A facile synthetic strategy of free-standing holey graphene paper as sulfur host for high-performance flexible lithium sulfur batteries

Multifunctional integrated VN/V2O5 heterostructure sulfur hosts for advanced lithium-sulfur batteries

Lithium-sulfur (Li-S) batteries show great potential in future electric transportation and large-scale grid storage applications because of their attractive theoretical energy density (2600 W h kg^-1) and relatively abundant sulfur reserves. However, the rapid capacity decay and unsatisfactory sulfur loading caused by the lithium polysulphide (LiPS) dissolution and low electrical conductivity of sulfur are the most urgent issues plaguing its practical applications. Herein, we report a multifunctional nanoporous (NP) VN/V₂O₅ binary host that can efficiently resolve the above conflicts by the synergy between the functions of two materials. The inner V₂O₅ facilitates rapid trapping of numerous LiPSs while the outer porous VN with abundant NP channels offers high conductivity and mild chemisorption, thereby improving the localization and catalytic conversion ability of LiPSs. Accordingly, the designed cathodes with 1.87 mg cm^-2 sulfur content achieve an acceptable areal specific capacity (2.72 mA h cm^-2), excellent rate capability (963 mA h g^-1 at 5.0C), and cycling stability. Remarkably, the cathodes with ultrahigh sulfur loading of 9.02 mg cm^-2 deliver a satisfactory areal specific capacity (12.12 mA h cm^-2) and still maintain excellent durability.

Synthesis of holey graphene for advanced nanotechnological applications

Holey or porous graphene, a structural derivative of graphene, has attracted immense attention due to its unique properties and potential applications in different branches of science and technology. In this review, the synthesis methods of holey or porous graphene/graphene oxide are systematically summarized and their potential applications in different areas are discussed. The process–structure–applications are explained, which helps relate the synthesis approaches to their corresponding key applications. The review paper is anticipated to benefit the readers in understanding the different synthesis methods of holey graphene, their key parameters to control the pore size distribution, advantages and limitations, and their potential applications in various fields.

The review paper presents a systematic understanding of different synthesis routes to obtain holey graphene, its properties, and key applications in different fields. The article also evaluates the current progress and future opportunities of HG.

Graphene-Based Nanomaterials as the Cathode for Lithium-Sulfur Batteries

The global energy crisis and environmental problems are becoming increasingly serious. It is now urgent to vigorously develop an efficient energy storage system. Lithium-sulfur batteries (LSBs) are considered to be one of the most promising candidates for next-generation energy storage systems due to their high energy density. Sulfur is abundant on Earth, low-cost, and environmentally friendly, which is consistent with the characteristics of new clean energy. Although LSBs possess numerous advantages, they still suffer from numerous problems such as the dissolution and diffusion of sulfur intermediate products during the discharge process, the expansion of the electrode volume, and so on, which severely limit their further development. Graphene is a two-dimensional crystal material with a single atomic layer thickness and honeycomb bonding structure formed by sp2 hybridization of carbon atoms. Since its discovery in 2004, graphene has attracted worldwide attention due to its excellent physical and chemical properties. Herein, this review summarizes the latest developments in graphene frameworks, heteroatom-modified graphene, and graphene composite frameworks in sulfur cathodes. Moreover, the challenges and future development of graphene-based sulfur cathodes are also discussed.