Phase boundary propagation in large LiFePO4 single crystals on delithiation.

Large single crystals of LiFePO(4) have been chemically delithiated. The relevance of chemical oxidation in comparison with electrochemical delithiation is discussed. Analyses of the Li content and profiles were done by electron energy loss spectroscopy and secondary ion mass spectrometry.

Stabilizers of Particle Size and Morphology: a Road Towards High-Rate Performance Insertion Materials.

It is demonstrated that using a very small amount of ceramic surface stabilizers (not forming coatings) can prevent particle growth and completely preserve their morphology during heating. For the example of titania, a supreme lithium insertion-rate performance is exhibited by such stabilized samples.

Generalized equivalent circuits for mixed conductors: silver sulfide as a model system.

Abstract: The generalized equivalent circuit for Hebb-Wagner polarization in the frequency domain proposed by Jamnik and Maier (J Electrochem Soc 146:4183, 1999) includes the space-charge polarization that was previously neglected. In the present work, using a self-coded Fortran program, the completely generalized equivalent circuit is successfully applied to a mixed conducting silver sulfide with an AgI electrode that suppresses the electronic flow. A whole set of fit parameters, such as geometric capacitance, partial conductivities, chemical capacitance or diffusivity, and the blocking and shunting characteristics of electrodes are independently but self-consistently obtained over a range of silver activities, as controlled by a galvanic cell.

Electrochemical kinetics of porous, carbon-decorated LiFePO4 cathodes: separation of wiring effects from solid state diffusion.

We try to identify the rate-determining step of electrochemical kinetics of a LiFePO(4)-carbon composite electrode by varying the mass of electrode and, additionally, by varying the charge-discharge current in a wide range. It is shown that the reversible capacity is almost independent of electrode mass at currents lower than ca. 1 C (170 mAh g(-1)).