DMFC性能稳定性改善措施的探索

Exploration of improvement measures for performance stability of DMFC

从物料性质变化的角度,结合交流阻抗谱和极化曲线,提出缓解直接甲醇燃料电池(DMFC)性能衰减的措施。采用阳极氢离子置换、建立无金属质阳极供料通道和更换甲醇储液瓶等措施,减缓电池性能衰减,机理是补充氢离子,使电池内离子的载流子浓度提高,解决电池内阻增大带来的性能衰减;同时,氢离子的浓度的提高,可向阴极提供更高浓度的反应物氢离子,进一步降低电池的性能衰减;更换无金属质的阳极供料通道,避免"阳离子效应";消除阳极副产物对甲醇电催化氧化的抑制作用。改善后,DMFC在稳定性运行中,功率密度衰减速度减小为初始状态的50%。

From the perspective of changes in the material properties, combined with the AC impedance spectroscopy and polarization curves, measures to ease the performance degradation of direct methanol fuel cell（DMFC） were proposed. By anode H^＋ substitution, establishing metal-free anode feeding channel and replacing of methanol solution bottle, the cell performance degradation was reduced. The carrier concentration of the battery solution was improved by using the additional hydrogen ions, which solved cell performance decay caused by battery internal resistance increases. The increased hydrogen ion concentration provided battery cathode higher reactant concentrations（ hydrogen ion）, and further reduced the performance degradation. The ＂cation effect＂ was avoided by anode feeding channel replacement with metal-free material. It eliminated the inhibitory effect of anode by-products in the eleetrocatalytic oxidation of methanol. After these improvements, the decay rate of the DMFC power density decreased to 50% of the original decay rate value during the stability operation.