Integrated conductive hybrid electrode materials based on ppy@zif-67-derived oxyhydroxide@cfs composites for energy storage

Abstract

Due to excellent flexibility and hydrophilicity, cellulose fibers (CFs) have become one of the most potential substrate materials in flexible and wearable electronics. In previous work, we prepared cobalt oxyhydroxide with crystal defects modified polypyrrole (PPy)@CFs composites with good electrochemical performance. In this work, we redesigned the crystalline and nanoscale cobalt oxyhydroxide with zeolitic imidazolate frameworks-67 (ZIF-67) as precursor. The results showed that the PPy@ZIF-67 derived cobalt oxyhydroxide@CFs (PZCC) hybrid electrode materials possess far better capacitance of 696.65 F·g−1 than those of PPy@CFs (308.75 F·g−1) and previous PPy@cobalt oxyhydroxide@CFs (571.3 F·g−1) at a current density of 0.2 A·g−1. The PZCC delivers an excellent cyclic stability (capacitance retention of 92.56%). Moreover, the PZCC-supercapacitors (SCs) can provide an energy density of 45.51 mWh cm−3 at a power density of 174.67 mWh·cm−3, suggesting the potential application in energy storage area.