Structure-Modified\nAnode Material for Regenerable\nOrganic Potassium-Ion Batteries

As the mismatch between the growing demand for energy\nstorage and\nthe scarcity of resources for the current lithium-ion batteries (LIBs)\nescalates, it is urgent to seek out an alternative solution for energy\nstorage devices. Potassium-ion batteries (PIBs), with their resource\nabundance and analogous electrochemical potential, are expected to\nbe a promising contender. Herein, by structure modification, a novel\norganic anode material of 2,5-bis(methoxycarbonyl)-3,6-dioxocyclohexa-1,4-dienolate\n(K<sub>2</sub>dmcdbq) is synthesized and composited with carbon nanotubes\nto realize the properties of high capacity, high rate, cycle retention,\nand regenerability. The unique cation storage and capacity degradation\nmechanisms of the PIBs are studied, and the electrochemical performance\nis thoroughly recovered by a chemical regeneration process. Combined\nwith the perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) cathode,\nthe environmentally friendly all-organic potassium full cells achieve\na regenerable energy density of 119 Wh kg<sup>–1</sup> and\na power density of 113 W kg<sup>–1</sup>, which provides a\nfresh sight of material design for electrochemically active organic\nmaterials.