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

Abstract

© The Author(s) 2018. Published by ECS. 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 (K2NDC), 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, K2NDC 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. K2NDC 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.