The Microwave Facile Synthesis of NiOx@graphene Nanocomposites for Application in Supercapacitors: Insights into the Formation and Storage Mechanisms

Recently, the strategy of combining carbon-based materials with metal oxides to enhance the electrochemical performance of electrodes has been a topic of great interest, but research focusing on the growth and charge storage mechanisms of such hybrid electrodes has rarely been conducted. In this work, a simple, reproducible, low-cost, and fast microwave heating method was used to synthesize NiOx@graphene nanocomposites. NiOx@graphene nanocomposites were used as a model system for exploring the growth and charge storage mechanisms of the hybrid electrode materials due to their simple preparation process, good stability, low cost, and high specific capacitance. The effects of reaction conditions (the type of metal precursor and feeding ratio between the nickel precursor and graphene) on the formation mechanism of the electrodes were examined, and it was demonstrated that the microstructure and morphology of the electrode materials were metal precursor-dependent, which was directly related to the electrochemical performance of the electrodes. Our work provides a new affordable approach to the synthesis of, and experimental support for designing, hybrid electrode architectures with a high electrochemical performance for next-generation energy storage devices.

Automated summary

In recent years, combining carbon-based materials with metal oxides to improve the electrochemical performance of electrodes has attracted great interest. However, research on the growth and charge storage mechanisms of such hybrid electrodes has been limited. This study synthesized NiOx@graphene nanocomposites using a simple, reproducible, low-cost, and fast method, and explored their growth and charge storage mechanisms. It was found that the microstructure and morphology of the electrode materials were dependent on the choice of metal precursor, which directly affected the electrochemical performance of the electrodes. This work provides a new affordable approach for the synthesis and design of hybrid electrode architectures with high electrochemical performance, and offers experimental support.