Improved Performance of Composite Bipolar Plates for PEMFC Modified by Homogeneously Dispersed Multi-Walled Carbon Nanotube Networks Prepared by In Situ Chemical Deposition

Abstract

Composite bipolar plates with excellent performance play a crucial role in improving the overall performance of proton-exchange-membrane fuel cells. However, for graphite/resin composite bipolar plates, their electrical conductivity and mechanical properties are often too complex to meet the needs of users at the same time. Although nanoconductive fillers can alleviate this problem, the performance improvement for composite bipolar plates is often limited due to problems such as agglomeration. In this study, a uniformly dispersed multi-walled carbon nanotube network was prepared by in situ vapor deposition on the surface and pores of expanded graphite, which effectively avoided the problem of agglomeration and effectively improved the various properties of the composite BPs through the synergistic effect with graphite. With the addition of 2% in situ deposited carbon nanotubes, the modified composite bipolar plate has the best conductivity (334.53 S/cm) and flexural strength (50.24 MPa), and all the properties can meet the DOE requirements in 2025. Using the in situ deposition of carbon nanotubes to modify composite bipolar plates is a feasible route because it can result in multi-walled carbon nanotubes in large quantities and avoid the agglomeration phenomenon caused by adding nanofillers. It can also significantly improve the performance of composite bipolar plates, achieving the high performance of composite bipolar plates at a lower cost.

The fabrication of silicon/dual-network carbon nanofibers/carbon nanotubes as free-standing anodes for lithium-ion batteries

“…Heating treatments were heated to 380 °C at a heating rate of 10 °C min −1 and hydrogen was passed through as the reducing gas for a certain time so that the residual divalent cobalt ions were fully reduced to metallic cobalt particles. 26 The chemical vapor deposition furnace was then heated to 800 °C under Ar atmosphere and chemically deposited in situ for one hour at a certain ratio of Ar to H 2 to C 2 H 2 (30 : 1 : 3). The electrospun fiber films after deposition were washed with dilute nitric acid and deionized water for 0.5 h to remove unreacted metallic cobalt particles.…”

“…Si@CNTs were produced by CVD with the substrate of Si NPs where the same mass fraction of 20% cobalt nitrate was loaded onto the surface of the Si NPs in a certain way. 26 The electrode materials prepared in this work were all used directly as stable anodes without collectors and binders.…”

Progress of bipolar plates for proton exchange membrane fuel cells

“…2022 Li [7] prepared a uniformly dispersed multi-walled carbon nanotube network by in-situ vapour deposition on the surface and pores of expanded graphite, which effectively avoided the agglomeration problem through synergistic interaction with graphite and effectively improved various properties of composite bipolar plates. With the incorporation of 2% in-situ deposited carbon nanotubes, the modified composite bipolar plates have the best conductivity (334.53 S/cm) and flexural strength (50.24 MPa), and all the properties can meet the DOE requirements for 2025.…”

Development of novel composite bipolar plates using surface‐modified conductive carbon filler materials for polymer electrolyte membrane fuel cells

“…16 Of these, bipolar plates (BP) are a significant component with functions like managing water and gas, conducting electricity between nearby cells, creating an impermeable barrier between anode and cathode fuels, removing generated heat and providing structural support to stacks. 17,18 BP constitutes 30% to 50% of the total cost and 60% to 80% of the total weight of a fuel cell stack. 19,20 BP was commonly made of graphite plates with attractive properties like good electrical conductivity and corrosion resistance.…”

“…The main components of PEMFC are the membrane electrode assembly, gas diffusion layer, bipolar plates and end plates 16 . Of these, bipolar plates (BP) are a significant component with functions like managing water and gas, conducting electricity between nearby cells, creating an impermeable barrier between anode and cathode fuels, removing generated heat and providing structural support to stacks 17,18 . BP constitutes 30% to 50% of the total cost and 60% to 80% of the total weight of a fuel cell stack 19,20 .…”