Electrochemical energy cell system

Abstract

A metal halogen electrochemical energy cell system that generates an electrical potential. One embodiment of the system includes at least one cell including at least one positive electrode and at least one negative electrode, at least one electrolyte, a mixing venturi that mixes the electrolyte with a halogen reactant, and a circulation pump that conveys the electrolyte mixed with the halogen reactant through the positive electrode and across the metal electrode. Preferably, the negative electrodes are made of zinc, the metal is zinc, the positive electrodes are made of porous carbonaceous material, the halogen is chlorine, the electrolyte is an aqueous zinc-chloride electrolyte, and the halogen reactant is a chlorine reactant. Also, variations of the system and a method of operation for the systems.

1 . A metal halogen electrochemical energy system whereby an electrical potential is generated, comprising at least one cell that includes:
 at least one positive electrode;   at least one negative electrode;   a reaction zone between the positive electrode and the negative electrode;   at least one electrolyte that includes a metal and a halogen; and   a circulation pump that conveys the electrolyte through the reaction zone, wherein the electrolyte and a halogen reactant are mixed before, at, or after the pump.   
     
     
         2 . A system as in  claim 1 , wherein the positive electrode comprises porous carbonaceous material. 
     
     
         3 . A system as in  claim 1 , wherein the negative electrode comprises zinc, the metal comprises zinc, the halogen comprises chlorine, the electrolyte comprises an aqueous zinc-chloride electrolyte, and the halogen reactant comprises a chlorine reactant. 
     
     
         4 . A system as in  claim 1 , further comprising a mixing venture that mixes the electrolyte and the halogen reactant. 
     
     
         5 . A system as in  claim 1 , wherein before being conveyed through the reaction zone, a flow of the electrolyte undergoes concurrent first, second, and third order binary splits to provide a same flow resistance for different paths to the reaction zone. 
     
     
         6 . A system as in  claim 1 , further comprising a reservoir from which the electrolyte is conveyed by the circulation pump to the cell and to which the electrolyte returns from the cell. 
     
     
         7 . A system as in  claim 6 , further comprising an upward-flowing electrolyte return manifold to facilitate purging of gas from the cell. 
     
     
         8 . A system as in  claim 6 , further comprising a return pipe through which the electrolyte returns from the cell to the reservoir. 
     
     
         9 . A system as in  claim 6 , wherein the halogen reactant is supplied from an external source. 
     
     
         10 . A system as in  claim 6 , wherein the halogen reactant is supplied under pressure, and wherein an enthalpy of expansion of the halogen from the external source acts to cool the system. 
     
     
         11 . A system as in  claim 1 , further comprising a metering valve or positive displacement pump that controls flow of the halogen reactant. 
     
     
         12 . A system as in  claim 1 , further comprising plural such cells. 
     
     
         13 . A system as in  claim 12 , wherein plural horizontal such cells are stacked vertically in the system. 
     
     
         14 . A system as in  claim 12 , wherein the plural cells further comprise plural cell frames. 
     
     
         15 . A system as in  claim 14 , wherein the cell frames are circular to facilitate insertion of the plural cells into a pressure containment vessel. 
     
     
         16 . A system as in  claim 14 , further comprising the pressure containment vessel. 
     
     
         17 . A system as in  claim 14 , wherein each of the cell frames further comprises a feed manifold element, distribution channels, flow splitting nodes, spacer ledges, flow merging nodes, collection channels, and a return manifold element. 
     
     
         18 . A system as in  claim 17 , wherein
 the feed manifold element in each of the plural cells frames aligns with the feed manifold element in another of the cell frames, thereby forming a feed manifold;   the distribution channels and the flow splitting nodes in each of the cell frames align with the distribution channels and the flow splitting nodes in another of the cell frames, thereby forming a distribution zone;   the positive electrode for each cell sits above or below the negative electrode for each cell on the spaces ledges of the cell frames, thereby forming alternating layers of positive electrodes and negative electrodes;   the flow merging nodes and the collection channels in each of the plural cells frames align with the flow merging nodes and the collection channels in another of the cell frames, thereby forming a collection zone; and   the return manifold element in each of the cell frames aligns with the return manifold element in another of the cell frames, thereby forming a return manifold.   
     
     
         19 . A system as in  claim 17 , wherein each of the cell frames further comprise bypass conduit elements for fluid flow and electrical wires or cables. 
     
     
         20 . A system as in  claim 17 , wherein each of the cell frames further provides a pass-through for an alignment and clamping element to align and to hold the cell frames together, and further comprises the alignment and clamping element. 
     
     
         21 . A system as in  claim 12 , wherein vertical steps in cell geometry result in interrupted electrolyte flow paths within each of the plural cells, thereby interrupting shunt currents that otherwise would continue to occur after electrolyte flow stops. 
     
     
         22 . A system as in  claim 12 , further comprising:
 a feed manifold and a distribution zone for the electrolyte to the plural cells;   a collection zone and a return manifold for the electrolyte from the plural cells.   
     
     
         23 . A system as in  claim 22 , wherein the positive electrode and the negative electrode in each cell are arranged to maintain contact with a pool of electrolyte in each cell when electrolyte flow stops and the feed manifold, distribution zone, collection zone, and return manifold drain. 
     
     
         24 . A system as in  claim 22 , further comprising a reservoir from which the electrolyte is conveyed by the circulation pump to the feed manifold and to which the electrolyte returns from the return manifold. 
     
     
         25 . A system as in  claim 24 , further comprising an upward-flowing electrolyte return manifold to facilitate purging of gas from the cell. 
     
     
         26 . A system as in  claim 24 , further comprising a return pipe that is internal to the cell frames through which the electrolyte returns from the cell to the reservoir. 
     
     
         27 . A metal halogen electrochemical energy cell system, comprising
 at least one cell that includes a positive electrode, a negative electrode, a reaction zone between the positive electrode and the negative electrode, and flow distribution zones;   an aqueous electrolyte that includes the metal and the halogen;   a reservoir where the electrolyte is collected; and   a circulation pump that conveys the electrolyte through the system;   wherein the flow distribution zones contain flow-splitting nodes in which flow channels are concurrently and repeatedly divided in two to provide a same flow resistance for different paths to the reaction zone.   
     
     
         28 . A system as in  claim 27 , wherein the negative electrode comprises zinc, the halogen comprises chlorine, the positive electrode comprises porous carbonaceous material, the electrolyte comprises an aqueous zinc-chloride electrolyte, and the halogen reactant comprises a chlorine reactant. 
     
     
         29 . A metal halogen electrochemical energy cell system, comprising
 at least one cell that includes a positive electrode, a negative electrode, and a reaction zone between the positive electrode and the negative electrode;   an aqueous electrolyte that includes the metal and the halogen;   a reservoir where the electrolyte is collected;   a circulation pump that conveys the electrolyte through the system; and   a halogen metering element by which the halogen is replenished from an external source.   
     
     
         30 . A system as in  claim 29 , wherein the negative electrode comprises zinc, the metal comprises zinc, the halogen comprises chlorine, the positive electrode comprises carbonaceous material, the electrolyte comprises an aqueous zinc-chloride electrolyte, and the halogen reactant comprises a chlorine reactant. 
     
     
         31 . A system as in  claim 29 , wherein the halogen metering element is a valve or a positive displacement pump. 
     
     
         32 . A system as in  claim 29 , wherein chlorine is fed to the halogen metering element from the external source. 
     
     
         33 . A system as in  claim 29 , wherein an enthalpy of expansion of the halogen from the external source cools the system. 
     
     
         34 . A metal halogen electrochemical energy cell system, comprising
 at least one cell that includes a positive electrode, a negative electrode, and a reaction zone between the positive electrode and the negative electrode;   an aqueous electrolyte that includes a metal and a halogen;   a reservoir where the electrolyte is collected; and   a circulation pump that conveys the electrolyte through the system;   wherein a balancing voltage is applied to inhibit electrochemical reactions and thereby maintain system availability when the system is in a standby or stasis mode.   
     
     
         35 . A system as in  claim 34 , wherein the negative electrode comprises zinc, the halogen comprises chlorine, the positive electrode comprises carbonaceous material, the electrolyte comprises an aqueous zinc-chloride electrolyte, and the halogen reactant comprises a chlorine reactant. 
     
     
         36 . A metal halogen electrochemical energy cell system, comprising
 at least one cell that includes a positive electrode, a negative electrode, and a reaction zone between the positive electrode and the negative electrode;   an aqueous electrolyte that includes the metal and the halogen;   a halogen reactant that is mixed with the electrolyte;   a reservoir where the electrolyte is collected;   a circulation pump that conveys the electrolyte through the system;   output terminals connected to at least the cell; and   a blocking diode that is applied to the output terminals to inhibit reverse current flow within the system.   
     
     
         37 . A system as in  claim 36 , wherein the negative electrode comprises zinc, the metal comprises zinc, the halogen comprises chlorine, the positive electrode comprises carbonaceous material, the electrolyte comprises an aqueous zinc-chloride electrolyte, and the halogen reactant comprises a chlorine reactant. 
     
     
         38 . A method of generating an electrical potential using a metal halogen electrochemical energy system, comprising the steps of:
 mixing an electrolyte with a halogen reactant, with the electrolyte including a metal and a halogen; and   conveying the electrolyte through at least one cell that includes at least one positive electrode and at least one negative electrode, wherein the electrolyte passes through the positive electrode and across the negative electrode.   
     
     
         39 . A method as in  claim 38 , wherein the positive electrode comprises porous carbonaceous material. 
     
     
         40 . A method as in  claim 38 , wherein the negative electrode comprises zinc, the metal comprises zinc, the halogen comprises chlorine, the electrolyte comprises an aqueous zinc-chloride electrolyte, and the halogen reactant comprises a chlorine reactant. 
     
     
         41 . A method as in  claim 38 , wherein the electrolyte and the halogen reactant are mixed by a mixing venturi. 
     
     
         42 . A method as in  claim 38 , further comprising the step of subjecting a flow of the electrolyte to concurrent first, second, and third order splits before being conveyed through the positive electrode, thereby providing a same flow resistance for different paths to a reaction zone between the positive electrode and the negative electrode. 
     
     
         43 . A method as in  claim 38 , wherein the electrolyte is circulated from a reservoir to the cell and returns from the cell to the reservoir. 
     
     
         44 . A method as in  claim 43 , further comprising the step of upward-flowing the electrolyte in a return manifold to facilitate purging gas from the cell. 
     
     
         45 . A method as in  claim 43 , further comprising the step of returning the electrolyte to the reservoir through a pipe. 
     
     
         46 . A method as in  claim 43 , further comprising the step of supplying the halogen reactant to the system from an external source. 
     
     
         47 . A method as in  claim 43 , wherein an enthalpy of expansion of the halogen from the external source acts to cool the system. 
     
     
         48 . A method as in  claim 38 , further comprising the step of controlling flow of the halogen reactant using a metering valve or positive displacement pump. 
     
     
         49 . A method as in  claim 38 , wherein conveying the electrolyte through at least one cell further comprises conveying the electrolyte through plural such cells. 
     
     
         50 . A method as in  claim 49 , wherein the plural horizontal cells are stacked vertically in the system. 
     
     
         51 . A method as in  claim 49 , wherein the plural cells further comprise plural cell frames. 
     
     
         52 . A method as in  claim 51 , wherein the cell frames are circular to facilitate insertion of the plural cells into a pressure containment vessel. 
     
     
         53 . A method as in  claim 51 , wherein the plural cells are contained in a pressure containment vessel. 
     
     
         54 . A method as in  claim 51 , wherein conveying the electrolyte through the plural cell frames further comprises conveying the electrolyte through a feed manifold element, distribution channels, flow splitting nodes, spacer ledges, flow merging nodes, collection channels, and a return manifold element. 
     
     
         55 . A method as in  claim 54 , wherein
 the feed manifold element in each of the plural cells frames aligns with the feed manifold element in another of the cell frames, thereby forming a feed manifold;   the distribution channels and the flow splitting nodes in each of the cell frames align with the distribution channels and the flow splitting nodes in another of the cell frames, thereby forming a distribution zone;   the positive electrode for each cell sits above or below the negative electrode for each cell on the spaces ledges of the cell frames, thereby forming alternating layers of positive electrodes and negative electrodes;   the flow merging nodes and the collection channels in each of the plural cells frames align with the flow merging nodes and the collection channels in another of the cell frames, thereby forming a collection zone; and   the return manifold element in each of the cell frames aligns with the return manifold element in another of the cell frames, thereby forming a return manifold.   
     
     
         56 . A method as in  claim 54 , wherein each of the cell frames further comprise bypass conduit elements for fluid flow and electrical wires or cables. 
     
     
         57 . A method as in  claim 54 , wherein each of the cell frames further provides a pass-through for an alignment and clamping element to align and to hold the cell frames together, and further comprises the alignment and clamping element. 
     
     
         58 . A method as in  claim 49 , further comprising the step of using vertical steps in cell geometry to interrupt flow paths of the electrolyte within each of the plural cells to interrupt shunt currents that otherwise would continue to occur after electrolyte flow stops. 
     
     
         59 . A method as in  claim 49 , wherein conveying the electrolyte through the plural cells further comprises conveying the electrolyte through a feed manifold and a distribution zone to the plural cells and through a collection zone and a return manifold from the plural cells. 
     
     
         60 . A method as in  claim 59 , further comprising the step of maintaining contact with a pool of electrolyte in each cell when electrolyte flow stops and the feed manifold, distribution zone, collection zone, and return manifold drain. 
     
     
         61 . A method as in  claim 59 , wherein conveying the electrolyte through the plural cells further comprises conveying the electrolyte from a reservoir to the feed manifold and from the return manifold to the reservoir. 
     
     
         62 . A method as in  claim 61 , further comprising the step of upward-flowing electrolyte in the return manifold to facilitate purging gas from the cell. 
     
     
         63 . A method as in  claim 61 , further comprising the step of returning the electrolyte to the reservoir through a pipe that is internal to the cell frames. 
     
     
         64 . A method of generating an electrical potential using a metal halogen electrochemical energy system, comprising the steps of:
 conveying an aqueous electrolyte that includes the metal and the halogen through at least one cell that includes a positive electrode, a negative electrode, a reaction zone between the positive electrode and the negative electrode, and flow distribution zones; and   collecting the electrolyte in a reservoir;   wherein the flow distribution zones contain flow-splitting nodes in which flow channels are concurrently and repeatedly divided in two to provide a same flow resistance for different paths to the reaction zone.   
     
     
         65 . A method as in  claim 64 , wherein the negative electrode comprises zinc, the metal comprises zinc, the halogen comprises chlorine, the positive electrode comprises carbonaceous material, the electrolyte comprises an aqueous zinc-chloride electrolyte, and the halogen reactant comprises a chlorine reactant. 
     
     
         66 . A method of generating an electrical potential using a metal halogen electrochemical energy system, comprising the steps of:
 conveying an aqueous electrolyte that includes the metal and the halogen through at least one cell that includes a positive electrode, a negative electrode, and a reaction zone between the positive electrode and the negative electrode;   collecting the electrolyte in a reservoir; and   replenishing the halogen from an external source using a halogen metering element.   
     
     
         67 . A method as in  claim 66 , wherein the negative electrode comprises zinc, the metal comprises zinc, the halogen comprises chlorine, the positive electrode comprises carbonaceous material, the electrolyte comprises an aqueous zinc-chloride electrolyte, and the halogen reactant comprises a chlorine reactant. 
     
     
         68 . A method as in  claim 66 , wherein the halogen metering element is a valve or positive displacement pump. 
     
     
         69 . A method as in  claim 66 , wherein chlorine is fed to the halogen metering element from the external source. 
     
     
         70 . A method as in  claim 66 , wherein an enthalpy of expansion of the halogen from the external source acts to cools the system. 
     
     
         71 . A method of generating an electrical potential using a metal halogen electrochemical energy system, comprising the steps of:
 conveying an aqueous electrolyte that includes a metal and a halogen through at least one cell that includes a positive electrode, a negative electrode, and a reaction zone between the positive electrode and the negative electrode;   collecting the electrolyte in a reservoir; and   applying a balancing voltage to inhibit electrochemical reactions and thereby maintain system availability when the system is in a standby or stasis mode.   
     
     
         72 . A method as in  claim 71 , wherein the negative electrode comprises zinc, the metal comprises zinc, the halogen comprises chlorine, the positive electrode comprises carbonaceous material, the electrolyte comprises an aqueous zinc-chloride electrolyte, and the halogen reactant comprises a chlorine reactant. 
     
     
         73 . A method of generating an electrical potential using a metal halogen electrochemical energy cell system, comprising the steps of:
 conveying an aqueous electrolyte that includes a metal and a halogen through at least one cell that includes a positive electrode, a negative electrode, and a reaction zone between the positive electrode and the negative electrode;   mixing a halogen reactant with the electrolyte;   collecting the electrolyte in a reservoir; and   applying a blocking diode to output terminals of the system to inhibit reverse current flow within the system.   
     
     
         74 . A method as in  claim 73 , wherein the negative electrode comprises zinc, the metal comprises zinc, the halogen comprises chlorine, the positive electrode comprises carbonaceous material, the electrolyte comprises an aqueous zinc-chloride electrolyte, and the halogen reactant comprises a chlorine reactant.