The influence of the characteristics of rice husk-based activated carbon on the performance of lead-carbon batteries and its potential mechanisms

Abstract

We explore the effects of rice husk-based activated carbon (RHAC) with different pore structure and functional groups on the performance of lead-carbon batteries (LCB) in high-rate partial state of charge (HRPSoC) and its potential mechanisms. The results show that the performance of negative electrode is mainly affected by the rate and efficiency of RHAC on electrocatalytic of lead deposition. Notably, the reaction of phosphoric acid with silica in rice husk can significantly increase the content of phosphorus functional groups, which can enhance the electrocatalytic rate by complexing lead ions and inhibit hydrogen evolution reaction (HER). Micropore is more prone to hydrogen evolution in the medium-to-high polarization region (-1.25V∼-1.5 V vs Hg/Hg2SO4) and hinder lead ion mass transfer, which leads to the general cycle performance of LCB containing high microporosity RHAC. In addition, RHAC only has a certain electric double layer capacitance (EDLC) contribution at the end of cycle, which is still on the premise that RHAC has high specific surface area (SSA) and mesoporosity.