Laser-Induced Graphite as a Charge Storage Host for Reversible Intercalation of Potassium Ions

Abstract

Conventional graphite is known to intercalate potassium ions in a reversible manner; however, thick and unstable solid electrolyte interphase (SEI) formation impedes the transportation of potassium ions. In this work, we report on the deployment of laser-induced graphitic carbon as an anode material for electrochemical intercalation of potassium ions. Despite an initial low coulombic efficiency, stable SEI formation on the laser-induced graphite electrode shows a reversible and stable potassiation capacity of 263 mAh/g at a specific current density of 25 mA/g, with 84% capacity retention over 150 cycles. The morphology of laser-induced graphite (LIG) probably promotes the controlled growth of interphase, unlike the case of conventional restacked graphite electrodes. Distribution of relaxation times (DRT) analysis confirms the facile diffusion of K⁺ ions through the SEI layer formed on LIG electrodes.