Hierarchical sandwich NiFe layered double hydroxide/reduced graphene oxide for high energy density asymmetric supercapacitors

Rational design and fabrication of composite electrode materials with high energy storage performance of supercapacitors is of great importance from both theoretical and practical viewpoints. Herein, a hierarchical sandwich-type NiFe layered double hydroxide/reduced graphene Oxide (NiFe-LDHs/rGO) composite electrode materials were successfully synthesized through a one-step hydrothermal method. It is found that the prepared NiFe-LDHs/rGO composite electrode can achieve a high specific capacitance of 1319F g(-1) at 1 A g(-1) and show good cycling performance with a retention rate of 80% over 1000 cycles. Furthermore, the asymmetric supercapacitor based on NiFe-LDHs/rGO as a positive electrode and N-doped hollow carbon sphere as a negative electrode was assembled and exhibited a high energy density of 37 Wh kg(-1) at a power density of 423 W kg(-1) as well as good cycling stability. The exceptional electrochemical performance of the NiFe-LDHs/rGO composite indicates its potential application in high-performance supercapacitors.

Automated summary

In this study, a hierarchical sandwich-type NiFe layered double hydroxide/reduced graphene oxide (NiFe-LDHs/rGO) composite electrode material was successfully synthesized. The composite electrode exhibited high specific capacitance and good cycling performance. Additionally, an asymmetric supercapacitor assembled with NiFe-LDHs/rGO as the positive electrode demonstrated high energy density and cycling stability. These results indicate the potential application of NiFe-LDHs/rGO composite in high-performance supercapacitors.