A CNT-MEA compound structure of micro-direct methanol fuel cell for water management

In this paper, a novel micro-direct methanol fuel cell (μ-DMFC) with a CNT-MEA compound structure is purposed for water management. The CNT paper as water transmittal layer is sandwiched between the gas diffusion layer (GDL) and cathode current collector. This new water transmittal layer can passively prevent flooding in the cathode avoiding parasitic power loss and ensure efficiency of oxygen mass transport by humidify dry oxygen. The CNT paper is fabricated by aggregate of carbon nanotubes filtering mixture suspension of MWNTs and Triton X-100 surfactant and the other components of μ-DMFC with a CNT-MEA are produced using MEMS technologies. To analyze the performance of μ-DMFC with a CNT-MEA compound structure, all the experiments are fed with 3.0 M methanol solution and flow rates of 1 ml/min at a temperature of 40 °C. The experiment result shows that the μ-DMFC with CNT-MEA exhibits significantly higher performance than the conventional μ-DMFC without CNT-MEA, showing the peak power density is 46 mW cm−2. Moreover, during the long-term operation of the μ-DMFC with CNT-MEA, there is no water flooding on the cathode surface. Therefore, our water management system achieves the goal of performance enhancement without introducing parasitic losses.

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► A carbon nanotube (CNT)–MEA compound structure of μ-DMFC is proposed.
► The CNT paper as water transmittal layer can balance water content in cathode.
► The performance of μ-DMFC with CNT-MEA is better than that without CNT.
► The CNT-MEA can avoid water flooding on the cathode.