Topological Defect-Regulated Porous Carbon Nanoribbon for High-Performance Potassium-Ion Batteries.

Potassium-ion batteries (PIBs) using carbonaceous anode materials have attracted a great deal of research interest. However, the large atomic size of potassium ions inevitably leads to huge volume expansion and the collapse of anodes during intercalation, which greatly hinders rate performance and cycling life. In this work, carbon nanotube-derived porous N-doped carbon nanoribbon (CNR) bundles are designed as an anode for PIBs. These CNR materials are in rich defects which provide fast channels for charge transport and abundant active sites for potassium ion storage. The CNR materials exhibit a maximum capacity of 441.4 mA h g at a current density of 0.2 A g after 200 cycles as well as a highly reversible capacity of 263.6 mA h g at a current density of 5.0 A g even after 1000 cycles. This work provides guidance for the structure design of nanoribbon materials for high-performance PIBs.