Investigation of thin/well-tunable liquid/gas diffusion layers exhibiting superior multifunctional performance in low-temperature electrolytic water splitting
Investigation of thin/well-tunable liquid/gas diffusion layers exhibiting superior multifunctional performance in low-temperature electrolytic water splitting
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DOI：
10.1039/c6ee02368a
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发表时间：
2017-01-01
影响因子：
32.5
通讯作者：
Zhang, Feng-Yuan
中科院分区：
文献类型：
--
作者：
Kang, Zhenye;Mo, Jingke;Zhang, Feng-Yuan
液/气扩散层（LGDL）位于催化剂层（CL）和双极板（BP）之间，在增强质子交换膜电解槽（PEMEC）水分解性能方面发挥着重要作用。它们预计能够以最小的电压、电流、热、界面和流体损失同时传输电子、热量和反应物/产物。在这项研究中，首次对具有直通孔和明确的孔形态的薄钛基LGDL进行了全面研究。与已发表的文献相比，孔径为 400 mm、孔隙率为 0.7 的新型 LGDL 在 2 A cm(-2) 和 80 摄氏度下实现了 1.66 V 的最佳性能。薄的/可调性良好的钛基 LGDL 显着降低了欧姆和活化损耗，并且发现孔隙率对性能的影响比孔径更显着。此外，还建立了适当的等效电路模型来量化孔隙形态的影响。通过与高速微尺度可视化系统相结合，可以观察到 PEMEC 中心的快速电化学反应现象。观察到的反应提供了合理且开创性的数据，阐明了孔隙率和孔径大小对 PEMEC 性能的影响。这项研究可以为未来高效、低成本氢能的研发提供新的指导。
Liquid/gas diffusion layers (LGDLs), which are located between the catalyst layer (CL) and bipolar plate (BP), play an important role in enhancing the performance of water splitting in proton exchange membrane electrolyzer cells (PEMECs). They are expected to transport electrons, heat, and reactants/ products simultaneously with minimum voltage, current, thermal, interfacial, and fluidic losses. In this study, the thin titanium-based LGDLs with straight-through pores and well-defined pore morphologies are comprehensively investigated for the first time. The novel LGDL with a 400 mm pore size and 0.7 porosity achieved a best-ever performance of 1.66 V at 2 A cm(-2) and 80 degrees C, as compared to the published literature. The thin/well-tunable titanium based LGDLs remarkably reduce ohmic and activation losses, and it was found that porosity has a more significant impact on performance than pore size. In addition, an appropriate equivalent electrical circuit model has been established to quantify the effects of pore morphologies. The rapid electrochemical reaction phenomena at the center of the PEMEC are observed by coupling with high-speed and micro-scale visualization systems. The observed reactions contribute reasonable and pioneering data that elucidate the effects of porosity and pore size on the PEMEC performance. This study can be a new guide for future research and development towards high-efficiency and low-cost hydrogen energy.