Insoluble low-impedance organic battery cathode enabled by graphite grafting towards potassium storage.

Organic electrode materials are extensively applied for potassium storage as their sustainability and low cost. However, the organic electrodes' (i) solubility (such as naphthalene-1,4,5,8-tetracarboxylic dianhydride, NTCDA; 2,6-diaminoanthanthraquinone, DAQ, which are easily soluble in organic solvents) and (ii) intrinsic poor conductivity often result in high impedance and inferior electrochemical performance. Herein, the monomers of NTCDA and DAQ were polymerized (PND) to obtain an insoluble organic cathode, and a 5 wt% graphite (G) was also used to graft the PND sheet and increase its conductivity. Consequently, the as-prepared organic cathode (PND-G) achieved a long-life cycling performance of over 1500 cycles at 100 mA g. This work may provide guidelines for designing and developing insoluble and high conductive organic electrode materials.