Study on direct methanol fuel cell performance modification based on foam carbon diffusion layer

doi:10.11949/0438-1157.20240382

Abstract

Abstract:

Diffusion layer (DL) is an essential structure of a direct methanol fuel cell (DMFC) membrane electrode assembly (MEA), which provides a channel for the mass transfer of reactants from the flow field to the catalytic layer. As the reaction proceeds, the DL also provides a channel for the transport of electrons from the catalytic layer to the flow field. Therefore, the conductivity and surface morphology of the DL affects the overall performance of the fuel cell. The cathode diffusion layer (CDL) based on the foam carbon (FC) material could reduce the contact, charge transfer, and mass transfer resistance between the fuel cell membrane electrode and the current collector plate thanks to the FC's electrical conductivity and three-dimensional network structure. Moreover, the high porosity and small surface contact angle (CA) of FC could also increase the proportion of DMFC cathode catalytic layer exposed to the air and provide extra gas-liquid two-phase channels, which is the better catalyst support. Experimental results show that compared with the DMFC based on traditional carbon paper (CP-DMFC), the maximum power density of the DMFC with FC as the CDL (FC-DMFC) increases from 24.47 mW/cm² to 39.24 mW/cm², the contact resistance decreases from 0.588 Ω to 0.494 Ω, the charge transfer resistance decreases from 2.784 Ω to 1.816 Ω, and the mass transfer impedance decreased from 1.689 Ω to 1.417 Ω. Under a discharging current of 100 mA/cm², the discharge time of FC-DMFC is 60 min, while the discharge time of CP-DMFC is 46 min, and FC as a diffusion layer has a longer discharge time. It shows that the new structure has higher energy efficiency under the same methanol concentration and volume than the conventional structure.

Key words: fuel cell, diffusion layer, foamy carbon, two-phase flow, power density

摘要：

扩散层（DL）是直接甲醇燃料电池（DMFC）膜电极组件（MEA）的重要结构，为反应物从流场到催化层的传质提供通道，随着反应的进行，扩散层也为电子从催化层到流场的传输提供通道，因此，扩散层的导电率和表面形貌影响燃料电池的整体性能。泡沫碳（foam carbon，FC）材料具有优异的导电性能和三维网状结构，将其作为阴极扩散层（CDL），能够降低燃料电池膜电极与集流板间的接触电阻、电荷转移电阻和传质电阻。同时，泡沫碳的较高孔隙率和较小的表面接触角，可增加DMFC阴极催化层暴露在空气中的比例，提供更多的气液两相流道，是较好的催化剂载体。研究结果表明，与传统碳纸比较，泡沫碳作为阴极扩散层的燃料电池峰值功率密度从24.47 mW/cm²提升到39.24 mW/cm²，接触电阻由0.588 Ω降低至0.494 Ω，电荷转移电阻由2.784 Ω降低至1.816 Ω，传质阻抗由1.689 Ω降低至1.417 Ω。在100 mA/cm²的电流放电条件下，FC的放电时长为60 min，碳纸作为DL的放电时长为46 min，FC作为扩散层有更长的放电时间。研究结果说明在相同甲醇浓度以及体积下，新型结构有着比常规结构更高的能量效率。

关键词: 燃料电池, 扩散层, 泡沫碳, 两相流, 功率密度

CLC Number:

TM 911.4

Zhengang ZHAO, Mengyao ZHOU, Dian JIN, Dacheng ZHANG. Study on direct methanol fuel cell performance modification based on foam carbon diffusion layer[J]. CIESC Journal, 2024, 75(S1): 259-266.

赵振刚, 周梦瑶, 金典, 张大骋. 基于泡沫碳扩散层的直接甲醇燃料电池改性研究[J]. 化工学报, 2024, 75(S1): 259-266.

Figures/Tables 11

Table 1 Specific parameters of CP and FC

材料

类型

厚度/

μm

电阻率/

(Ω/cm)

孔隙率/

含碳量/

Fig.1 SEM images of CP and FC

Fig.2 Contact angles

Fig.3 Schematic diagram of MEA (a); CP-MEA, FC-MEA (b); Assembly structural diagram (c); Assembled DMFC (d)

Fig.4 Polarization curves of different methanol concentrations

Table 2 Maximum power density of CP-DMFC and FC-DMFC under different methanol concentrations

甲醇浓度/ (mol/L)	CP-DMFC/(mW/cm²)	FC-DMFC/(mW/cm²)	提升率/%
0.5	18.48	36.00	94.81
1	24.47	39.24	60.36
2	20.65	28.71	39.03
3	15.06	15.58	3.45

Fig.5 Internal losses of the cell

Fig.6 Full-cell equivalent circuit model of DMFC

Fig.7 Electrochemical impedance spectra and fitting curves

Table 3 Parameter identification results

项目	CP-DMFC	FC-DMFC	提升率
R_m/Ω	0.588	0.494	-16.0%
R_i/Ω	1.421	1.437	1.1%
R_ct/Ω	2.784	1.816	-34.8%
R_mt/Ω	1.689	1.417	-16.1%

Fig.8 Constant current discharge curves of CP-DMFC and FC-DMFC under optimal methanol concentration

References 34

1	郭仕权, 孙亚昕, 李从举. 直接甲醇燃料电池(DMFC)阳极过渡金属基催化剂的研究进展[J]. 工程科学学报, 2022, 44(4): 625-640.
	Guo S Q, Sun Y X, Li C J. Research progress in anode transition metal-based catalysts for direct methanol fuel cell[J]. Chinese Journal of Engineering, 2022, 44(4): 625-640.
2	Chen X Y, Li T C, Shen J N, et al. From structures, packaging to application: a system-level review for micro direct methanol fuel cell[J]. Renewable and Sustainable Energy Reviews, 2017, 80: 669-678.
3	严文锐, 张劲, 王海宁, 等. 重整甲醇高温聚合物电解质膜燃料电池研究进展与展望[J]. 化工进展, 2021, 40(6): 2980-2992.
	Yan W R, Zhang J, Wang H N, et al. Advancement toward reforming methanol high temperature polymer electrolyte membrane fuel cells[J]. Chemical Industry and Engineering Progress, 2021, 40(6): 2980-2992.
4	Su S J, Liang J S, Luo Y, et al. A new water management system for air-breathing direct methanol fuel cell using superhydrophilic capillary network and evaporation wings[J]. Energy Conversion and Management, 2021, 246: 114665.
5	Abraham B G, Chetty R. Design and fabrication of a quick-fit architecture air breathing direct methanol fuel cell[J]. International Journal of Hydrogen Energy, 2021, 46(9): 6845-6856.
6	Alias M S, Kamarudin S K, Zainoodin A M, et al. Active direct methanol fuel cell: an overview[J]. International Journal of Hydrogen Energy, 2020, 45(38): 19620-19641.
7	Wang L W, Yin L, Yang W L, et al. Evaluation of structural aspects and operation environments on the performance of passive micro direct methanol fuel cell[J]. International Journal of Hydrogen Energy, 2021, 46(2): 2594-2605.
8	Xing L, Shi W D, Su H N, et al. Membrane electrode assemblies for PEM fuel cells: a review of functional graded design and optimization[J]. Energy, 2019, 177: 445-464.
9	马小杰, 方卫民. 质子交换膜燃料电池双极板研究进展[J]. 材料导报, 2006, 20(1): 26-30.
	Ma X J, Fang W M. Research and progress of bipolar plate for proton-exchange membrane fuel cell[J]. Materials Review, 2006, 20(1): 26-30.
10	张立昌, 蔡超, 谭金婷, 等. 质子交换膜燃料电池微孔层在反极过程中的耐久性研究[J]. 材料导报, 2022, 36(14): 67-73.
	Zhang L C, Cai C, Tan J T, et al. Study on the durability of the microporous layer of proton exchange membrane fuel cell during the voltage reversal process[J]. Materials Reports, 2022, 36(14): 67-73.
11	Ali Abdelkareem M, Sayed E T, Nakagawa N. Significance of diffusion layers on the performance of liquid and vapor feed passive direct methanol fuel cells[J]. Energy, 2020, 209: 118492.
12	Zhao Z G, Wang Z T, Li K, et al. Cathode diffusion layer and current collector with slotted foam stainless steel for a micro direct methanol fuel cell[J]. RSC Advances, 2022, 12(44): 28738-28745.
13	Rambabu G, Bhat S D, Figueiredo F M L. Carbon nanocomposite membrane electrolytes for direct methanol fuel cells—a concise review[J]. Nanomaterials, 2019, 9(9): 1292.
14	高帷韬, 雷一杰, 张勋, 等. 质子交换膜燃料电池研究进展[J]. 化工进展, 2022, 41(3): 1539-1555.
	Gao W T, Lei Y J, Zhang X, et al. An overview of proton exchange membrane fuel cell[J]. Chemical Industry and Engineering Progress, 2022, 41(3): 1539-1555.
15	Ali Abdelkareem M, Sayed E T, Mohamed H O, et al. Nonprecious anodic catalysts for low-molecular-hydrocarbon fuel cells: theoretical consideration and current progress[J]. Progress in Energy and Combustion Science, 2020, 77: 100805.
16	Tan W C, Saw L H, Thiam H S, et al. Overview of porous media/metal foam application in fuel cells and solar power systems[J]. Renewable and Sustainable Energy Reviews, 2018, 96: 181-197.
17	Yuan W, Tang Y, Yang X J, et al. Porous metal materials for polymer electrolyte membrane fuel cells—a review[J]. Applied Energy, 2012, 94: 309-329.
18	Zhao Z G, Zhang F, Zhang Y H, et al. Performance optimization of μDMFC with foamed stainless steel cathode current collector[J]. Energies, 2021, 14(20): 6608.
19	Braz B A, Moreira C S, Oliveira V B, et al. Effect of the current collector design on the performance of a passive direct methanol fuel cell[J]. Electrochimica Acta, 2019, 300: 306-315.
20	Braz B A, Oliveira V B, Pinto A M F R. Experimental studies of the effect of cathode diffusion layer properties on a passive direct methanol fuel cell power output[J]. International Journal of Hydrogen Energy, 2019, 44(35): 19334-19343.
21	Braz B A, Oliveira V B, Pinto A M F R. Optimization of a passive direct methanol fuel cell with different current collector materials[J]. Energy, 2020, 208: 118394.
22	Hao W B, Ma H Y, Sun G X, et al. Magnesia phosphate cement composite bipolar plates for passive type direct methanol fuel cells[J]. Energy, 2019, 168: 80-87.
23	Zhu Y L, Zhang X J, Li J Y, et al. Three-dimensional graphene as gas diffusion layer for micro direct methanol fuel cell[J]. International Journal of Modern Physics B, 2018, 32(12): 1850145.
24	Zhang X Y, Huang Y X, Zhou X L, et al. Characterizations of carbonized electrospun mats as diffusion layers for direct methanol fuel cells[J]. Journal of Power Sources, 2020, 448: 227410.
25	Alrashidi A, Liu H T. Laser-perforated anode gas diffusion layers for direct methanol fuel cells[J]. International Journal of Hydrogen Energy, 2021, 46(34): 17886-17896.
26	朱逸涵. 泡沫碳基柔性自支撑材料的制备及其电化学和微波吸收性能研究[D]. 镇江: 江苏大学, 2022.
	Zhu Y H. Carbon foam-based flexible self-standing materials: synthesis, electrochemical and microwave absorbing properties[D]. Zhenjiang: Jiangsu University, 2022.
27	闫涛. 三维泡沫碳材料的制备、改性及其电化学性能研究[D]. 天津: 天津大学, 2020.
	Yan T. Preparation, modification and electrochemical performance of threedimensional carbon foams[D]. Tianjin: Tianjin University, 2020.
28	Zhu Y H, Wang D F, Yan X H, et al. Rational design for Mn₃O₄@carbon foam nanocomposite with 0D@3D structure for boosting electrochemical performance[J]. Energy & Fuels, 2020, 34(11): 14924-14933.
29	Zhu Y H, Wang D F, Yan X H, et al. Vertical, dense and uniform V₂O₅ nanoneedle arrays on carbon foam for boosting electrochemical performance[J]. Journal of Energy Storage, 2021, 37: 102492.
30	Okech G, Emam M, Mori S, et al. Enhancing the performance of direct methanol fuel cells using new cathode flow field designs: an experimental investigation[J]. International Journal of Hydrogen Energy, 2024, 57: 161-175.
31	Okech G, Emam M, Mori S, et al. Experimental study on the effect of new anode flow field designs on the performance of direct methanol fuel cells[J]. Energy Conversion and Management, 2024, 301: 117988.
32	Li Y, Zhang X L, Nie L, et al. Stainless steel fiber felt as cathode diffusion backing and current collector for a micro direct methanol fuel cell with low methanol crossover[J]. Journal of Power Sources, 2014, 245: 520-528.
33	李洋. 金属基微型直接甲醇燃料电池关键技术研究[D]. 哈尔滨: 哈尔滨工业大学, 2019.
	Li Y. Research on the key technologies of metal based micro direct methanol fuel cell[D]. Harbin: Harbin Institute of Technology, 2019.
34	Yuan T, Zou Z Q, Chen M, et al. New anodic diffusive layer for passive micro-direct methanol fuel cell[J]. Journal of Power Sources, 2009, 192(2): 423-428.

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