HBF_4溶液中全铅液流电池

All-Lead Redox Flow Battery in a Fluoroboric Acid Electrolyte

报道了一种HBF_4水溶液中的全铅液流电池,正、负电极电解液均采用Pb(BF_4)_2的HBF_4水溶液.在酸性的四氟硼酸铅电解液中考察了石墨电极和玻碳电极作为工作电极的循环伏安性能,石墨电极较适于用作全铅液流电池的正、负电极.采用石墨电极作为电池的正、负电极并在四氟硼酸铅酸性电解液中进行充放电实验,其中Pb(BF_4)_2浓度分别为0.5、1.0和1.5 mol·L^(-1),且保持游离的HBF_4浓度为1.0 mol·L^(-1).该电池为单液流电池,不需要隔膜分隔正、负极的电解液,电流密度为10、20和40 mA.cm^(-2),当限定充电容量为7.0 mAh.cm^(-2),放电电压截止到1.0 V时,平均库仑效率大于87%,平均能量效率大于68%;当电解液采用1.0或1.5 mol·L^(-1) Pb(BF_4)_2+1.0 mol·L^(-1)HBF_4水溶液时,在10及20 mA.cm^(-2)电流下的能量效率最高可超过74%.

An all-lead redox flow battery in a fluoroboric acid electrolyte is proposed.The same electrolyte was used as both the negative and positive electrodes,and it consists of a high concentration solution of Pb（BF_4）_2 in aqueous fluoroboric acid,i.e.,0.1,0.5,1.0 and 1.5 mol·L^（-1） Pb（BF_4）_2 in 1.0 mol·L^（-1） HBF_4.The properties of the graphite and glassy carbon electrodes for both the positive and negative electrodes as current collectors were compared using cyclic voltammetry.We found that the graphite substrate was better than glassy carbon for both the negative electrode and the positive electrode.The all-lead redox flow battery was constructed using graphite substrates as both the positive and negative electrodes with a single electrolyte flow passing though the two electrodes.The performance of the batteries was evaluated using the constant current charge/discharge technique.Typically,an average coulombic efficiency of above 87%and an average energy efficiency of above 68%were obtained.An average energy efficiency of above 74%was achieved with electrolyte containing 1.0 or 1.5 mol·L^（-1） Pb（BF_4）_2 ＋ 1.0 mol·L^（-1） HBF_4 at current densities of 10 and 20 mA·cm^（-2）.