NOVELTY - A passive fuel cell system (100) comprises cell unit (102) comprising cathode current collector (110), anode current collector (112) and membrane electrode assembly (114); anode fuel supplying unit (104); cathode fuel supplying unit (126); and heat-conductive material layer (108), disposed between cathode current collector and cathode fuel supplying unit and/or between anode current collector and anode fuel supplying unit. The layer comprises first portion located in cell system reaction area and second portion extending to outside of reaction area in a direction parallel to cell unit.    USE - As a passive fuel cell system (claimed), useful in portable electronic products selected from mobile phones, laptop computers, and digital cameras.    ADVANTAGE - The heat-conductive material layer disposed on a side of the cathode current collector and/or the anode current collector, extends to the outside of the cell system reaction area, and thus the heat-conductive material layer transfers the high temperature inside the cell to a relative low temperature end, and effectively dissipates the waste heat generated in the working of the cell, and maintains the working temperature of the cell in a stable range. The heat-conductive material layer also does not influence the temperature of the membrane electrode assembly and the output power, and does not influence the water recycling efficiency of the cathode end.    DETAILED DESCRIPTION - A passive fuel cell system (100) comprises at least one cell unit (102) comprising a cathode current collector (110); an anode current collector (112); and a membrane electrode assembly (114), disposed between the cathode current collector and the anode current collector; an anode fuel supplying unit (104), disposed on a side of the anode current collector; a cathode fuel supplying unit (126), disposed on a side of the cathode current collector; and a heat-conductive material layer (108), disposed between the cathode current collector and the cathode fuel supplying unit and/or between the anode current collector and the anode fuel supplying unit. The cell system reaction area is defined by the cell unit, anode fuel supplying unit, and cathode fuel supplying unit. The heat-conductive material layer comprises a first portion located in the cell system reaction area and a second portion extending to the outside of the cell system reaction area in a direction parallel to the cell unit, where the first portion of the heat-conductive material layer has at least one opening.    DESCRIPTION OF DRAWING(S) - The figure shows schematic view of a passive fuel cell system.    Passive fuel cell system (100)    Cell unit (102)    Anode fuel supplying unit (104)    Heat-conductive material layer (108)    Cathode current collector (110)    Anode current collector (112)    Membrane electrode assembly (114)    Cathode fuel supplying unit (126)