百瓦级一体式再生燃料电池堆研究

对百瓦级一体式再生燃料电池堆(URFC)的电性能和燃料电池(FC)/水电解(W E)双模式循环稳定性进行测试研究。所研制的百瓦级URFC电池堆双模式工作电性能优良,循环性能稳定。燃料电池模式工作条件下:电流密度为500 mA/cm 2时,单体电池平均工作电压0.789 V,输出功率236 W;电流密度为1 000 mA/cm 2时,单体电池平均工作电压0.681 V,输出功率409 W。水电解模式工作条件下:电流密度为1 000 mA/cm 2时,单体电池平均工作电压1.628V,产生标准状态下氢气的耗能量为4.26 kW h/m 3。电流密度为500 mA/cm 2时,URFC电池堆充放电循环电压效率为51.5%。单体电池电压方差和计算结果表明,在工作电流密度0～400 mA/cm 2的窗口区间内,单体电池电压具有相对最好的均匀一致性。在100 h/20次的FC/WE双模式循环试验中,URFC电池堆性能衰减平均为1.70%。

Research on hectowatt stack of unitized regenerative fuel cell

In the paper,the hectowatt stack of unitized regenerative fuel cell was developed and validated,the cycling performance and polarization curves of URFC stack in the hydrogen and oxygen fuel cell and water electrolysis modes were investigated.It was verified that the bifunctional performance and the cycling stability of the stack during URFC operation were very promising.The average cell voltages were 0.789 V and 0.681 V at the current density of 500 mA/cm2 and 1 000 mA/cm2 in fuel cell mode,respectively;the stack electrical power reached 236 W at the current density of 500 mA/cm2.The average cell voltage was 1.628 V at the current density of 1 000 mA/cm2 in water electrolysis mode,and the consumption electrical energy of hydrogen production under normal condition was 4.26 kWh/m3.The round-trip energy conversion efficiency of URFC stack was 51.5% at the current density of 500 mA/cm2.The variance analysis was adopted to evaluate the uniformity of individual cell voltages in the stack.The calculated results show the stack has a lower cell to cell voltage variation at the current density range from 0 to 400 mA/cm2.The degradation rate of URFC stack is 1.70% during 20 cycles for 100 h in both fuel cell and water electrolysis modes at the current density of 500 mA/cm2.