Conjugated Dicarboxylate with Extended Naphthyl Skeleton as an Advanced Organic Anode for Potassium-Ion Battery

Organic compounds have attracted great attention as the promising electrode materials for potassium-ion batteries. Here, a conjugated dicarboxylate derivative, potassium naphthalene-2,6-dicarboxylate (K 2 NDC), based on aromatic naphthyl skeleton, is applied as advanced organic anode for K + storage and release efficiently. Since the dicarboxylate group is the electrochemically active site, K 2 NDC exhibits two-electron redox mechanism. Meanwhile, a relatively low redox potential of ∼0.55 V vs . K + /K is achieved, partly due to the extended conjugation structure of the naphthyl ligand. K 2 NDC delivers a high average specific capacity of 139 mAh g −1 at 100 mA g −1 with the capacity retention of 93% after 300 cycles.