类超晶格结构:有序性传质赋予燃料电池高品质输出性能（英文）

质子交换膜燃料电池(PEMFC)是一种强耦合、复杂非线性、动态的、多输入多输出的能量转换装置,不容易达到或保持理想的工作状态。在动态的PEMFC的工作状态下,其输出的电流和电压是振动的、不稳定的,会对负载的使用和寿命造成很大的影响,严重时亦可损坏负载。该波动的电流或电压输出不仅直接决定着发电系统的成本,而且影响着有效的能量转换效率及电子原件和设备的寿命。基于此,本工作针对燃料电池动态特性及动态排水空间受限导致其电流不规则波动,进而影响输出电能品质和燃料电池系统及其他电子元件的寿命和维护成本等问题,开发了一种外延生长的方法制备排水空间可调控的抗溺水电极,通过调控载体的成核位点密度,形成一种具有不同排水空间的类超晶体结构微米级铂基催化剂。该催化剂制备的电极不仅表现出极佳的抗溺水性,在极低的电流振幅(25 mA·cm^-2)下持续稳定的输出高品质电能,同时提高了铂的利用率,使其组成的MEA比功率密度达到11.69 W·mg_Pt^-1,表现出极高的应用潜力。

Supperlattice-Like Structure: Ordered Mass Transfer Endowing High Quality Output of Fuel Cell

The current or voltage fluctuation in fuel cell operation is harmful to the fuel cell system and power application equipment. Here, we report a technique to eliminate such a fluctuation by the aid of new type of catalysts, superlattice-like mesoporous PtCo catalysts. The current fluctuation in fuel cells catalyzed by two invented catalysts are fixed at as low as 25 mA·cm^-2 with a power of 0.75 W·cm^-2 or 120 mA·cm^-2 with a power of 1.01 W·cm^-2, and no noticeable current decay was detected over 100 h. By contrast, a cell catalyzed by conventional Pt/C catalysts with the same Pt loading delivered a current fluctuation as large as 180 mA·cm^-2 even at low power output of 0.30 W·cm^-2, which also showed 32% current decay rate in 50 h. The superlattices-like mesoporous structure not only enhances the mass transfer and depresses the water flooding but also effectively increases the Pt utilization within its 3D carbon frameworks. Its power output was as high as 11.69 W·mg_Pt^-1 (MEA), which is 46.1% higher than the 2025 target of DOE, USA, 8.0 W·mg_Pt^-1(MEA).