Towards renewable energy storage: Understanding the roles of rice husk-based hierarchical porous carbon in the negative electrode of lead-carbon battery

摘要

To prolong the cycle life of lead-carbon battery towards renewable energy storage, a challenging task is to maximize the positive effects of carbon additive used for lead-carbon electrode. In this paper, rice-husk-derived hierarchical porous carbon (RHHPC) is used to improve the electrochemical kinetics of lead-carbon electrode. Results show that charge acceptance of lead-carbon electrode is increased mainly due to the extra electrochemically active surface provided by RHHPC. Compared with the other carbon additives, RHHPC with high surface area and combined mesopores/macropores hierarchical structure exhibits a significant effect on the electrochemical kinetics of Pb/PbSO4 redox couple. Thus, the lead-carbon battery containing RHHPC shows good rate performance and excellent charge acceptance in deep charge/discharge partial state of charge operation. This study also suggests that carbon additive inevitably accelerates hydrogen evolution which breaks down the conductive network of lead-carbon electrode, so hydrogen evolution must be suppressed to enhance the cycling stability of lead-carbon battery.