Patent ID: 7163759
Filing Date: 2007-01-16
Classification: C25B,H01M,Y02E,Y02P

Abstract:
1. An electrochemical system adapted to operate between a fuel cell mode, an electrolysis mode, and a mode alternating between said electrolysis mode and said fuel cell mode operating on a fuel gas mixture and an oxygen-containing gas mixture, said system comprising: at least one hollow planar cell arranged to form an electrochemical stack, said stack including an electrical contact structure at each end of said stack, said hollow cell defining a central chamber therein and wherein said cell comprises: a hollow planar, substantially impervious, electrolyte within each cell; a hollow planar fuel electrode having an outermost edge and an innermost edge and contacting said electrolyte, said fuel electrode being on one side of the electrolyte; an electronically conductive tapered fuel diffusion layer contacting said fuel electrode and having an innermost edge, an outermost edge, a planar side and a tapered side, wherein said tapered fuel diffusion layer allows fuel and oxidized fuel transport via gaseous diffusion between said tapered fuel diffusion layer and said fuel electrode, said tapered fuel diffusion layer having a configuration being progressively thicker from either said innermost edge to said outermost edge or from said outermost edge to said innermost edge; a fuel chamber for providing a fuel source to said system, said fuel chamber able to communicate with said system; and an air chamber for providing an oxygen source to said system, said air chamber able to communicate with said system, wherein one of said fuel chamber and said air chamber is provided in said central chamber and the other is provided surrounding said system.