Electromotive force measurements of LiCoO2 electrode on a lithium ion-conducting glass ceramics under mechanical stress

Abstract

Two LiCoO 2 dense film electrodes wereprepared on both surfaces of alithium ion conducting glass ceramics, and electromotive force measurements were preformed between the film electrodes under mechanical compressive and tensile stresses by four points bending tests. Electromotive force appeared immediatelyafter applying the stress, and disappeared after releasing the stress. The larger stress was applied, the largerelectromotive force was observed.These results clearly demonstrated that the lithium chemical potential in the © 2015. This manuscript version is made available under the Elsevier user license http://www.elsevier.com/open-access/userlicense/1.0/ 2 LiCoO 2 electrode varies under mechanical stress. The influence of the mechanical stress on the lithium chemical potential was discussed based on the relation between the CoO 2 interlayer distance and the lithium concentration in LiCoO 2 .

Experimental Studies on Work Functions of Li+ Ions and Electrons in the Battery Electrode Material LiCoO2: A Thermodynamic Cycle Combining Ionic and Electronic Structure

“…Considerable efforts today go in the direction of understanding the structure property relation of Lithium battery materials at the atomic level, e.g., the Li + ion diffusion has been studied in single nanocrystals of LiCoO 2 by optical means . Mechanical stress originating from structural changes may even influence the Lithium chemical potential …”

Persistent State‐of‐Charge Heterogeneity in Relaxed, Partially Charged Li1−xNi1/3Co1/3Mn1/3O2 Secondary Particles

“…The coupling of stress with lithium chemical potential has been demonstrated both theoretically and experimentally in LiCoO 2 , Si, and LiFePO 4 electrodes, as well as in the solid electrolyte interphase . Essentially, for any lattice whose volume is a function of lithium content, the lithium chemical potential and lattice strain are coupled.…”

Effect of Mechanical Stress on Lithium Chemical Potential in Positive Electrodes and Solid Electrolytes for Lithium Ion Batteries

“…A similar EMF behavior was observed with the symmetric cell of LCO/LICGC/ LCO in another work. 6 As already discussed in detail, 6 it is considered that such an EMF behavior accompanied with the mechanical load can be interpreted as the change in the lithium chemical potential in the constrained LCO electrodes due to the mechanical stress. As described in the experimental section, the LCO films in this work were oriented in the direction of [001], meaning the CoO 2 layers deposited alongside the electrolyte substrate.…”

“…2, EMF of the lower side electrode with reference to the upper electrode was measured by the digital multimeters (2182A, Keithley Instruments Inc., Japan) under four points bending tests with the mechanical load of 0-130 N. In this experimental setup, compressive and tensile stresses were given to the in-plane direction of the upper and the lower side electrodes, respectively. In this work, as we did in another work, 6 it was assumed that the influence of the stress on EMF is comparable for tensile and compressive stresses while giving the opposite sign. Based on this assumption, we introduce the "nominal" mechanical stress in the following discussion, which is the mechanical stress on the lower electrode (tensile side) with reference to that on the upper electrodes (compressive side).…”

“…In another study, 6 LiCoO 2 (LCO) dense film electrodes were prepared on both surfaces of the lithium ion conducting glass ceramics (LICGC), and electromotive force (EMF) measurements between two LCO electrodes were carried out while applying mechanical stress to the electrodes by four points bending tests. The generation of EMF was clearly observed with the application of mechanical stress.…”