Thorn-like and dendrite lead sulfate as negative electrode materials for enhancing the cycle performance of lead-acid batteries

During deep charge-discharge cycling of lead-acid batteries, the compact PbSO 4 layer on the negative electrode surface blocks the ion transport channels, limiting the mass transfer process. In this study, to enhance the electrochemical characteristics of lead-acid batteries, thorn-like and dendrite PbSO 4 with a high aspect ratio were prepared and used as negative electrode material. During the formation process, thorn-like and dendrite PbSO 4 increased the pore diameter and the total pore volume of the negative electrode. For the charge-discharge process, this provided enhanced ion transport channels, which improved the utilization rate of the negative active material (NAM) and rate performance of batteries. Under a current density of 100 mA g −1 and 100% depth of discharge (DOD), the specific discharge capacity of thorn-like and dendrite PbSO 4 batteries reached 110 mAh g −1 , and the batteries still maintained >70% of the maximum specific capacity after 1200 cycles. When the capacity decayed to 80% of the maximum specific capacity, the cycle life of thorn-like and dendrite PbSO 4 batteries was 64% higher than that of the nearly spherical PbSO 4 batteries. Owing to the thorn-like and dendrite PbSO 4 significantly changing the pore structure of the electrode and enhancing the mass transfer process, the irreversible sulfation of the negative electrode was inhibited, and the cycle life of the lead-acid battery effectively extended.