High gravimetric energy density lead acid battery with titanium-based negative grids employing expanded mesh sandwich structure

Abstract

Addressing the low gravimetric energy density issue caused by the heavy grid mass and poor active material utilization, a titanium-based, sandwich-structured expanded mesh grid (Ti/Cu/Pb) for lead-acid battery negative electrode is introduced. Titanium was chosen for its advantageous properties such as low density, high mechanical strength, and good electrical conductivity, which reduces the electrode mass and enhances battery gravimetric energy density. However, titanium's use in battery negative grids is limited due to its passivation in sulfuric acid and poor adhesion to the active material. To overcome these drawbacks, a copper layer is added to prevent passivation, and a lead layer is applied to improve the adhesion between the titanium matrix and the active material. This innovative Ti/Cu/Pb negative grid reduces electrode mass and increases current density, boosting active material utilization. Electrode with Ti/Cu/Pb negative grid achieves an gravimetric energy density of up to 163.5 Wh/kg, a 26 % increase over conventional lead-alloy electrode. With Ti/Cu/Pb negative grid, battery cycle life extends to 339 cycles under a 0.5C 100 % depth of discharge, marking a significant advance over existing lightweight negative grid batteries. This research not only demonstrates a significant step in lead-acid battery enhancement but also proposes a methodological approach for future high gravimetric energy density battery design.