Conductive atomic force microscopy (C-AFM) is widely used to determine the electronic conductivity of a sample surface with nanoscale spatial resolution. However, the origin of possible artifacts has not been widely researched, hindering the accurate and reliable interpretation of C-AFM imaging results. Herein, artifact-free C-AFM is used to observe the electron conduction channels in Si-based composite anodes. The origin of a typical C-AFM artifact induced by surface morphology is investigated using a relevant statistical method that enables visualization of the contribution of artifacts in each C-AFM image. The artifact is suppressed by polishing the sample surface using a cooling cross-section polisher, which is confirmed by Pearson correlation analysis. The artifact-free C-AFM image was used to compare the current signals (before and after cycling) from two different composite anodes comprising single-walled carbon nanotubes (SWCNTs) and carbon black as conductive additives. The relationship between the electrical degradation and morphological evolution of the active materials depending on the conductive additive is discussed to explain the improved electrical and electrochemical properties of the electrode containing SWCNTs.

Uncontrolled volume changes in Si-based anode materials drastically deteriorate the electron-conduction network, accelerating the capacity fading. From a macroscopic viewpoint, the use of single-walled carbon nanotubes (SWCNTs) as conductive additives has been confirmed to help preserve electron-conduction channels. However, the specific mechanism of how SWCNTs behave in Si-based anodes remains unclear. Herein, we investigate the role of SWCNTs in the pulverization behavior of Si-based anode materials at the nanoscale. Surface potential mapping using Kelvin probe force microscopy showed an uneven charging/discharging process of the Si-based anode in the absence of SWCNT additives. Conversely, the anode including SWCNTs enabled uniform electron transfer to the active material, providing a stable electrochemical reaction site. Our visualization method reveals the role of SWCNTs in ensuring uniform volume change during cycling and ultimately alleviation of particle pulverization.