The lead-acid battery industry in my country has a history of more than a hundred years. Due to the characteristics of cheap materials, simple technology, mature technology, low self-discharge, and maintenance-free requirements, it will still dominate the market in the next few decades. In many application fields, the technological progress of lead-acid batteries has made a tangible contribution to improving national competitiveness. Calcium alloy has high hydrogen potential and strong corrosion resistance. It is used to make lead-acid battery grids, which can improve the efficiency of the negative electrode to the internal oxygen of the battery and increase the efficiency of the positive electrode in deep discharge cycles.
Application of Calcium Aluminum Alloy in Storage Battery
Lead-acid batteries have a history of nearly 160 years. Its mass specific energy and volume specific energy cannot be compared with Ni-Cd, Ni-MH, Li ion and Li polymer batteries. But because of its low price, good high-current discharge performance, and no memory effect, it can be made into a single large-capacity battery (4500Ah) and other excellent performance. Therefore, it is still widely used in automotive, telecommunications, electric power, UPS, railway, military and other fields, and its sales are still in the forefront of chemical power products.
How lead calcium alloy is widely used in battery industry
1. In order to reduce battery water decomposition and reduce battery maintenance work, Hanring and Thomas [50] invented a lead-calcium alloy in 1935, which was used to produce cast grids for stationary batteries used in communication centers.
2. The grid material commonly used in maintenance-free batteries is Pb-Ca alloy. According to the content, it is divided into high calcium, medium calcium and low calcium alloy.
3. The lead-calcium alloy is precipitation hardening, that is, Pb3Ca is formed in the lead matrix, and the intermetallic compound precipitates in the lead matrix to form a hardened network.
Grid is the most important inactive material in lead-acid batteries. Since the invention of lead-acid batteries, Pb-Sb alloy has been the most important material for grids. With the emergence of maintenance-free lead-acid batteries, Pb-Sb alloys have become Can not meet the maintenance-free performance requirements of batteries, and gradually replaced by other alloys.
Studies have found that Pb-Ca alloy has excellent maintenance-free performance, but its intergranular corrosion phenomenon is serious, and the calcium content is not easy to control, especially the high-impedance passivation film formed on the surface of the battery grid seriously hinders the battery charge and discharge process. , Make the battery's early capacity loss (PCL) phenomenon aggravated, thereby greatly shortening the battery's service life, of which the influence of the positive grid is the most. Adding a small amount of aluminum has the effect of protecting calcium. Research has found that tin can improve the performance of the passivation film and enhance the deep cycle performance of the battery.
