Recent Progress on Two-Dimensional Nanoflake Ensembles for Energy Storage Applications

Abstract

The rational design and synthesis of two-dimensional (2D) nanoflake ensemble-based materials have garnered great attention owing to the properties of the components of these materials, such as high mechanical flexibility, high specific surface area, numerous active sites, chemical stability, and superior electrical and thermal conductivity. These properties render the 2D ensembles great choices as alternative electrode materials for electrochemical energy storage systems. More recently, recognition of the numerous advantages of these 2D ensemble structures has led to the realization that the performance of certain devices could be significantly enhanced by utilizing three-dimensional (3D) architectures that can furnish an increased number of active sites. The present review summarizes the recent progress in 2D ensemble-based materials for energy storage applications, including supercapacitors, lithium-ion batteries, and sodium-ion batteries. Further, perspectives relating to the challenges and opportunities in this promising research area are discussed.

Facile Synthesis of Binary Transition Metal Sulfide Tubes Derived from NiCo‐MOF‐74 for High‐Performance Supercapacitors

“…During the hydrothermal process, restacking of 2D crystallites contributed to the formation of mesopores with a uniform size of ≈5 nm and an enhancement in the specific surface area of NiCo‐S. The unique hierarchical architectures with 2D nanoflakes and porous structure provided electronic transport and ion transfer channels, increased the contact area between the electrolyte and active materials because of large specific surface area, and hence improved the electrochemical reaction kinetics …”

“…The unique hierarchical architectures with 2D nanoflakes and porous structure provided electronic transport and ion transfer channels, increased the contact area between the electrolyte and active materials because of large specific surface area, and hence improved the electrochemical reaction kinetics. [47,48] The electrochemical performance of NiCo-O, NiCo-P, and NiCo-S electrodes was evaluated with a standard three-electrode system, and the results are shown in Figure 5. The cyclic voltammetry (CV) curves of NiCo-S at different scan rates exhibit a pair of well-defined redox peaks, signifying a faradaic redox characteristic of capacitive behavior.…”

The electrochemical properties of reduced graphene oxide film with capsular pores prepared by using oxalic acid as template

“…upsurge for EDLCs because of its high theoretical specific surface area (SSA), high thermal conductivity, and good electrical conductivity. [16][17][18] Up to date, template method has drawn considerable attention to control the structure of the carbonaceous materials. 6,15 Rationally designing and precisely controlling the structures of carbon-based materials is the effective route to obtain the electrode materials with novel functions and extraordinary properties.…”

“…6,15 Rationally designing and precisely controlling the structures of carbon-based materials is the effective route to obtain the electrode materials with novel functions and extraordinary properties. [16][17][18] Up to date, template method has drawn considerable attention to control the structure of the carbonaceous materials. 7,19 For example, threedimensional networks of carbon nanocage with multiscale pores have been designed by carbonizing and activating the carbon precursor coated on flower-like basic magnesium carbonate microspheres 20 ; by using soft template, the bowl-shaped hollow carbon sphere has also been prepared by combining the hydrothermal and carbonizing method.…”

Flexible Planar‐Integrated Micro‐Supercapacitors from Electrochemically Exfoliated Graphene as Advanced Electrodes Prepared by Flash Foam–Assisted Stamp Technique on Paper

“…In recent years, the rapid development of flexible and wearable electronics has promoted the strong demand for miniaturizing and bendable energy storage devices. [1][2][3][4][5][6][7][8][9][10] Micro-sized energy storage devices, especially flexible planar-integrated microsupercapacitors (MSCs), have received much attention due to their several advantages in terms of small size, high power density, ultra-fast charging/discharging rate, excellent cycling stability, extraordinary mechanical flexibility, and fulfilling operational safety. [8] Compared with the sandwich construction of traditional supercapacitors, the planarintegrated structure is more conducive to improving power density due to the more expedient and rapid migration of electrolyte ions.…”