Nanoscale Electrical Degradation of Silicon-Carbon Composite Anode Materials for Lithium-Ion Batteries

Abstract: The high performance of lithium-ion batteries (LIBs) is in increasing demand for a variety of applications in rapidly growing energy-related fields, including electric vehicles. To develop high-performance LIBs, it is necessary to thoroughly understand the degradation mechanism of LIB electrodes. From this viewpoint, it is crucial to investigate how the electrical properties of LIB electrodes change under charging/discharging. Here, we probe the local electrical properties of LIB electrodes with nanoscale resolution via scanning spreading resistance microscopy (SSRM). Via quantitative and comparative SSRM measurements of pristine and degraded LIB anodes of blended Si-C composites with graphite (Gr) particles, the electrical degradation of the LIB anodes is visualized. The electrical conductivity of the Si-C composite particles is considerably degraded by 300 cycles of charging and discharging, although the Gr particles maintain their conductivity.