Rose-like VS₂ Nanosheets Chemically Anchored on Carbon Nanotubes for Flexible Zinc-Ion Batteries with Enhanced Properties

Abstract

Rechargeable aqueous zinc-ion batteries (ZIBs) are an attractive alternative for flexible energy storage devices due to their excellent safety and low cost. One of the main challenges that plagues their practical applications is the restricted variety of cathode materials with fast reaction kinetics and good mechanical properties. Herein, we prepared rose-like VS2 nanosheets which have decent specific capacities, metallic conductivity, and open-enough channels and further incorporated them into a single-walled carbon nanotube (SWCNT) network, achieving a C–V chemical-bonded freestanding VS2@SWCNT (C-VS2) composite. Such chemical bonding in the composites builds a bridge for rapid electron transfer and ion diffusion in the longitudinal direction from one layer to another layer. As a result, the reversible Zn/C-VS2 system in core cells exhibits a high specific capacity (205.3 mA h g–1 at 0.1 A g–1), an excellent cyclic stability (115.4 mA h g–1 was obtained after 1500 cycles at 5 A g–1), and a remarkable rate capability (135.4 mA h g–1 at 10 A g–1). Furthermore, the freestanding C-VS2 films with good flexibility and conductivity can serve as a flexible cathode to assemble soft-packaged ZIBs. Meanwhile, the soft-packaged ZIB has good electrochemical stability even under different bending conditions (the discharge capacity dropped by only 2.1 mA h g–1 after bending). This work offers insights into the rational design of zinc-ion hosts throughout chemical bond engineering.

Perspective of Vanadium Disulfide: A Rising Star Finds Plenty of Room in Single and Multielectron Energy Storage

“…In addition, it shows stable energy storage in aqueous zinc-ion flexible energy storage equipment. 89 In addition, doping heteroatoms (usually nitrogen, N) can improve the reaction activity of carbon, and the high affinity of doped N for transition metals (TMs) can form a strong coupling with vanadium-based compounds, showing extraordinary electrochemical performance. 188−192 As an example, Liu et al prepared shuttle-like VS 2 nanocrystals grown on the layer of N-doped carbon.…”

“…The single-walled nanotube network provides a good conductive network and avoids the stacking of VS 2 nanosheets. In addition, it shows stable energy storage in aqueous zinc-ion flexible energy storage equipment …”

Design Strategies and Recent Advancements for Low‐Temperature Aqueous Rechargeable Energy Storage

“…Aqueous rechargeable energy storage (ARES) mainly including aqueous ion batteries, aqueous supercapacitors, and aqueous ion capacitors has been considered as a promising complement to the commercially energy storage technologies based organic electrolytes due to their cost-effectiveness and high safety. [1][2][3][4] However, the intrinsic weakness of frequently being frozen of aqueous electrolytes reduces their low-temperature adaptability and cannot fulfill the requirements of human activities expansion, such as polar research, outdoor exploration, high-altitude region expedition, and military action, which require efficient and sustainable power supply under extreme environment. [5][6][7] In addition, electrochemical impedance spectroscopy revealed that both the solution resistance and charge transfer resistance deteriorated rapidly when the operation temperature was near to its freezing point, resulting in inevitable performance atom (Figure 1c).…”

Experimental and Theoretical Indagation of Binder-Free N-Graphene Coupling Vanadium Tetrasulfide Aerogel Cathode for Promoting Aqueous Zn-Ion Storage

“…For the past few years, layered vanadium-based compounds (VCs) have been demonstrated to own fascinating energy storage properties as cathode materials in the AZIB system by both theoretical predication and experimental realization. − As one member of the VCs, vanadium disulfide (VS 2 ) has been synthesized and exploited extensively as a host material in storage of zinc ions owing to its layered architecture and large interlayer spacing of 0.576 nm. ,, However, the stacked structures of layered VS 2 always confine the convenient diffusion of electrons and ions in a two-dimensional (2D) plane, impeding their rapid transport between cathodes and anodes, especially at high currents. As another member of VCs, vanadium tetrasulfide (VS 4 ) crystal has a one-dimensional (1D) atomic chain architecture composed of tetravalence vanadium ions coordinated with S 2 2– dimes.…”

“…The low electrical conduction, sluggish ion diffusion dynamics, morphology agglomeration, structural collapse, and solubility in aqueous electrolytes during repeated charge and discharge procedures lead to an unsatisfactory electrochemical real performance of VCs, which greatly impedes its further application in AZIBs. Accordingly, efficient reliable routes including construction of a micro/nano-structure and introduction of carbonaceous materials with excellent mechanical and conductive properties have been taken to deal with the aforementioned drawbacks. ,, At present, several carbonaceous materials have been used to compound with VC micro/nano materials to meliorate their energy storage performance. ,, Among them, graphene has drawn considerable concerns thanks to its distinct physicochemical properties. Nevertheless, in view of the existence of π–π interactions and strong van der Waals working force in the graphene nanolayers, their aggregation and restack occurred frequently, resulting in the inheritance of a graphite nature. , This is unfavorable for the utilization of graphene on high-performance energy storage systems.…”