Solid State Ionics, Vol.331, 56-65, 2019
In situ strain measurements and stress analysis of SiO@C composite electrodes during electrochemical cycling by using digital image correlation
SiO@C layer/copper foil composite electrode specimens were prepared and characterized by energy dispersive spectroscopy and thermogravimetric analysis methods, respectively. The related cycling performances, cyclic voltammetry and electrochemical impedance spectroscopy of SiO@C composite electrodes were discussed. Full/local strain field features of SiO@C composite electrodes were in situ measured during electrochemical cycles by designing a special electrolytic cell and digital image correlation technique. The corresponding stress variation characterizations of SiO@C composite electrode under different cycles were obtained by using a mechanical chemical constitutive equation. The results are useful for revealing the volume expansion behaviors of SiO@C anode and the corresponding mechanical-chemical failure mechanisms.
Keywords:Lithium-ion battery;SiO@C composite electrode;Digital image correlation;In situ strain measurement;Stress evolution