High-performance supercapacitor based on graphene oxide through in-situ polymerization and co-precipitation method

Abstract Herein, a novel laminate-like Co–Fe LDH/polypyrrole/graphene oxide (LPG) composite was firstly and successfully synthesized by a simple and effective co-precipitation process in which ultrathin CoFe-layer double hydroxides (LDH) nanosheets were electrostatically assembled on the surface of polypyrrole/graphene oxide (PG) substrate. The optimum LPG-2 electrode exhibits the highest specific capacity (638 C g−1 at 1 A g−1) and excellent cycle stability (85.55% after 4000 cycles). The reason for excellent electrochemical performance of LPG-2 electrode is ascribed to Co–Fe LDH with high conductivity and PG with high specific surface area. The LPG-2//AC ASC was assembled by LPG-2 material as the positive electrode, the activated carbon (AC) as the negative electrode with the potential windows of 0–1.6 V the device exhibits a maximum energy density of 25.7 Wh kg-1 at a power density of 2800 W kg-1 and an excellent cycling stability of 83.51% after 10,000 cycles, indicating that the device has excellent rate capability and cycle stability.