High-performanced flexible solid supercapacitor based on the hierarchical MnCo2O4 micro-flower

• Hierarchical MnCo 2 O 4 micro-flower is synthesized with nanoboxes carbon as template. • The MnCo 2 O 4 micro-flower has 102.67% initial capacity retention after 10,000 cycles. • The fabricated material is also suitable for flexible all-solid supercapacitors. Transition metal oxides have attracted much attention in supercapacitors(SCs) research field due to their eco-friendly characteristics and high theoretical specific capacity. However, the slow reaction kinetics process and poor long-cycle performance hinder its potential application. To overcome these shortcomings, MnCo 2 O 4 micro-flowers (MnCo 2 O 4 -MF) with hierarchical structure were prepared. The spinel MnCo 2 O 4 has a variety of metal valence states, which can provide more electrochemical active sites compared to mono-metal oxides. Moreover, the unique hierarchical structure of MnCo 2 O 4 -MF shortens the transmission distance of ions and electrons, and reduce the volume expansion and structural collapse during the cycles. Benefiting from the crystal phase and structure advantages of MnCo 2 O 4 -MF, the reaction kinetics process was accelerated and it showed excellent long-cycle stability. In aqueous alkaline electrolyte, MnCo 2 O 4 -MF exhibits an ultra-high specific capacity of 1230 F g −1 at a current density of 1 A g −1 . Even after 10,000 cycles at 10 A g −1 , the capacity of 102.67% is still maintained. In addition, we constructed the sandwich structured flexible flexible hybrid solid supercapacitor (FHSC) based on MnCo 2 O 4 -MF // carbon nanoboxes. The FHSC devices not only expand the working voltage window of SCs, but also show flexibility and excellent electrochemical performance.