Three-Dimensional Self-Standing and Conductive MnCO₃@Graphene/CNT Networks for Flexible Asymmetric Supercapacitors

Abstract

The practical applications of flexible supercapacitor depend strongly on the successful fabrication of advanced electrode materials with high electrochemical performance. Herein, three-dimensional conductive network-based self-standing MnCO3@graphene/CNT hybrid film fabricated through a combination of a hydrothermal method and vacuum filtration for flexible solid-state supercapacitors is reported. The MnCO3@graphene structure is embedded in a CNT network, in which monodispersed MnCO3 nanorod is well confined in graphene nanosheets. This hierarchical structure provides rapid electron/electrolyte ion transport pathways and exhibits excellent structural stability, resulting in rapid kinetics and a long life cycle. The MnCO3@graphene/CNT electrode delivers high specific capacity (467.2 F g–1 at 1 A g–1). Asymmetric supercapacitor (ASC) devices are assembled with the MnCO3@graphene/CNT film as positive electrode and activated carbon/carbon cloth as negative electrode, which exhibits a high energy density of 27 W h kg–1. Remarkably, 93% capacitance retention is obtained for the ASC devices after 6000 cycles.

Defect Induced in 3D-Rhombohedral MnCO3 Microcrystals by Substitution of Transition Metals for Aqueous and Solid-State Hybrid Supercapacitors

“…To overcome these issues, a common strategy is followed by researchers, i.e., the addition of high electrical conductivity materials (CNTs, rGO, and bioderived carbons) to the host materials and making of composites. 24,25 Another viable alternative is defect engineering; different types of transition metal (Fe, Co, Ni, etc.) heteroatom doping/substitution in the host material could endow abundant active sites.…”

Structure‐Designed Preparation of Pod‐Like CuCo2S4/rGO as Advanced Anode Material Targeting Superior Sodium Storage

“…In addition, ordered graphitic structures of GO, rGO and pod‐like CuCo 2 S 4 /rGO can be confirmed by the Raman spectra in Figure 3b. There are two prominent peaks located at 1350 cm −1 and 1590 cm −1 for all as‐prepared samples, which are associated with the vibrations of sp 3 carbon atoms (D band) and sp 2 carbon atoms (G band), respectively [37,38] . The disorder and defect lattice concentration of graphitic carbon materials can be measured by the intensity ratio of D and G bands (I D /I G ).…”

Recent advances in the interface design of solid-state electrolytes for solid-state energy storage devices

“…Our previous study 233 A good interfacial contact between electrodes and SSE can effectively improve the electrochemical performance in SSESDs. Our works suggested that the in-situ solidification of SSEs is a promising strategy to improve the interfacial contact between electrodes and SSEs and achieve the industrialization of high-performance SSESDs 237,238 .…”