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

Abstract

Mechanical stress was applied to the specimen by four points bending tests while measuring electromotive force (EMF) between the two electrodes. EMF proportional to the applied stress was observed. EMF was significantly dependent on the electrode material, but was almost independent of the electrolyte material. These results indicated that lithium chemical potential varied under mechanical stress both in the electrode and electrolyte but the influence of mechanical stress appeared more notably in the electrode than the electrolyte. The lithium chemical potential changes in the electrode and the electrolyte under mechanical stress were discussed based on the idea of local equilibrium.

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.…”

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

“…However, at this moment, we think that the contribution toEMF from the electrolyte is much smaller compared with that from the electrode. In fact, the dependence of EMF on the mechanical stress was closely similarwith the differentsolid electrolyte and thesame electrode materials, while it was obviously different with the samesolid electrolyte and the different electrode materials.Detailed discussion together with experimental results will appear in a separated paper [12].…”

Experimental Evaluation of Influence of Stress on Li Chemical Potential and Phase Equilibrium in Two-phase Battery Electrode Materials

“…3,5,7,10,[13][14][15] Furthermore, in recent years, stress is being recognized to significantly affect the material properties of the battery electrode and electrolyte materials such as ionic transport, 16,17 defect concentration, 18 electrochemical reaction, 19,20 phase separation, 21,22 and electrode potential. [23][24][25][26][27][28] Therefore, fundamental understandings of the influence of stress on material properties of the battery electrode and electrolyte materials are essential in enhancing the performance and stability of SSBs. To this end, we have developed an experimental technique that can quantify the influence of stress on the Li chemical potential (µLi) in a battery electrode material.…”