Intercalation and covalent bonding strategies for constructing a stable cathode for high-energy density and long-cycling potassium-organic batteries

Cost-efficient, potassium–organic batteries with high stability are a high-profile technology for grid-scale energy storage. However, their development has been limited by the lack of stable cathode materials, which must be cost-effective without compromising performance. Here we present a commercially available organic cathode (BR-rGO) constructed by utilizing covalent bonding and intercalation strategies toward high energy density potassium storage. In our design, covalent bonds between BR and rGO effectively stabilize the structure of the electrode, thereby limiting the dissolution of organic materials in the electrolyte. Furthermore, intercalation of organic molecules into rGO layers provides more accessible active sites and K+/electron diffusion channels, leading to enhanced reaction kinetics. The resulting cathode delivered an excellent specific capacity of 127 mAh g−1 after 150 cycles at 0.2 A g−1 and superior rate capability. Upon incorporating the BR-rGO cathode into a full battery with a porous carbon anode, the cathode exhibited a high energy density of 168 Wh kg−1 and a superior cycle stability over 3000 cycles. Attaining high energy density using commercially available components is an achievement that represents an essential step towards practical potassium-ion full batteries.