Industrial Validation of Lead-plated Aluminum Negative Grid for Lead-acid Batteries

Aluminum metal grids as lightweight substitutes for lead grid are promising to achieve the overall weight reduction of lead-acid battery for increasing energy density without sacrificing charge/discharge and cyclic performance. In this paper, a dense lead layer with an average thickness of 40 mu m is industrially electro-deposited onto aluminum grid with a pre-plated nickel interlayer as the negative electrode for lead-acid battery. The charge/discharge tests with such an grid as negative plates show that the false welding between the lead-plated aluminum grid and lead busbar is an important challenge due to the thin plated lead layer, which would be a potential long-term risk for the charge step and sulfation. From dissection of the failed battery, it is found that the dense lead layer is partially corroded by sulfuric acid and aluminum substrate is partially dissolved into the electrolyte. Sulfation at such a negative electrode brings about a dense and sticky layer composed of the mixed PbSO4 and Al-2(SO4)(3)center dot 18H(2)O, which is the main failure mode of the lead-acid battery. This industial validation demonstrates that lead-deposited aluminum grids are not feasible at negative electrodes of light-weight lead-acid batteries from the viewpoint of commmercial reliability.