超声分散技术在燃料电池复合材料双极板制备中的应用

Application of ultrasonic dispersion in the preparation of composite bipolar plates for PEMFC

以天然鳞片石墨、炭黑和环氧改性酚醛树脂为原料,采用模压工艺制备石墨/聚合物复合材料双极板。研究了不同原料混合方式对复合材料双极板结构与性能的影响,并分别以最优化条件下制备的复合材料双极板和无孔石墨双极板组装了PEMFC单电池,对复合材料双极板的电化学性能进行了初步对比研究。结果表明:采用超声分散方式制得的双极板的各项性能都明显优于传统的机械混合方式制得的复合材料双极板;在低电流密度条件下,以复合材料双极板组装的PEMFC和以无孔石墨板组装的PEMFC的电池电压及功率密度基本一致;而由于复合双极板的电导率低于无孔石墨双极板,因此在大电流密度下,以复合材料双极板组装的PEMFC的电池电压和功率密度皆小于以无孔石墨板为双极板的PEMFC。

Natural graphite,carbon black,and epoxy modified phenolic resin were chosen to make graphite/polymer composite bipolar plates by compression molding.The influences of preparing methods on the structure and properties of the composite bipolar plates were investigated,and single cells were assembled with the composite bipolar plate and non-porous graphite plate respectively to investigate the electrochemical property of the composite bipolar plates.The results showed that properties of the composite bipolar plates prepared by ultrasonic dispersion were obviously better than that prepared with a kneader.The battery voltage and power density of the proton exchange membrane fuel cells（PEMFCs） assembled with composite bipolar plate and non-porous graphite plate respectively are similar at low current density.While at high current density,both battery voltage and power density of the PEMFC assemble with composite bipolar plate are lower than that assembled with non-porous graphite bipolar plate,which is the result of the relatively lower electric conductivity of the composite bipolar plate.