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This study concerns the use of conductive carbon material with different content and structure to produce carbon fiber paper for use in proton exchange membrane fuel cells, and investigates how changes in the content and structure of the conductive carbon material influence fuel cell performance. In this study, phenolic resin is used as a conductive carbon material, and is subjected to heat treatment at temperatures of 700 °C, 1000 °C, and 1400 °C, which changes its structure. Before carbon fiber paper is prepared from carbon felt, the felt is treated with phenolic resin solutions with resin content of 5, 10, 15, 20, 25, and 30 wt%. During fuel cell testing, torsion of 40, 60, 80, 100, and 120 kgf-cm is applied. The study found that when the phenolic resin content is 15 wt%, the heat treatment temperature 1400 °C, the test area 25 cm 2 , and the test temperature 65 °C, a fuel cell can achieve a current density of 2020 mA cm −2 at 0.5 V and torque of 120 kgf-cm.

The negative electrode of a lithium-ion battery should have the characteristics of large charge capacity, excellent charge and discharge cycle, steady discharge voltage, low irreversible charge capacity, and stable electrolyte. Natural graphite and mesocarbon microbeads (MCMB) are the most common materials used for the negative electrodes of such batteries. This study examines the effect of the use of homemade non-modified MCMB (HMM), modified MCMB (HMMQ), and natural graphite (NG) to produce electrodes on the batteries' high current charge–discharge behavior. In this experiment, the charge–discharge results showed that the voltage plateaus of HMM and HMMQ sloped due to short-range structural order, which enabled the intercalation and deintercalation of lithium ions to occur at different voltages. When HMMQ was charging and discharging high current at a rate of 2 C, the battery's charge capacity reached 160 mAh·g − 1 and the coulometric efficiency exceeded 96%. Following the start of charging and discharging, a stable solid electrolyte interface (SEI) layer formed on HMMQ. The charge capacity of HMMQ was approximately 167 mAh·g − 1 after 100 charge–discharge cycles at 1 C, and the cycles were stable. According to FTIR analysis, the content of the SEI layer produced within HMMQ consisted of Li 2 CO 3 and (CH 2 OCOLi) 2 , and was stable, non-soluble, and passive. Negative electrodes made using modified material displayed good stability throughout many cycles when charging and discharging at a high current.

This study discusses the relationship between performance and carbon fiber diameter (400 nm–1 μm) in fuel cells employing carbon fiber paper produced from PAN fiber felt, and also examines the effect of carbon fiber paper thickness, air permeability, porosity, and surface resistivity on performance. The researchers fabricate gas diffusion layers (GDLs) with a small carbon fiber diameter from PAN fiber employing the two processes of stabilization and carbonization, and investigate the relationship between fiber diameter and air permeability in the gas diffusion layer material. Carbon fiber paper made in this study is left as is or impregnated with 10 wt% phenolic resin or FEP. When the tested area is 25 cm2, the test temperature 40 °C, and the carbon fiber paper impregnated with 10 wt% phenolic resin, the paper has a fiber diameter of 1 μm and an air permeability is 29 cm3 cm−2 s−1, and a test fuel cell yields 997 mA cm−2 at a load of 0.5 V. Carbon fiber paper impregnated with 10 wt% FEP has a smaller carbon fiber diameter of 400 nm and an air permeability of only 1 cm3 cm−2 s−1; a test fuel cell made with this material yields 683 mA cm−2 at a load of 0.5 V.

This study uses fuel cell gas diffusion layers (GDLs) fabricated in the laboratory from carbon fiber cloth with different concentrations of hydrophobic agents in proton exchange membrane fuel cells (PEMFCs), and investigates the relationship between the hydrophobic agent content of the carbon fiber cloth and fuel cell performance. The paper examines the effect of hydrophobic agent content on GDL thickness, contact angle, air permeability, and surface and through-plane resistivity. Carbon fiber cloth is impregnated with hydrophobic agent concentrations of 0, 3, 5, 10, 30, and 50 wt%, and the resulting GDLs are subjected to performance tests. When the test piece area is 25 cm 2 , the test temperature 80 °C, the gasket thickness 0.36 mm, and the hydrophobic agent content 5 wt%, a fuel cell using the GDL has a current density of 1430 mA cm −2 at 0.3 V.

This study uses fuel cell gas diffusion layers (GDLs) fabricated in the laboratory from carbon fiber cloth with different structure in proton exchange membrane fuel cells (PEMFCs), and investigates the relationship between the structure of the carbon fiber cloth and fuel cell performance.The paper discusses the relationship between fuel cell performance and structure of the carbon fiber cloth, and also examines the effect of the carbon fiber cloth’s thickness, air permeability, surface resistivity, XRD and elemental analysis. Carbon fiber cloth is carbonized at rates of 190, 220, 250, 280, and 310 °C min −1 respectively, and the resulting carbon fiber cloth is tested in cells. When the test piece area is 25 cm 2 , the test temperature 40 °C, the gasket thickness 0.36 mm, and the carbonization rate 280 °C min −1 , a fuel cell using the carbon fiber cloth achieves a current density of 1968 mA cm −2 and a maximum power density of 633 mW cm −2 at 0.3 V.

This study employed fuel cell gas diffusion layers (GDLs) consisting of carbon fiber paper made from carbon fiber felt with different yard weights in proton exchange membrane fuel cells (PEMFCs), and investigated the relationship between the yard weight of the carbon fiber paper and the fuel cell performance and thickness of the gasket. In this paper we discuss the relationship between carbon fiber felt with different yard weights and fuel cell performance and also explore the effect of carbon fiber paper thickness, air permeability, surface resistivity, and structural study. We focused on the material used for the gas diffusion layer in this study. Carbon fiber paper made in-house in this study contained 10 wt% (all percentages are by weight unless otherwise noted) phenolic resin. When the tested area was 25 cm 2 , the test temperature was 40 °C, the gasket thickness was 0.06 mm, and the yard weight 70 g m −2 , fuel cell current density was 1968 mA cm −2 at a load 0.3 V. When the gasket thickness was 0.36 mm and yard weight was 190 g m −2 , fuel current density was 1710 mA cm −2 at a load of 0.3 V.

This study uses fuel cell gas diffusion layers (GDLs) made from carbon fiber paper containing carbon black in proton exchange membrane fuel cells (PEMFCs) in order to determine the relationship between carbon black content and fuel cell performance. The connection between fuel cell performance and the carbon black content of the carbon fiber paper is discussed, and the effects of carbon black on the carbon fiber paper's thickness, density, and surface resistivity are investigated. When a carbon fiber paper GDL contains 10 wt% phenolic resin and 2% carbon black, and reaction area was 25 cm2 and operating temperature 40 °C, tests show that a carbon electrode fuel cell could achieve 1026.4 mA cm−2 and maximum power of 612.8 mW cm−2 under a 0.5 V load.

Gas diffusion layers (GDL) in proton exchange membrane fuel cells were prepared by graphitization of polyacrylonitrile carbon fiber cloths, to enhance their properties, such as, electrical conductivity, which was examined by electrical tests, X-ray diffraction, and elemental analysis. The results indicated that electrical resistivity declined, L(subscript c) increased, and d002 decreased with an increase in the heat-treatment temperature. Carbon fiber cloths with a higher heat-treatment temperature performed better as GDLs in terms of current density and power density.