Impedance Inhomogeneity in SiO/Gr Composite Anode

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• Silicon/carbon (Si/C) composites are promising for high-energy-density lithium-ion batteries (LIBs).
• Si-based anodes face challenges due to significant volume changes and electrochemical-mechanical coupling, leading to impedance inhomogeneity.
• This inhomogeneity negatively impacts the discharging capacity of Si-based LIBs.

Purpose of the Study:

• To comprehensively understand the mechanisms behind impedance inhomogeneity in Si/C composite anodes.
• To investigate the evolution of polarization components during battery cycling.
• To provide insights for designing advanced anodes for next-generation LIBs.

Main Methods:

• Development of an electrochemo-mechanical-coupled model incorporating detailed anode particle geometries.
• Systematic investigation of polarization components and their evolution during charging/discharging.
• Analysis of influencing factors like SiO content, electrode thickness, and SiO distribution.

Main Results:

• The study elucidates the mechanisms of impedance inhomogeneity in Si/C composite anodes.
• It quantifies the evolution of polarization components under various conditions.
• An efficient computational approach is presented for analyzing battery polarizations.

Conclusions:

• Understanding electrochemo-mechanical coupling is crucial for Si/C anode performance.
• The developed model provides a tool to predict and mitigate impedance inhomogeneity.
• Insights gained can guide the rational design of high-performance anodes for future LIBs.