alkanes, alkenes, alkynes, and arenes; gasoline, kerosene, diesel, JP12, and crude oil; biofuels; ammonia, hydrazine, and methyl amine; boranes; acids; halogens; solvated metal cations; solvated metals and metal containing compounds; particulate metals and metal containing compounds; nanoparticles of any of the preceding; any chemical species that can be electrochemically oxidized; mixtures of any of the preceding; dilutions of the preceding with a solvent or gas; and humidified versions of any of the preceding. 
     
     
         7 . The system of  claim 1 , wherein the oxidant is air or a neutral or ionic form of one or more of the following: oxygen, ozone, hydrogen peroxides, all peroxides, fluorine, chlorine, bromine, iodine, inorganic acids, organic acids, hypochlorite, chlorate, water, solvated metal cations, solvated metals and metal containing compounds, particulate metals and metal containing compounds, nanoparticles of any of the preceding, any chemical species that can be reduced, mixtures of any of the preceding, dilutions of the preceding with a solvent or gas, and humidified versions of any of the preceding. 
     
     
         8 . The system of  claim 1 , further comprising:
 a fuel gas source configured to impinge gaseous fuel on the first working electrode; and   an oxidant gas source configured to impinge gaseous oxidant on the first working electrode.   
     
     
         9 . The system of  claim 8 , wherein the fuel gas source and the oxidant gas source are configured to provide alternating flow of the fuel and the oxidant to the first working electrode. 
     
     
         10 . The system of  claim 8 , wherein the fuel gas source is configured to impinge the fuel on the first working electrode in a first fuel chamber, wherein the oxidant gas source is configured to impinge the oxidant on the first working electrode in a first oxidant chamber, and wherein the system is configured to move the working electrode between the first fuel chamber and the first oxidant chamber. 
     
     
         11 . The system of  claim 10 , wherein the system is configured to move the working electrode between the first fuel chamber and the first oxidant chamber by a mechanism selected from the group consisting of rotational motion and linear motion. 
     
     
         12 . The system of  claim 1 , further comprising a second capacitor, comprising:
 a second working electrode, wherein the second working electrode comprises a catalyst for the electrochemical reaction between the fuel and the oxidant and wherein the second working electrode is configured to adsorb the fuel or the oxidant;   a second counter electrode; and   a second dielectric configured to physically and electrically separate the second working electrode and the second counter electrode;   wherein the system is configured to provide a second switchable electrical connection to the second working electrode and the second counter electrode, the second switchable electrical connection being configured to switch between a second electrical load circuit, a second polarization circuit, and no electrical connection; and   wherein the first capacitor and the second capacitor are electrically connected in series, electrically connected in parallel, or have no shared electrical connection.   
     
     
         13 . The system of  claim 12 , wherein the composition of the first capacitor and the second capacitor are the same composition. 
     
     
         14 . The system of  claim 12 , further comprising a substrate upon which the first capacitor and the second capacitor are disposed. 
     
     
         15 . The system of  claim 12 , wherein the first dielectric and the second dielectric are a unitary dielectric that physically spans between the first capacitor and the second capacitor. 
     
     
         16 . The system of  claim 12 , wherein the first electrical load circuit and the second electrical load circuit provide current to a unified electrical load. 
     
     
         17 . The system of  claim 16 , further comprising a plurality of additional capacitors configured to provide current to the unified electrical load. 
     
     
         18 . The system of  claim 17 , wherein the first capacitor, the second capacitor, and the plurality of additional capacitors are arranged in a packed bed configured to receive the fuel and the oxidant sequentially. 
     
     
         19 . The system of  claim 12 , wherein the first electrical load circuit and the second electrical load circuit provide current to different electrical loads. 
     
     
         20 . A system configured to generate electricity from a fuel and an oxidant, the system comprising:
 a capacitor, comprising:
 a working electrode, wherein the working electrode comprises a catalyst for the electrochemical reaction between the fuel and the oxidant and wherein the working electrode is configured to adsorb the fuel or the oxidant; 
 a counter electrode; and 
 a dielectric that physically and electrically separates the working electrode and the counter electrode; 
   means for exposing the working electrode to the fuel;   means for charging the capacitor by biasing the working electrode such that it becomes positively charged and biasing a counter electrode of the capacitor such that it becomes negatively charged; and   means for the exposing the working electrode to the oxidant;   wherein the system is configured to provide a switchable electrical connection to the working electrode and the counter electrode, the switchable electrical connection being configured to switch between an electrical load circuit, a polarization circuit, and no electrical connection.