Determination of the Kinetic Parameters of Mixed‐Conducting Electrodes and Application to the System Li3Sb

Abstract

An electrochemical galvanostatic intermittent titration technique (GITT) is described which combines both transient and steady‐state measurements to obtain kinetic properties of solid mixed‐conducting electrodes, as well as thermodynamic data. The derivation of quantities such as the chemical and component diffusion coefficients, the partial conductivity, the mobility, the thermodynamic enhancement factor, and the parabolic rate constant as a function of stoichiometry is presented. A description of the factors governing the equilibration of composition gradients in such phases is included. The technique is applied to the determination of the kinetic parameters of the compound “Li3normalSb,” which has a narrow composition range. For Li2.9994normalSb the chemical diffusion coefficient is 2×10−5 cm2 sec−1 at 360°C. This value is quite high, due to a large thermodynamic enhancement factor of 1.3×104 . The lithium component diffusion coefficient is comparatively small at this composition, 1.5×10−9 cm2 sec−1 . The partial conductivity and electrical mobility of lithium are 1.5×10−4 Ω−1 cm−1 and 3×10−8 cm2 V−1 sec−1 , respectively, at the same stoichiometry and temperature. Because of the very large values of the chemical diffusion coefficient and the fact that 3 moles of lithium can react per mole of antimony, this system may be of interest for use in new types of secondary batteries.

Studies on the lithium ion diffusion coefficients of electrospun Nb2O5 nanostructures using galvanostatic intermittent titration and electrochemical impedance spectroscopy

“…More detailed analysis are available in our previous publication [4]. GITT is a useful and well adopted technique to calculate the Li-diffusion coefficients of intercalated/de-intercalated compounds [10,11]. In this technique, the cell voltage is perturbated by charging or discharging at a constant current.…”

Determination of solid phase chemical diffusion coefficient and density of states by electrochemical methods: Application to iridium oxide-based thin films

“…Galvanostatic intermittent titration technique ͑GITT͒, potentiostatic intermittent titration technique ͑PITT͒, and electrochemical impedance spectroscopy ͑EIS͒ are frequently used methods to determine D of guest species in various inorganic hosts. [8][9][10] Recent advances regarding the analysis of these methods include correction for non-negligible charge transfer and Ohmic resistances in the PITT case 11 and introduction of anomalous diffusion when analyzing EIS data. 12 In chronopotentiometry ͑CP͒ and GITT experiments the quasi-steady-state potential is measured as ions are intercalated into the material.…”

Dynamic piezoresponse force microscopy: Spatially resolved probing of polarization dynamics in time and voltage domains

“…42,44,90 The latter can represent the polarization dynamics in ferroelectric capacitors, domain dynamics in tip-electrode experiments, oxygen vacancy or ionic diffusion in solid-state ionic materials, etc. Correspondingly, the data can be mapped on the appropriate physical models-for example, for solid state ionics these measurements offer a spatially resolved analog of the potentiostatic intermittent titration (PITT) 91,92 performed during charge-discharge measurements. However, in most cases, such models are unavailable or need to be adapted to SPM geometry, necessitating development of statistical or phenomenological analysis tools, as discussed below.…”