Bipolar plate for fuel cell and fuel cell

Abstract

A bipolar plate for a fuel cell is provided. The bipolar plate for the fuel cell has a plurality of flow channels, and a rib is defined between neighboring two flow channels. A side surface of the rib is non-porous. A top surface of the rib may be a roughened surface in order to improve performance of the fuel cell.

What is claimed is: 
     
         1 . A bipolar plate for a fuel cell, the bipolar plate comprising a plurality of flow channels, wherein a rib is defined between neighboring two of the flow channels, and the bipolar plate is characterized in that: a top surface of the rib is a roughened surface and a side surface of the rib is non-porous. 
     
     
         2 . The bipolar plate for the fuel cell according to  claim 1 , wherein the roughened surface of the rib has a pore diameter of approximately 20 μm to 200 μm. 
     
     
         3 . The bipolar plate for the fuel cell according to  claim 1 , wherein the roughened surface of the rib has a pore area fraction of approximately 50% to 90%. 
     
     
         4 . The bipolar plate for the fuel cell according to  claim 1 , wherein the roughened surface of the rib has a roughness of approximately 0.1 μm to 10 μm. 
     
     
         5 . The bipolar plate for the fuel cell according to  claim 1 , wherein a material of the bipolar plate comprises metal, graphite, or a composite material. 
     
     
         6 . A bipolar plate for a fuel cell, the bipolar plate comprising a plurality of flow channels, wherein a rib is defined between neighboring two of the flow channels, and the bipolar plate is characterized in that: a top surface of the rib is a roughened surface, wherein the roughened surface of the rib is made through surface polishing and ultrasonic cavitation techniques or an electrical discharge processing technique. 
     
     
         7 . The bipolar plate for the fuel cell according to  claim 6 , wherein the roughened surface of the rib has a pore diameter of approximately 20 μm to 200 μm. 
     
     
         8 . The bipolar plate for the fuel cell according to  claim 6 , wherein the roughened surface of the rib has a pore area fraction of approximately 50% to 90%. 
     
     
         9 . The bipolar plate for the fuel cell according to  claim 6 , wherein the roughened surface of the rib has a roughness of approximately 0.1 μm to 10 μm. 
     
     
         10 . The bipolar plate for the fuel cell according to  claim 6 , wherein a material of the bipolar plate comprises metal, graphite, or a composite material. 
     
     
         11 . A fuel cell, comprising:
 a plurality of bipolar plates, wherein each of the bipolar plates has a plurality of flow channels, and a rib is defined between neighboring two of the flow channels; and   at least one membrane electrode assembly (MEA), disposed among the bipolar plates, wherein   a top surface of the rib is a roughened surface and a side surface of the rib is non-porous.   
     
     
         12 . The fuel cell according to  claim 11 , wherein the roughened surface of the rib has a pore diameter of approximately 20 μm to 200 μm. 
     
     
         13 . The fuel cell according to  claim 11 , wherein the roughened surface of the rib has a pore area fraction of approximately 50% to 90%. 
     
     
         14 . The fuel cell according to  claim 11 , wherein the roughened surface of the rib has a roughness of approximately 0.1 μm to 10 μm. 
     
     
         15 . The fuel cell according to  claim 11 , wherein a material of the bipolar plate comprises metal, graphite, or a composite material.