First Introduction of NiSe2 to Anode Material for Sodium-Ion Batteries: A Hybrid of Graphene-Wrapped NiSe2/C Porous Nanofiber

Abstract

The first-ever study of nickel selenide materials as efficient anode materials for Na-ion rechargeable batteries is conducted using the electrospinning process. NiSe2-reduced graphene oxide (rGO)-C composite nanofibers are successfully prepared via electrospinning and a subsequent selenization process. The electrospun nanofibers giving rise to these porous-structured composite nanofibers with optimum amount of amorphous C are obtained from the polystyrene to polyacrylonitrile ratio of 1/4. These composite nanofibers also consist of uniformly distributed single-crystalline NiSe2 nanocrystals that have a mean size of 27 nm. In contrast, the densely structured bare NiSe2 nanofibers formed via selenization of the pure NiO nanofibers consist of large crystallites. The initial discharge capacities of the NiSe2-rGO-C composite and bare NiSe2 nanofibers at a current density of 200 mA g−1 are 717 and 755 mA h g−1, respectively. However, the respective 100th-cycle discharge capacities of the former and latter are 468 and 35 mA h g−1. Electrochemical impedance spectroscopy measurements reveal the structural stability of the composite nanofibers during repeated Na-ion insertion and extraction processes. The excellent Na-ion storage properties of these nanofibers are attributed to this structural stability.

Golden Bristlegrass‐Like Hierarchical Graphene Nanofibers Entangled with N‐Doped CNTs Containing CoSe2 Nanocrystals at Each Node as Anodes for High‐Rate Sodium‐Ion Batteries

“…However, the relatively low initial Coulombic efficiency of the N-CNT/rGO/CoSe 2 NF was mainly due to the high initial irreversible capacity loss of C materials, such as N-CNT, rGO, and GC, for Na + -ion storage. [49,50] However, the degree of irreversibility during the first cycle could be effectively reduced by pre-sodiation of the electrode material. [51,52] The cycling performance of the nanofibers at a current density of 0.5 A g −1 with the carbonate-based electrolytes is shown in Figure 6e.…”

Mesh-structured N-doped graphene@Sb2Se3 hybrids as an anode for large capacity sodium-ion batteries

“…Recently, extensive efforts have been focused on high performance transition-metal selenides materials with analogous structure of graphite, such as MoSe 2 [7,8], FeSe 2 [9,10], NiSe 2 [11] and CuSe 2 [12], and results show good sodium storage performance. As one of the important selenides, Sb 2 Se 3 with a direct narrow-band gap and highly anisotropic semiconducting nature has been widely explored in various research fields and displayed good chemical stability and excellent photovoltaic properties [13,14].…”

High Potential of Aerosol‐Made 3D Graphene‐Based Composites for Enhanced Energy Storage

“…SIBs have recently shown great interest in large‐scale potential energy storage systems . However, electrode materials must be capable of overcoming the slow sodium‐ion diffusion kinetics and resist structural breakdown during the charge–discharge process, often in relation to the large ionic radius of sodium . In recent years, various metal sulfides combined with GR as effective electrode materials of SIBs have been extensively studied .…”

“…However, the heavier mass and larger radius of Na + are leading to lower electrochemistry and larger volume changes of the active materials than the smaller Li + . To solve these problems, rational electrode designs which combine nanomaterials with GR can be an effective approach . Recently, aerosol‐made 3D GR‐based composites were introduced for application to SIBs.…”