3D emerging nanosheets comprising hierarchical CoMoO4/MnO2 composites for flexible all-solid-state asymmetric supercapacitors

Abstract

Flexible and portable energy storage gadgets have aroused mounting interest because of the remarkable achievement in the field of intelligent and wearable devices. In this paper, perpendicularly organized CoMoO4/MnO2 (CMO/MO) heterostructures are produced in situ on the surface of Ni foam, and the porous 3D architectures and rough nanoplates outside could offer substantial active sites and decrease the ion diffusion distances. Such splendid architecture with massive electrochemically active sites exhibits greater areal capacity in contrast to CoMoO4. Subsequently, an all-solid-state asymmetric supercapacitor (ASSC) based on the CMO/MO and PVA/KOH gel electrolyte is prepared. The ASSC could work under high voltages ranging from 0 to 1.4 V and deliver a maximum areal capacitance of 0.467 Fcm−2 (1 mAcm−2). It also exhibits a great energy density of 35.81 Wh kg−1 at a watt density of 198.22 W kg−1, and the capacity retention could keep 75% even after 8000 cycles. Collectively, this research offers enlightenment regarding the synthesis of electrode materials.