Constructing a graphene-contained layer in anode to improve the performance of direct methanol fuel cells using high-concentration fuel

ABSTRACT

A novel membrane-electrode structure is conceived and prepared in this work, where a graphene-contained layer is constructed between anode catalyst layer and membrane, also the material composition in this layer is optimized to improve the performance of a direct methanol fuel cell (DMFC) with high-concentration fuel. The polarization test shows that the pristine graphene layer could reduce the methanol crossover, while causing a slight decrease in performance. After adding Nafion ionomer binder in the graphene layer, the peak power density of the electrode fed with 8 M methanol reaches 17.75 mW cm⁻², which is increased by 12.36% and 82.69% compared with the conventional electrode and the electrode without any binder in the graphene layer, respectively. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) results show that for the graphene-contained layer including Nafion ionomer binder, the charge transfer resistance is only one-fifth of that without binder in the graphene layer, and the anode electrochemical active surface area (ECSA) is increased by 40.16%. These results indicate that the anode electrode with a graphene-contained layer using Nafion ionomer as the binder can effectively improve the cell performance with high-concentration fuel, which is beneficial to increase the energy density of a DMFC system.

KEYWORDS:

• Direct methanol fuel cell (DMFC)
• graphene layer
• Nafion binder
• high concentration
• cell performance

Disclosure statement

We have no conflict of interest to declare.

Additional information

Funding

The work described in this paper was fully supported by Grants from the NSFC, China (No. 51676092, No. 21676126),State Key Laboratory of Engine at Tianjin University (No. K2020-14), Six-Talent-Peaks Project in Jiangsu Province (2016-XNY-015), High-Tech Research Key Laboratory of Zhenjiang City (No. SS2018002), and a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD), China.