Ultrafine Metal Powder On The Cathode Active Material Of Lead-acid Batteries

Lead-acid battery has been used for one hundred and fifty years since it was invented. It can not be replaced in battery industry for its some unique merits ever since it was invented. With the development of communications, electricity and electric vehicles, the studys of has heen rising another hotspot in the recent years. It is of great importance and realistic significance to research on the lead-acid battery as far as the recent situation is concerned. Although the technology of lead-acid battery has matured, its active material generally has lower efficiency. In particular the utilization of positive active material is only 50～70% of the theoretical value. And the performance of the positive pole decides the whole battery performance.In the experiment, we try to find out some ways to improve the performance of the positive pole through the study of positive active material. In accordance with the additive on the active material's mechanism, an additive or several additives as a common compound additive added to the positive active material, maked the battery and compared with the blank battery not with the additive.From the composition of the positive active material form, battery charging and discharging mechanism to start, we ues materials science point of view to explain how to improve the capacity and inhibit the battery premature.We have done a serial of experiments to study the lead-acid battery positive electrode active material and corrosion product of the grid with the aids of the measurements such as constant current charge/recharge, XRD, SEM and so on. Through the experiment we have found that SnO2 can improve the discharge capacity and utilization of active material as positive electrode active material additives of the lead-acid battery.SnO2 adding to PAM change the structure of the active, so that the spherical particles become a thin rod-like structure which enhance the conductivity and connection strength of the active material. This structure can also keep the active material in the charge-discharge process off easy, increase theβ-PbO2 of the diffraction peak intensity and inhibit the generation of a-PbO2. The addition of ultra-fine Sb2O3 make the surface area, the response interface and the diffusion coefficient of active substance increasing, weaken the polarization, increase particle contacts and reduce the resistance, which improve the conductivity of the active substance and the discharge capacity of the battery and the utilization of active substance to a certain extent, but do not contribute to battery life. By the study of the grid corrosion product, We find that the addition of Sb2O3 change the grid structure of corrosion products, and generate a corrosion product, so that the active substance with the adhesion between the grid increased, keep the active substance in the course of the cycle off easy in favor of the integrity of the structure of the active substance.In front of the two types of additives on the basis of the study, further study of SnO2 and Sb2O3 as a composite additives for lead-acid battery performance. The results show that the positive active material to add 0.3% SnO2 and 3% Sb2O3, increased battery capacity.