Characterization of lead (II)-containing activated carbon and its excellent performance of extending lead-acid battery cycle life for high-rate partial-state-of-charge operation

摘要

In this work, lead (II)-containing activated carbon (Pb@C) is prepared as the additive of negative active mass (NAM), alining to enhance the electrochemical characteristics of the lead-acid battery. The characters of the Pb@C materials and their electrochemical properties are characterized by XRD, SEM, backscattering electron image (BESI) and electrochemical methods. The lead (II) ions disperse well in the carbon bulk of the obtained Pb@C materials as observed, and these materials exhibit remarkable higher specific capacitance and higher hydrogen evolution over-potential compared with original carbons. Many 2 V lead-acid batteries are assembled manually in our lab, and then the batteries are disassembled after formation and high-rate-partial-state-of-charge (HRPSoC) cycling. Results manifest that the Pb@C additives exhibit high affinity to lead and act as a porous-skeleton in the formation process as well as under HRPSoC cycling conditions, leading to the small and fine formation of PbSO4 particles and accordingly higher active material utilization rate more than 50%, better cycling performance and charging acceptance. Besides, excellent cycle performances of these batteries have great relationship with the dazzling hydrogen evolution performance of Pb@C materials. A possible working mechanism is also proposed based on the testing data in this paper. (C) 2015 Elsevier B.V. All rights reserved.