Novel carbon paper modified with nanocellulose and phenol formaldehyde resin for proton exchange membrane fuel cell

Carbon paper (CP) is the core component of the gas diffusion layer in proton exchange membrane fuel cell (PEMFC), and the actual operation efficiency of PEMFC was greatly affected by the properties and structure of CP. However, the traditional method of modifying CP with phenol formaldehyde resin (PF) has drawbacks such as high brittleness and poor interface bonding effect. Herein, a novel method for improving the mechanical strength and pore characteristics of CP by modifying PF with nanocellulose is proposed. The results confirmed that the mechanical/electrical properties of CP were greatly changed by the diameters and carboxyl content of nanocellulose. Compared with unmodified CP, the electrical resistivity of CNF10 modified CP was decreased by 23%, and the tensile strength, flexural strength, and gas permeability were increased by 101%, 120%, and 70%, respectively. In addition, the peak power densities of CNF10 modified CP at different anode humidification temperatures (70 °C and 85 °C) were 0.49   W.cm -2 and 0.5   W.cm -2 , respectively, which were 75% and 42% higher than those of unmodified CP, and better than the previous studies (0.458   W.cm -2 ). This simple and controllable modification approach of CP will bring new ideas for developing efficient PEMFC.