Patent ID: 9029039
Filing Date: 2015-05-12
Classification: C25B,H01M,Y02E

Abstract:
1. A cell stack, comprising a plurality of fuel cells or electrolysis cells arranged in layers on top of each other, each of said cells comprising an anode an electrolyte and a cathode, each layer of cells is divided by a plurality of interconnects, one between each cell, the interconnects are provided with gas channels on each side facing the anode or cathode side of the adjacent cell, the gas channels run from an inlet portion to an outlet portion of said cells, the substantial direction from the anode inlet portion to the anode outlet portion of the anode side of each cell defines the anode gas flow direction of each cell and the substantial direction from the cathode inlet portion to the cathode outlet portion of the cathode side of each cell defines the cathode gas flow direction of each cell, each cell in the stack has one of: internal co-flow of the anode gas flow direction relative to the cathode gas flow direction or, internal cross-flow of the anode gas flow direction relative to the cathode gas flow direction or, internal counter-flow of the anode gas flow direction relative to the cathode gas flow direction the interfacing sides of adjacent cells on each side of an interconnect are oriented in either of: interconnect co-flow interconnect cross-flow interconnect counter-flow, wherein the stacked cells are arranged such that each individual cell and adjacent cells have a combination of said internal co-flow, internal cross-flow or internal counter-flow of the anode gas direction relative to the cathode gas flow direction internally in each individual cell and have a combination of said interconnect co-flow, interconnect cross-flow or interconnect counter-flow between two interfacing sides of adjacent cells, said stack comprising at least one set of primary cells and adjacent secondary cells, wherein the anode outlet gas of at least one primary cell is directed to the anode inlet portion of at least one secondary cell, whereby the primary anode outlet gas performs a second flow pass through said secondary cell, wherein the anode outlet gas of all primary cells is collected, mixed and redistributed to the anode inlet gas portion of all secondary cells, or the cathode outlet gas of all primary cells is collected, mixed and redistributed to the cathode inlet gas portion of all secondary cells, or both the anode outlet gas of all primary cells is collected, mixed and redistributed to the anode inlet gas portions of all secondary cells and the cathode outlet gas of all primary cells is collected, mixed and redistributed to the cathode inlet gas portion of all secondary cells, whereby the primary anode outlet gas or the primary cathode outlet gas or both the primary anode outlet gas and the primary cathode outlet gas perform a second cell flow pass, and whereby the at least one primary cell has anode gas flow in a first direction and cathode gas flow in a second substantially opposite direction relative to the anode gas flow direction such that said primary cell internally has counter-flow and said at least one secondary cell has anode gas flow in said second direction and cathode gas flow in said second direction such that said at least one secondary cell internally has Co-flow (“H”).