ABSTRACT Covalent organic framework (COF) materials with molecule‐level functionality show great promise as anode materials for K‐ion batteries (KIBs). However, their practical application is hindered by limited capacity and poor cycling stability, especially under extreme temperatures. These issues stem from the large ionic size of K + and thermally induced electrochemical degradation. Herein, we present a COF nanotube with a conjugated periodic skeleton and a high density of redox‐active sites