Shalini Rodrigues

A Review of state-of-charge indication of batteries by means of a.c. impedance measurements

A non-destructive estimation of the state-of-charge (SoC) of batteries facilitates optimum utilization of the battery for a given application, as well as evaluation of its state-of-health. Among various methods, a.c. impedance spectroscopy over a wide range of frequencies provides a variety of parameters which are functions of the SoC of a given battery. These parameters and their variation with SoC depend on the type of battery and on the experimental conditions. The impedance data of sealed commercial cells are rather tedious to analyze since the results are generally the combined parameters of both the positive and the negative electrodes. Separation of the parameters which correspond to the individual electrodes involves assumptions, the validity of which is open to question. Nevertheless, systematic linear and reproducible variations of measurable or computable impedance parameters with battery condition are useful indicators of the SoC in a non-destructive way. The present review consolidates the literature on the prediction of the SoC of batteries by means of a.c. impedance measurements.

A cyclic voltammetric study of the kinetics and mechanism of electrodeposition of manganese dioxide

The kinetics and mechanism of electrooxidation of Mn2+ ions to MnO2 (EMD) has been studied in electrolytes comprising MnSO4 and H2SO4 by cyclic voltammetry at 80°C. The voltammogram of a Pt electrode cycled between 0.6 and 1.6V vs SCE exhibits an anodic current peak at about 1.3V vs SCE resulting in the deposition of MnO2 on the electrode, while a cathodic peak appears at 0.8V vs SCE. It is shown that the pair of peaks do not correspond to a single reversible reaction but represent two separate irreversible electrode processes. The cyclic voltammetric peak current for the deposition of EMD is found to be proportional to the square root of Mn2+ ion concentration in the electrolyte and independent of acid concentration. Based on these results, a mechanism for the formation of EMD involving diffusion of Mn2+ ions to the electrode surface, oxidation of Mn2+surface to Mn3+ads, and H2O to OHads as the primary oxidation steps is invoked. Mn3+ads ions dissociate disproportionately into Mn2+ads and Mn4+ads ions at the electrode surface. The Mn2+ads and Mn4+ads ions, respectively, react with OHads and H2O resulting in the formation of EMD.

Novel solution-combustion synthesis of LiCoO2 and its characterization as cathode material for lithium-ion cells

Lithium cobalt oxide

Effect of lightweight supports on specific discharge capacity of β-nickel hydroxide

(LiCoO_2)

Synthesis of LiCo1-xNixO2 from a low temperature solution combustion route and characterization

which is being widely used as cathode material in lithium-ion batteries is synthesized by a novel solution-combustion procedure. In this synthesis, a solution mixture of

AC impedance and state-of-charge analysis of alkaline zinc/manganese dioxide primary cells

Co(NO_3)_2, Li_2CO_3

Kinetics of hydrogen evolution reaction on Zr0.5Ti0.5V0.6Cr0.2Ni1.2 alloy in KOH electrolyte

and diformyl hydrazine fuel is heated to ignite at

Effect of morphology on the performance of metal-hydride electrodes

350^o\hspace{2mm}C}

Fabrication and evaluation of 1 Ah silver/metal hydride cells

. This is accompanied by decomposition of cobalt nitrate and lithium carbonate to form

AC impedance behaviour and state-of-charge dependence of Zr0¨5Ti0¨5V0¨6Cr0¨2Ni1¨2 metal-hydride electrodes

LiCoO_2