The application of rice husk-based porous carbon in positive electrodes of lead acid batteries

Abstract

Abstract The positive electrodes of lead-acid batteries are typical thick electrodes where the mass transfer is limited. Therefore, the improvement of the mass transfer inside positive electrode can effectively enhance battery performance. In this article, the rice husk-based porous carbon (RHPC), is applied as an additive in positive electrodes of lead acid batteries. The addition of RHPC can increase the content of 3BS(3PbO·PbSO4·H2O) with decreased crystallinity and particle size in cured electrode. Next, it improves the formation efficiency. The electric conductivity and electron transfer rate of positive electrode are also enhanced. Under 100% DoD discharge condition, the discharge capacity of RHPC electrode increased by 16% and 23% at 0.05C and 1C, compared to that of blank electrode, respectively. Besides, the RHPC experimental cell displays higher discharge specific capacity compared to the blank experimental cell in a long-term deeply charge/discharge process. The developed pore structure of RHPC is beneficial to the curing process, while the developed pore structure and gas production of RHPC make major contributions to the formation and the deeply charge/discharge process. With RHPC additive in PAM, the improvement of the mass transfer can effectively reduces the risk of the failure mode for the mass transfer limit in such a typical thick electrode. Moreover, the particle growth rate of PAM will be inhibited during long-term deeply charge/discharge, thus the addition of RHPC will be very beneficial to increase the cyclic life of the positive electrode.