Cai Fengyang, Cai Shanshan, Tu Zhengkai, Chan Siew Hwa
School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China.
Energy Research Institute, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 637553, Singapore.
Adv Sci (Weinh). 2025 Jul;12(26):e2501825. doi: 10.1002/advs.202501825. Epub 2025 Apr 25.
The dynamic performance of proton exchange membrane fuel cells (PEMFCs) under high current density (HCD) rapid loading is crucial for commercialization. This study introduces an advanced temperature difference (TD) design featuring an in-plane temperature gradient. By reconstructing cooling channels, optimal temperature distribution across the upstream, midstream, and downstream regions achieves balanced water-gas-heat conditions, enhancing the dynamic response of PEMFCs under HCD loading. Various TD designs are investigated across a broad humidity range, innovatively focusing on key moments involving load initiation, transient voltage minimum (TVM), and steady-state voltage (SSV). Comprehensive evaluations encompassing voltage response and energy consumption assess TD enhancements, while electrochemical impedance spectroscopy (EIS) and local current density monitoring further elucidate underlying mechanisms. Results show the positive temperature difference (PTD) design enhances hydration upstream and mitigates flooding downstream under low-humidity conditions. Conversely, the negative temperature difference (NTD) design tends to dehydration upstream and flooding downstream. At RH = 35%, the PTD design increases TVM by 18.2%, decreases voltage undershoot (VU) by 12.5%, raises SSV by 5.67%, and enhances electricity output by 7%. As humidity increases, the positive effect of the PTD design gradually weakens, though it still benefits the current density distribution uniformity.
质子交换膜燃料电池（PEMFC）在高电流密度（HCD）快速加载下的动态性能对商业化至关重要。本研究引入了一种先进的温差（TD）设计，其具有面内温度梯度。通过重构冷却通道，在上游、中游和下游区域实现了最佳温度分布，达到了水 - 气 - 热条件的平衡，增强了PEMFC在HCD加载下的动态响应。在较宽的湿度范围内研究了各种TD设计，创新性地关注了包括负载启动、瞬态电压最小值（TVM）和稳态电压（SSV）等关键时刻。涵盖电压响应和能量消耗的综合评估评估了TD增强效果，而电化学阻抗谱（EIS）和局部电流密度监测进一步阐明了潜在机制。结果表明，正温差（PTD）设计在低湿度条件下增强了上游的水化作用并减轻了下游的水淹。相反，负温差（NTD）设计往往导致上游脱水和下游水淹。在相对湿度 = 35% 时，PTD设计使TVM增加了18.2%，电压下冲（VU）降低了12.5%，SSV提高了5.67%，并使电力输出提高了7%。随着湿度增加，PTD设计的积极效果逐渐减弱，不过它仍然有利于电流密度分布的均匀性。
