Porous polyimide framework based on perylene and triazine for reversible potassium-ion storage

Abstract

Potassium-ion batteries have attracted considerable attention as an emerging energy-storage solution due to the abundance of potassium resources. The current development of potassium-ion batteries is, however, largely impeded by the lack of high-capacity and cyclable electrode materials. Herein, we report that porous polyimide frameworks (PIFs) based on perylene and triazine are a promising anode material for potassium-ion batteries. Thanks to the high-density electroactive imide groups and their robust molecular structure, our PIF delivers a large reversible specific capacity of ∼190 mA h g⁻¹ at 0.2 A g⁻¹, a good rate performance (∼115 mA h g⁻¹ at 2 A g⁻¹) and long cycling stability (83% capacity retention after 1000 cycles at 5 A g⁻¹). These metrics render PIFs a highly promising anode material for potassium-ion batteries for future large-scale energy-storage applications.