Electrochemical Properties of Chitosan‐Modified PbO2 as Positive Electrode for Lead–Acid Batteries

The structure and properties of the positive active material PbO 2 are key factors affecting the performance of lead–acid batteries. To improve the cycle life and specific capacity of lead–acid batteries, a chitosan (CS)‐modified PbO 2 –CS–F cathode material is prepared by electrodeposition in a lead methanesulfonate system. The microstructure and phase composition are characterized by scanning electron microscopy and X‐ray diffraction. The electrochemical activity of the cathode material is analyzed by cyclic voltammetry, linear sweep voltammograms, electrochemical impedance spectroscopy, and scanning electrochemical microscopy. The battery performance of laboratory lead–acid batteries assembled with the cathode material is analyzed by a battery tester. The results show that the PbO 2 –CS–F cathode material has the smallest grain size (21.879 nm), the highest oxygen evolution potential (2.237 V), and the highest exchange current density (3.788 × 10 −7 A cm −2 ), smallest charge transfer resistance (5.359 Ω cm 2 ), and highest chemical activity in the series of PbO 2 cathode materials. The laboratory lead–acid battery assembled from PbO 2 –CS–F cathode material exhibist the best battery performance, with the first discharge capacities of 4257 mAh and the discharge‐specific capacity after 500 cycles is 196 mAh g −1 .