超级电池负极材料的电化学行为

利用循环伏安、阴极极化等测试手段研究超级电池负极中活性炭(AC)电极在铅酸电池测试环境中的电化学行为,比较AC电极与Pb电极在相同电位区间下的极化特性,考察-0.9～-0.4 V(vs.SCE)电位范围内AC及Pb并联电极的电化学特性,并对循环后并联电极中的AC电极进行电子能谱(EDX)分析。研究结果表明:活性炭在-0.9～-0.4 V电位范围内表现出双电层电容特性;在10 mV/s扫描速度下析氢电流随着硫酸浓度的增大而增大,比容量在硫酸浓度为3 mol/L时最大;在浓度为5 mol/L的硫酸中,活性炭的比容量随着扫描速度的增大而减小;在相同电位下,AC电极的析氢较Pb电极的析氢严重;AC与Pb的并联电极既表现出Pb电极的法拉第电池特性,又表现出AC电极的双电层电容与析氢特性。

Electrochemical behavior of ultrabattery negative electrode material

Cyclic voltammetry and cathodic polarization tests were used to investigate the electrochemistry behaviors of activated carbon(AC) for ultrabattery negative electrode in the testing environment of lead acid battery.Comparison between the polarization properties of AC electrodes and Pb electrodes in some potentials was made,and the electrochemical characteristics of parallel electrode from-0.9 V to-0.4 V(vs.SCE) were also investigated.EDX was used to analyze the element components of AC in parallel electrode after three cycles in cyclic voltammetry tests.The results show that AC electrode presents character of double layer capacitance from-0.9 V to-0.4 V,and the hydrogen evolution current increases with the increase of the sulfuric acid concentration at the scan rate of 10 mV/s.The largest specific capacitance is obtained in 3 mol/L sulfuric acid.In 5 mol/L sulfuric acid,the specific capacitance decreases with the increase of the scan rate.At the same potential,the AC electrode is much easier in producing hydrogen in 5 mol/L sulfuric acid than that of the Pb electrode.The parallel electrode has both the effects of faraday battery and double layer capacitor characteristics.