| Due to the requirement of environmental protection to the country,the positive grid Pb-Sb-Cd alloys of lead-acid battery are gradually replaced by the Pb-Ca alloys.But the positive grid Pb-Ca alloys appeared early corrosion phenomenon because the alloy composition was not reasonable.And the abnormal corrosion of Pb-Ca alloys is one of limiting factors in battery deep cycle.So improving positive grid Pb-Sb-Cd alloys corrosion resistance has important practical significance.This paper firstly optimizes Sn-Ca proportion in Pb-Ca-Sn-Al alloys.Then improving the positive grid Pb-Ca alloys corrosion resistance uses the method that adds new element Bi in the alloys.In the experiment that optimizes Sn-Ca proportion,four kinds of different Sn-Ca proportions of Pb-Ca-Sn-Al alloys firstly are prepared in the proportion of reasonable range.Then these alloys are tested by direct reading spectrometer,constant current corrosion experiment,microscopic analysis,hardness experiment,electrochemical method and using these alloys assemble the batteries to make battery performance test.Through these experiments get more optimized Sn-Ca proportion.These experiments get the conclusion that alloys corrosion resistance and battery performance are all more optimized when the content of Ca is 0.081% and the content of Sn is 1.220% and Sn-Ca proportion is 15.1.In the proportion of reasonable range,the higher Sn-Ca proportion,Pb-Ca alloys corrosion resistance is stronger.In the experiment that improves the positive grid Pb-Ca alloys corrosion resistance uses the method that adds Bi in the alloys.Using previous chapter experiments of conclusion that the content of Ca is 0.081% and the content of Sn is 1.220% as the basis of experimental compound alloys prepares a kind of Pb-Ca-Sn-Al alloy and three kinds of Pb-Ca-Sn-Al-Bi alloys with different content of Bi.Then these alloys are tested by direct reading spectrometer,constant current corrosion experiment,microscopic analysis,hardness experiment,electrochemical method and using these alloys assemble the batteries to make battery performance test.Through these experiments analysis the effect of adding Bi in the alloys.These experiments get the conclusion that adding Bi can make alloys oxygen evolution potential and resistance to reduce in small increments,but alloys corrosion resistance and battery performance to improve particularly.So adding Bi in the alloys canimprove the positive grid Pb-Ca alloys corrosion resistance.When the content of Bi is about0.075%,the effect is best.Lastly,all the experiments get the conclusion that positive grid Pb-Ca alloys corrosion resistance is more optimized when the content of Ca is about 0.081% and the content of Sn is about 1.220% and Sn-Ca proportion is about 15.1 and the content of Bi is about 0.075%. |
