Constructing flexible and conductive carbon matrix on organic potassium terephthalate to enhance the K-storage performance

Abstract

• A flexible and conductive carbon matrix was coated on organic K 2 TP and reduced graphene oxide composite. • The as-synthesized K 2 TP/rGO/C composite displays impressive cycle stability with a reversible specific capacity of 86 mAh g −1 at 200 mA g −1 over 500 cycles. • The improved K-storage mechanism of K 2 TP/rGO/C composite was systematically investigated. Organic potassium terephthalate (K 2 TP) shows promising applications as an anode material in potassium-ion (K-ion) batteries with flexible crystal structure, suitable work potential, stable capability in organic electrolyte and environmentally friendly. Nevertheless, the inherent poor electronic conductivity has been the bottleneck to construct high-performance organic K-ion batteries. Herein, we initially report a flexible and conductive carbon coating layer on organic K 2 TP and reduced graphene oxide composite via electrospinning methodology and controlling medium–low temperature heat treatment (denoted as K 2 TP/rGO/C). The as-synthesized K 2 TP/rGO/C composite displays impressive cycle stability with a reversible specific capacity of 86 mAh g −1 at 200 mA g −1 after 500 cycles with an average capacity decay rate of only 0.1 % per cycle. It is demonstrated that the flexible conductive carbon coating layer and the continuous conductive network structure can significantly improve the electronic conductivity of organic K 2 TP, and reduce the interface transfer resistance. The rational construction of organic composite can offer a guideline for high-performance organic K-ion batteries.