Electrochemical intercalation mechanism

Although electrochemical characterizations have recently been performed on single intercalation particles, in most cases composite powdery electrodes containing a mixture of intercalation particles, electrically conductive additives (e.g., carbon black) and PVDF binder have also been used. In order to obtain consistent results and to reach comprehensible intercalation mechanisms in these electrodes, basic electroanalytical characterizations such as slow-scan rate -> cyclic voltammetry (SSCV), -> potentiostatic intermittent titration (PITT) (or -> galvanostatic intermittent titration, GITT), and -> electrochemical impedance spectroscopy (EIS) should be applied in parallel or in a single study. 

In this ideal scheme, the electrode is a surface without any capacity. The electrical capacity would be observed only if the surface electrode is expanded in volume, by interposing a material possessing the three properties of the junction (1) an electronic conductivity (e ), (2) an ionic conductivity (A or B ) and (3) a chemical potential (//a or imposed. As a consequence, the electrode material must have a host lattice stmcture, H) and participates to the electrochemical reaction via an intercalation mechanism (Fig. 3.1)... 

Bohnke O, Bohnke C, Fourquet JL (1996) Mechanism of ionic conduction and electrochemical intercalation of Uthium into the perovskite lanthanum lithium titanate. Solid State Ionics 91(1-2) 21-31,http //dx.doi.org/10.1016/S0167-2738(96)00434-l... 

Apart from the work toward practical lithium batteries, two new areas of theoretical electrochemistry research were initiated in this context. The first is the mechanism of passivation of highly active metals (such as lithium) in solutions involving organic solvents and strong inorganic oxidizers (such as thionyl chloride). The creation of lithium power sources has only been possible because of the specific character of lithium passivation. The second area is the thermodynamics, mechanism, and kinetics of electrochemical incorporation (intercalation and deintercalation) of various ions into matrix structures of various solid compounds. In most lithium power sources, such processes occur at the positive electrode, but in some of them they occur at the negative electrode as well. 

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