Abstract:

For proton exchange membrane fuel cell (PEMFC) power supply system after shutdown, fuel cell open circuit high voltage is considered to be an important factor causing low battery performance and shortened life. This is mainly because after shutdown of PEMFC power system, fuel cell is in an open state. Residual hydrogen on the anode side reacts with air on the cathode side and the battery is at open circuit high voltage which is maintained for a long time. It is easy to cause oxidation of catalyst carbon carrier and shedding of distributed platinum (Pt) particles, and consequently decayed fuel cell performance and shortened life expectancy. Aiming at minimizing the time of shutdown open circuit high voltage and accelerating consumption of residual hydrogen on the anode, a shutdown strategy of PEMFC power system was proposed, and the influence of direct shutdown and shutdown strategy on PEMFC output characteristics was studied through experiments. The effectiveness of the shutdown strategy was verified, and references guidance was provided for protective shutdown strategy of PEMFC power system.

Key words: proton exchange membrane fuel cell, oxidation, carbon support, corrosion, shutdown strategy

摘要：

质子交换膜燃料电池(PEMFC)电源系统在停机后,燃料电池开路高电压被认为是造成电池性能下降和寿命缩短的重要因素。这主要是因为PEMFC电源系统停机后,燃料电池处于开路状态,阳极侧残留的氢气和阴极侧的空气发生电化学反应,电池电压为开路高电压且维持在开路电压的时间比较长,这容易引起催化剂碳载体发生氧化,使分布在载体上的铂(Pt)颗粒脱落,造成燃料电池性能衰减以及寿命缩短。以最大程度缩短停机后开路高电压的时间和加快阳极侧残留氢气的消耗速度为目标,提出了一种PEMFC电源系统的停机策略,通过实验分别研究了直接停机和停机策略停机对PEMFC输出特性的影响。以该停机控制策略为基础,通过实验验证了该停机策略的有效性,为提出保护性的PEMFC电源系统停机控制策略提供了参考性指导。

关键词: 质子交换膜燃料电池, 氧化, 碳载体, 腐蚀, 停机策略