Novel polymer-graphite composite grid as a negative current collector for lead-acid batteries

We design a novel polymer-graphite composite grid as the negative current collector for lead-acid batteries. With this novel grid, the negative active material (NAM) can deliver a specific capacity of 170 mAh g−1 at a discharge rate of 0.1 C. After that, we conduct structural optimization and surface treatment on the grid to improve its performance. Through the structural optimization, additional lead pastes can be loaded and the cycle stability of the battery is enhanced. By using the optimized grid, the weight of the negative current collector can be remarkably reduced by more than 50%. To handle the serious hydrogen evolution on the graphite surface and the unfavorable adhesion between graphite and NAM, fine PbSO4 particles are coated onto the surface of the graphite grids by chemical deposition. The cells employing the PbSO4-deposition grids exhibit excellent cycling stability as well as low polarization and then high Coulombic efficiency. We present here a possible mechanism that how PbSO4 deposits effectively enhance the performance of negative plates based on the testing results.