The whole process, bubble dynamic analysis in two-phase transport of the passive miniature direct methanol fuel cells

Yuan, Zhenyu; Zuo, Kaiyuan; Cao, Cheng; Chen, Shuxuan; Chuai, Wenhui; Guo, Zhongming

doi:10.1016/j.jpowsour.2019.01.088

Cited by 28 publications

(14 citation statements)

References 35 publications

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“…Globally, the research for improved power supply systems has been stimulated by the ever-increasing market of portable electronic devices (1–50 W), such as smartphones, laptops, tablets, global positioning systems, and so forth . Direct methanol fuel cells (DMFCs) can meet the demanding requirements perfectly with the high energy density (5100 Wh L –1 ), simple structure, and easy supplement. − Moreover, DMFCs can be operated in a passive mode by the elimination of auxiliary devices, with the fuel and oxygen provided by diffusion and natural convection . This kind of passive design simplifies the cell structure greatly; however, it leads to a poor mass transport, making its performance worse than those running in the active mode …”

Section: Introductionmentioning

confidence: 99%

Constructing a Cathode Catalyst Layer of a Passive Direct Methanol Fuel Cell with Highly Hydrophilic Carbon Aerogel for Improved Water Management

Wen

Hou

Zhang

et al. 2019

ACS Appl. Mater. Interfaces

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Nitrogen-doped porous carbon materials show excellent water adsorption ability by forming strong hydrogen bonding between water molecules and the doped atoms. When these porous carbon materials are used to construct a water management layer (WML) of a passive direct methanol fuel cell (DMFC), high water concentration and hydraulic pressure formed inside the cathode catalyst layer would facilitate the water recovery from cathode to anode. In this paper, a highly hydrophilic nitrogen-doped carbon aerogel was synthesized by the carbonization of hydrogel precursors composed of resorcinol, formaldehyde, and graphene oxide under ammonia, and it was used for the first time to construct the WML for liquid-feed and vapor-feed passive DMFCs. The results show that the WML significantly improves the output performance of the liquid-feed DMFC by enhancing the water recovery, which is characterized and proved by the smaller cathode polarization, the slightly increased anode polarization, and a released cathode water flooding situation. A new method was also proposed to study the in situ methanol crossover of DMFCs, which confirmed that the methanol crossover during the discharge was reduced by the WML. As for the vapor-feed DMFCs, the WML reduces both the cathode and anode polarizations significantly, which increases the output performance greatly. This study opens a new window for the design and optimization of the membrane assembly electrode of DMFCs.

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Section: Introductionmentioning

confidence: 99%

Constructing a Cathode Catalyst Layer of a Passive Direct Methanol Fuel Cell with Highly Hydrophilic Carbon Aerogel for Improved Water Management

Wen

Hou

Zhang

et al. 2019

ACS Appl. Mater. Interfaces

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“…The calculated results are in good agreement with our previous experimental results. The correctness of the simulation could be proved [26,27,28]. The power density of DMFC increased gradually when the ambient temperature increased from 298 K to 323 K at the concentration of 3 M; and when the ambient temperature was higher than 323 K, the performance of DMFC decreased.…”

Section: Discussionmentioning

confidence: 99%

Thermal Layout Analysis and Design of Direct Methanol Fuel Cells on PCB Based on Novel Particle Swarm Optimization

et al. 2019

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As a new energy technology, the fuel cell has developed rapidly, and its performance has been continuously improved. Fuel cell stacks composed of multiple single cells are gradually being used in portable electronic products. Since the performance of fuel cells cannot be optimal at room temperature, it is critical to research cell temperature characteristics and heat distributions in applications. In this paper, the effects of temperature and charge transfer coefficient and the relationship between exchange current density and output voltage were analyzed by the mathematical model of direct methanol fuel cells. Moreover, to optimize the thermal layout of the fuel cell stack in the printed circuit board (PCB) substrate, the idea of a fuel cell as a device was proposed innovatively, and the corresponding thermal optimization strategy was analyzed. A novel particle swarm optimization algorithm was used to detect the optimal layout of fuel cells of different specifications on the same substrate. The three-dimensional thermal simulation model was used to obtain the temperature data and verify the optimization results.

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“…In order to verify the model precision, one passive μDMFC is designed and fabricated, and a detailed experimental test is carried out in our paper published previously. 20 It will not be described repeatedly in this paper. The experimental cell is set to the same simulation area, and the experimental results are compared with the simulation results to prove the accuracy of the simulation.…”

Section: Model Verificationmentioning

confidence: 99%

“…The magnitude of these forces determines the growth state of the bubble, and the process of detachment of the bubble. 20 In terms of the overall mass transfer of the DMFC, a quasi-twodimensional numerical model was established by Kablou et al 21 to predict the two-phase flow behavior of the DMFC anode, and the pressure drop, flow rate, and methanol concentration changes in the fuel channel under different porosities were analyzed. Turkmen et al 22 investigated the relationship between the channel pressure drop caused by methanol flow and the geometry of the flow channel on the anode side of the DMFC.…”

Section: Introductionmentioning

confidence: 99%

The nonisothermal two‐phase model based on mixed convection in passive μDMFC

Wang

Yuan

2020

Asia-Pacific J Chem Eng

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During the working process of passive microdirect methanol fuel cell (μDMFC), the characteristics of inverse movement between two-phase substances are quite distinct from macro gas-liquid inverse movement, including electrochemical reactions, electrical drag, multicomponent diffusion, evaporation, and condensation. Due to the complexity of internal operation system of μDMFC, it is difficult to monitor and analyze dynamic property currently only by experiment. Therefore, in this paper, an integrated and accurate prediction model to explore two-phase transmission is build up, to investigate different effects by varying parameters, and to maximize cell performance. First, the accuracy of the simulation is proved by experimental tests. Then, a comprehensive, two-phase mass transfer model of passive DMFC is established. The methanol concentration, oxygen concentration, cathode and anode flow velocity and pressure distribution, potential distribution, and anode saturation distribution are studied. Moreover, a nonisothermal model considering the natural convection in the anode is established, the velocity field in the tank, the temperature distribution of the cell, the methanol distribution, and the temperature distribution on the anode catalyst layer is optimized. The research results can provide accurate theoretical support for fuel cell internal component preparation and μDMFC portable applications. K E Y W O R D Sgas-liquid inverse movement, microdirect methanol fuel cell, nonisothermal model

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The whole process, bubble dynamic analysis in two-phase transport of the passive miniature direct methanol fuel cells

Cited by 28 publications

References 35 publications

Constructing a Cathode Catalyst Layer of a Passive Direct Methanol Fuel Cell with Highly Hydrophilic Carbon Aerogel for Improved Water Management

Constructing a Cathode Catalyst Layer of a Passive Direct Methanol Fuel Cell with Highly Hydrophilic Carbon Aerogel for Improved Water Management

Thermal Layout Analysis and Design of Direct Methanol Fuel Cells on PCB Based on Novel Particle Swarm Optimization

The nonisothermal two‐phase model based on mixed convection in passive μDMFC

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