Electrodeposition of Pb and PbO2 on Graphite Felt in Membraneless Flow-Through Reactor: A Method to Prepare Lightweight Electrode Grids for Lead-Acid Batteries

One of the possible ways of mitigating the primary lead-acid battery downside—mass— is to replace the heavy lead grids that can add up to half of the total electrode’s mass. The grids can be exchanged for a lightweight, chemically inert, and conductive material such as graphite felt. To reduce carbon surface area, Pb/PbO2 can be electrochemically deposited on graphite felt. A flow-through reactor was applied to enhance penetration of adequate coverage of graphite felt fibers. Three types of electrolytes (acetate, nitrate, and methanesulfonate) and two additives (ligninsulfonate and Triton X-100) were tested. The prepared composite electrodes showed greater mechanical strength, up to 5 times lower electrical resistivity, and acted as Pb and PbO2 electrodes in sulfuric acid electrolytes.

Enhancement of the Activity of Electrochemical Oxidation of BPS by Nd-Doped PbO2 Electrodes: Performance and Mechanism

The electrochemical oxidation processes have attracted tremendous attention on the destruction of toxic and non-biodegradable organics. A series of neodymium (Nd)-doped PbO2 electrodes (Ti/PbO2-Nd) were synthesized through a pulse electrodeposition method, and its activity of bisphenol S (BPS) removal was further examined. The morphologies and structures were characterized by the X-ray diffraction (XRD), scanning electron microscopy (SEM) and an energy dispersive spectrometer (EDS). The performance, energy consumption and mechanism of electrochemical oxidation of BPS by Ti/PbO2-Nd electrode were also discussed. Compared to the traditional Ti/PbO2 electrode, the Ti/PbO2-Nd enables finer crystal particles, facilitating the oxygen evolution overpotential (OEP) from 1.41V to 1.55V and the generation of hydroxyl radicals (•OH). Moreover, lower duty cycles during the preparation of the electrode also contribute to the tapering size of crystals. The results show that the Ti/PbO2-Nd electrode exhibits relatively high activity in the anodic oxidation of BPS. Over 95% of BPS could be removed with the current density of 15 mA cm−2. Moreover, the energy consumption of BPS degradation on Ti/PbO2-Nd electrode is 60.26 kWh m−3, much lower than that on Ti/PbO2 electrode (95.45 kWh m−3). To conclude, the Ti/PbO2-Nd electrode has been proven to be a promising material for BPS removal.

A Novel Porous Ni, Ce-Doped PbO2 Electrode for Efficient Treatment of Chloride Ion in Wastewater

The porous Ti/Sb-SnO2/Ni-Ce-PbO2 electrode was prepared by using a porous Ti plate as a substrate, an Sb-doped SnO2 as an intermediate, and a PbO2 doped with Ni and Ce as an active layer. The surface morphology and crystal structure of the electrode were characterized by scanning electron microscope(SEM), energy dispersive spectrometer(EDS), and X-Ray diffraction(XRD). The electrochemical performance of the electrodes was tested by linear sweep voltammetry (LSV), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and electrode life test. The results show that the novel porous Ni-Ce-PbO2 electrodes with larger active surface area have better electrochemical activity and longer electrode life than porous undoped PbO2 electrodes and flat Ni-Ce-PbO2 electrodes. In this work, the removal of Cl− in simulated wastewater on three electrodes was also studied. The results show that the removal effect of the porous Ni-Ce-PbO2 electrode is obviously better than the other two electrodes, and the removal rate is 87.4%, while the removal rates of the other two electrodes were 72.90% and 80.20%, respectively. In addition, the mechanism of electrochemical dechlorinating was also studied. With the progress of electrolysis, we find that the increase of OH- inhibits the degradation of Cl−, however, the porous Ni-Ce-PbO2 electrode can effectively improve the removal of Cl−.