Relaxation of Stress Propagation in Alloying‐Type Sn Anodes for K‐Ion Batteries
Hyokyeong Kang, Hyuk Kang, JunJi Piao, Xieyu Xu, Yangyang Liu, Shizhao Xiong, Seunggyeong Lee, Hun Kim, Hun‐Gi Jung, Jaekook Kim, Yang‐Kook Sun, Jang‐Yeon Hwang
Abstract
Abstract Alloying‐type metallic tin is perceived as a potential anode material for K‐ion batteries owing to its high theoretical capacity and reasonable working potential. However, pure Sn still face intractable issues of inferior K + storage capability owing to the mechanical degradation of electrode against large volume changes and formation of intermediary insulating phases K 4 Sn 9 and KSn during alloying reaction. Herein, the TiC/C–carbon nanotubes (CNTs) is prepared as an effective buffer matrix and composited with Sn particles (Sn–TiC/C–CNTs) through the high‐energy ball‐milling method. Owing to the conductive and rigid properties, the TiC/C–CNTs matrix enhances the electrical conductivity as well as mechanical integrity of Sn in the composite material and thus ultimately contributes to performance supremacy in terms of electrochemical K + storage properties. During potassiation process, the TiC/C–CNTs matrix not only dissipates the internal stress toward random radial orientations within the Sn particle but also provides electrical pathways for the intermediate insulating phases; this tends to reduce microcracking and prevent considerable electrode degradation.