Sustainably flexible and free-standing organic carbonyl potassium salt with continuous conductive network as high-performance anode in K-ion batteries

Developing suitable electrode materials with high flexibility, superior cyclic performance and low-cost have been the new topic and difficulty in the up-coming wearable flexible device. Herein, organic potassium terephthalate (K2TP) with MWCNTs and conductive polymer PEDOT:PSS co-coated K2TP/2MWCNTs/PP composite endowing continuous conductive network, was initially developed as a pliable and free-standing anode material for potassium ion batteries. By analyzing the internal microstructure, external topography and varies electrochemical characterization of the prepared samples, the incorporation of reasonable MWCNTs and PEDOT:PSS allows for the construction of a continuous conductive network with a large specific surface area, the creation of an effective electron transfer channel, an improvement in the kinetics of K+ diffusion and the maintenance of structural integrality. A preeminent specific capacity of 154.3 mAh g−1 can be maintained after 100 cycles at the current density of 50 mA g−1, prevailing over the majority of claimed anode materials employed in K-ion batteries. Furthermore, a high-performance all-organic full battery based on flexible anode and cathode material was successfully assembled delivering an extraordinary energy density of 320 Wh Kg−1. These results can put forward the practical application of organic electrode materials in systems for massive-scale energy storage. [Display omitted] •High-performance flexible and free-standing K2TP/2MWCNTs/PP anode was initially proposed in K-ion battery.•The K-storage mechanism of as-synthesized K2TP/2MWCNTs/PP was systemically investigated.•An all-organic full battery was successfully assembled with a high energy density of 320 Wh Kg−1.