Huang T.,Fuzhou University |
Ou W.,Fuzhou University |
Feng B.,Fuzhou University |
Huang B.,Fuzhou University |
And 3 more authors.
Journal of Power Sources | Year: 2012
A cell with tall plates was simulated by two cells and the controlled voltage with time was successfully used to measure the response current-time curves. It indicates that the current in the upper part of the plate is much higher than that in the lower part in early stage of the discharge, but in late stage, it is reversed, especially at high discharge rates. The upper part of the plate has higher capacity and deeper depth of discharge (DOD) so that the active mass degrades and sheds more quickly in cyclic applications. In the initial discharge, the lead sulfate formed at positive plates produces the internal stress and enhances the electric connection among the active mass particles. But the positive active mass only contributes a little to the conductivity of plates. The negative active mass with a bit shrinking but no passivation has better conductivity than the expanded active mass. The higher ohmic polarization of the active mass appears at higher discharge rates, in the upper part of the plates, in the late stage of the discharge, in aged battery, especially for negative plates. © 2012 Elsevier B.V. All rights reserved. Source
Sun X.,Fuzhou University |
Zhao J.,Fuzhou University |
Chen T.,Chaowei Power Co. |
Liu X.,Chaowei Power Co.
Journal of Solid State Electrochemistry | Year: 2015
Commercial-grade fumed silica was dispersed by mechanical shearing and/or ultrasonic force to produce dispersed silica particles with different sizes. The light-scattering technique and a diagrammatic method of extrapolation used to eliminate the influence of particle interaction were applied to determine the size of the particles. Then, the effect of particle size on the gelation of fumed silica in sulphuric acid medium, as well as some electrochemical properties, such as ion transfer and redox capacities of lead, in the gelled electrolyte were examined. The results showed that the size of dispersed particles affected the gelation of fumed silica itself: with increasing size, the thixotropy of the system increased and the gelling time decreased, particularly for those particles obtained only by simple stirring. The strength of the gel increased with increasing particle size. At an identical silica content, the increase in particle size led to a decrease in the density of the particles: this weakened the three-dimensional structure of the silica particle network and reduced the efficiency of ion transfer. However, the effect of silica particle size on the redox capacities of lead was negligible. © 2015 Springer-Verlag Berlin Heidelberg Source
Lv Y.-Z.,Harbin Engineering University |
Tang D.-D.,Harbin Engineering University |
Xu D.,Chaowei Power Co. |
Jin Y.-Z.,Harbin Engineering University |
And 7 more authors.
RSC Advances | Year: 2014
The electrochemical performance of Mg-8Li-0.5Zn electrode in 0.7 mol L-1 NaCl solution with different concentrations of NaF (0.0, 0.2, 0.5, 0.8, 1.0, 1.2 and 1.5 mmol L-1) was investigated by means of potentiodynamic polarization, potentiostatic current-time curves, electrochemical impedance spectroscopy, scanning electron microscopy and utilization efficiencies. The findings indicate that Mg-8Li-0.5Zn electrode in 0.7 mol L-1 NaCl solution with 1.0 mmol L-1 NaF has a higher discharge current density than that in 0.7 mol L-1 NaCl solution with the other concentrations of NaF that were investigated. The addition of 1.0 mmol L-1 NaF to the NaCl electrolyte solution loosens the product film and the oxidation products on the alloy surfaces of the electrode, which produces deeper and larger channels, as observed by the SEM investigation, compared with those in 0.7 mol L-1 NaCl solution without any NaF. The addition of 1.0 mmol L-1 NaF in 0.7 mol L-1 NaCl solution improves the continuous discharging utilization efficiency of Mg-8Li-0.5Zn electrode by more than 18.80%, and enhances the interval discharge utilization efficiency of Mg-8Li-0.5Zn electrode by more than 27.90%. © 2014 The Royal Society of Chemistry. Source
Chaowei Power Co. | Date: 2015-08-12
Batteries, electric, for vehicles; accumulators, electric, for vehicles; battery boxes; plates for batteries; batteries for lighting; battery chargers; batteries, electric; accumulators, electric; photovoltaic cells; solar batteries.