To sufficiently improve the electrical conductivity of composite bipolar plates is crucial for their application in fuel cells and redox flow batteries. Eliminating the resin-rich layer on the surface of composite bipolar plates turns to be an effective approach. In this work, graphite/resin composite bipolar plates with advanced performance and durability are obtained after surface treatment with cactus-like carbon nanofibers which grow from the catalyst cores and stretch out to form cactus-like structures. Morphology and structure of the carbon nanofibers, as well as the morphology, electrical conductivity, electrochemical properties and charge-discharge performance of the bipolar plates in a vanadium redox flow battery (VRFB) are investigated. Results show that surface treatment with graphitized cactus-like carbon nanofibers significantly enhance the conductivity of the composite plates which reaches as high as 198.7 S cm⁻¹, and the area specific resistance can be reduced to 25.4 mΩ cm². The VRFB single cell with the modified bipolar plate exhibits very high energy efficiency of 86.28%, at 100 mA cm⁻², and shows excellent durability in charge-discharge cycling test. With the superior properties above, composite bipolar plates after surface treatment with cactus-like carbon nanofibers are promising candidates for VRFBs.

为了充分提高复合双极板的电导率，对于其在燃料电池和氧化还原液流电池中的应用至关重要。消除复合双极板表面上的富树脂层是一种有效的方法。在这项工作中，经过用仙人掌状碳纳米纤维表面处理后得到的石墨/树脂复合双极板具有先进的性能和耐用性，该碳纳米纤维从催化剂芯中生长出来并延伸形成仙人掌状结构。研究了碳纳米纤维的形态和结构，以及钒还原液流电池（VRFB）中双极板的形貌，电导率，电化学性能和充放电性能。^-1，并且可以将面积比电阻减小到25.4mΩcm ²。具有修饰的双极板的VRFB单电池在100mA cm ^-2时显示出非常高的能量效率，为86.28％，并且在充放电循环测试中显示出优异的耐久性。凭借上述优越的性能，经过类似仙人掌的碳纳米纤维表面处理的复合双极板有望成为VRFB的候选材料。