摘要
通过单电池在不同低温操作条件下进行自启动试验,以考察电池在低温环境下的自启动能力。电池的操作条件模拟了发动机启动时空气被压缩引起的温升对启动的影响。通过极化曲线、SEM等考察了电池性能衰减的状况及衰减机理。结果表明:仅仅通过空压机压缩空气对电池进行预热在较低温度下启动发动机难以成功;操作条件对电池自启动有较大影响,加大进气流量、降低启动负载电流密度可以提高电池启动能力;电池在-5℃对负载的变化适应性较强,而在-7℃对负载的变化变得非常敏感;多次冷启动后,催化层表面发生了龟裂;碳纸表面PTFE颗粒发生了脱离,构成空隙骨架的碳纤维变得光洁,碳纤维在冰的冻涨应力的作用下被折断,扩散层的排水、导气能力降低,使得电池性能衰减。
This work studied the start-up ability of a single cell under subzero temperature with different operating conditions.Novelty lies in that the cell operating conditions simulated the effect of the temperature rise of air caused by the compression of the air compressor of the engine when it starts up.Performance decay was investigated by means of polarization curves and scanning electron microscopy（SEM）.Results show that the engine would be difficult to start up successfully under lower temperature if preheated only by the air＇s compression of the compressor;increasing air flow and reducing the current density could improve the startup ability of the fuel cell;the fuel cell had strong adaptability to the load changing at-5 ℃,but became very sensitive at-7 ℃.After several times cold-start,the surface of catalyst layer cracked,the particles of PTFE gas diffusion layer（GDL） were divorced from the surface of the carbon fibers which made of the skeleton of the GDL;also some carbon fibers broke due to the expansion of icing,which made the water drainage and gas conduct capability of the GDL reduced.All these caused the performance of the PEMFC degraded.
出处
《武汉理工大学学报》
CAS
CSCD
北大核心
2011年第1期151-155,共5页
Journal of Wuhan University of Technology
基金
国家"863"重点项目(2008AA11A106)
湖北省自然科学基金(2009CDB407)
