碳纤维长度对三层梯度孔碳纸性能的影响研究

Study on Effect of Carbon Fiber Length on Properties of Three-layer Gradient Porous Carbon Paper

关键词:  三层碳纸  碳纤维长度  气体扩散层  梯度孔

Key Words:three-layer carbon paper  carbon fiber length  gas diffusion layer  gradient porous

摘要:为研究不同长度的碳纤维配抄制备的梯度孔碳纸性能，本研究选取3种长度（2、4和8 mm）的碳纤维原料，探讨不同分散剂类型和纤维长度配比对单层碳纸和三层梯度孔碳纸的匀度、电阻率、抗张强度、孔隙率和透气度的影响。结果表明，卡波姆（Carbomer）作为分散剂得到的碳纤维分散效果最佳，分散稳定性指数为4.04。匀度指数在10~13之间的单层碳纸性能较好，其电阻率为90 mΩ·cm，抗张强度为0.250 kN/m，孔隙率为92%，透气度为1 200 L/(m²·s)。与单层碳纸相比，三层梯度孔碳纸的抗张强度（0.410 kN/m）和透气度（1 230 L/(m²·s)）有所增加，且碳纤维长度配比对三层梯度孔碳纸的孔隙形貌影响显著；长度4和8 mm的碳纤维配抄制备的三层梯度孔碳纸的性能优于其他2组（2和4 mm配抄及2和8 mm配抄），其电阻率低至19.53 mΩ·cm，孔隙率为92%。

Abstract:In order to study the properties of graded porous carbon paper prepared with carbon fibers of different lengths， carbon fibers of 2， 4 and 8 mm were selected as raw materials， and the effects of different dispersant types and fiber length ratios on the uniformity， resistivity， tensile strength， porosity， and air permeability of single- and three-layer graded porous carbon paper were investigated. The results showed that the carbon fiber obtained by Carbomer as dispersant had the best dispersion effect with the dispersion stability index of 4.04. The carbon paper with the evenness index between 10~13 had good resistivity of 90 mΩ·cm， tensile strength of 0.250 kN/m， porosity of 92%， and air permeability of 1 200 L/（m²·s）. Compared with single-layer carbon paper， the tensile strength （0.410 kN/m） and air permeability （1 230 L/（m²·s） of three-layer gradient porous carbon paper both increased， and the carbon fiber length ratio had an important effect on the pore morphology of three-layer gradient porous carbon paper. The 4 and 8 mm carbon fiber combination was superior to the other two sets （2 and 4 mm combination， 2 and 8 mm combination） of three-layer gradient porous carbon paper， with a resistivity as low as 19.53 mΩ·cm and porosity of 92%.