Raspberry-like Ni/NiO/CoO/Mn3O4 hierarchical structures as novel electrode material for high-performance all-solid-state asymmetric supercapacitors

摘要

Hybrid transitional metals oxides have been attracted more and more attention in the field of supercapacitors. However, the design of structure and composition of materials is always a challenge due to tedious preparation process and difficult structure construction. Based on above issue, we construct novel raspberry-like Ni/NiO/CoO/Mn3O4 hierarchical structures (NNCMs) with excellent electrochemical performances by one-step hydro thermal process in this work. The introduction of metallic Ni and well-designed hierarchical structures can result in well improved conductivity for electrode material, sufficient channels and active sites for electrolyte ions to enter and contact with electrode material. The NNCMs-16 electrode exhibits a high specific capacitance of 1964 F g(-1) and superior cycling stability (95% of initial specific capacitance after 10000 cycles). The assembled NNCMs-16//AC device delivers outstanding energy densities of 70.4 Wh kg(-1) at power densities of 794.5 W kg(-1). Thus, the raspberry-like NNCMs-16 hierarchical structures can be regarded as promising materials for practical supercapacitors and this work also provides a valuable reference for the preparation and application of high performance electrode materials.