泡沫铅对VRLA电池负极活性物质结构及性能影响

0引言随着36V/42V汽车电源系统的提出,新一轮汽车用电池的竞争不断加剧。从目前情况看,铅酸电池由于具有成本低廉,使用可靠,原材料来源丰富,铅回收率可高达98%等优点,因此成为电动车电源最实际的选择之一1]。但作为电动车用电池,需要克服其比能量低、充电接受能力差和负极硫酸盐化等缺点。为此各国科学家开展了大量的研究工作。最近报道用铸造多孔体作为敞口铅酸电池的集流体,它的比表面积为14cm2·cm-3,正极活性物质利用率上升到50%,远高于传统的铸造板栅2]。在铅酸电池集流体研究领域里另一个重大进步,就是以R V C(R etic-ulated V i…

Effects of Lead Foam on Structure and Characteristic of Negative Active Materials in VRLA Batteries

The surface morphology and composition of negative active material (NAM) both on the cast grid and on lead foam grid at the state of charge and discharge, in valve-regulated lead acid (VRLA) battery, were characterized by SEM and XRD, respectively. Moreover, the specific surface area and electrochemical impedance of the negative active material for both negative electrode grids were studied by chronoamperometry and EIS. The result indicates that after lots of cycles, compared with the cast grid, the sponge lead of the lead foam negative plate is smaller; the specific surface area increases by about 16%; the residual PbSO₄ on the surface of the electrode is less at the state of charge. At the state of discharge, PbSO₄ crystals on the surface of the negative plate of lead foam are smaller, and the specific surface area increases to 209%. EIS analysis shows that compared with the negative plate of cast grid, no matter what state the negative plate of lead foam is at, the electrochemical impedance of the material is lower.