posted on 2022-06-22, 18:39authored byGun Park, Youngwoo Choi, Sunyoung Shin, Yongju Lee, Seungbum Hong
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.