Hierarchical NiCo₂S₄ hollow spheres as a high performance anode for lithium ion batteries

Abstract

Hierarchical NiCo 2 S 4 hollow spheres are successfully fabricated by a facile hydrothermal method accompanied by high-temperature annealing and anion exchange process. By using NiCo 2 S 4 hollow spheres as anode material for Lithium ion batteries, a high specific capacity of 696 mAh g -1 can be obtained after 100 cycles at the current density of 200 mA g -1 . Even at the current density of 2000 mA g -1 , the specific capacity still maintains at 411 mAh g -1 after 50 cycles. The good electrochemical performance can be attributed to the unique porous feature and void spaces within the surface of hollow spheres, which provide large contact areas between electrolyte and active materials for electrolyte diffusion and alleviate the volume change during the lithium-ion insertion/extraction process.

NiCo2S4 Nanosheets Grown on 3D Networks of Nitrogen‐Doped Graphene/Carbon Nanotubes: Advanced Anode Materials for Lithium‐Ion Batteries

“…Furthermore, the pore‐size distribution of NiCo 2 S 4 /NGC‐2 hybrid calculated from the Barrett–Joiner–Halenda method is mainly centered at about 4 nm (inset of Figure ), which is in the mesoporous range. Porous structures with higher specific surface area are advantageous for electrode materials, which can facilitate rapid diffusion of lithium ions to access active materials and accommodate the volumetric expansion of active materials during the lithiation/delithiation process …”

“…Porous structures with highers pecific surfacea rea are advantageous for electrode materials,w hich can facilitater apid diffusion of lithium ions to access active materials and accommodate the volumetric expansion of active materials during the lithiation/delithiation process. [42][43][44]…”

Porous Core–Shell CuCo2S4 Nanospheres as Anode Material for Enhanced Lithium‐Ion Batteries

“…The reaction mechanism of NiCo 2 S 4 and Li + can be depicted as follows: NiCo 2 S 4 +8Li + +8 e−→Ni+2Co+4Li 2 S and Ni+Li 2 S↔NiS+2Li and Co+Li 2 S↔CoS+2Li. Both the capacity and rate capability are superior to those of pure NiS or CoS . More recently, various CuCo 2 S 4 nanomaterials (e.g., nanoarrays, nanosheets, and hollow spheres) have drawn much attention because of their lower resistivity (approximately 10 −4 Ω) and stable structure.…”

Mixed Metal Sulfides for Electrochemical Energy Storage and Conversion

“…Nanostructuring is an effective approach to address this critical issue. [97,98,214,215] For example, by employing NiCo 2 O 4 hollow microspheres as template, Jin et al reported a method to www.advenergymat.de synthesize 3D urchin-like NiCo 2 S 4 hollow microspheres. [215] As revealed by the CV test, the reaction mechanism between NiCo 2 S 4 and Li + can be described as follows: NiCo 2 S 4 + 8Li + + 8e − → Ni + 2Co + 4Li 2 S; Ni + Li 2 S ↔ NiS + 2Li and Co + Li 2 S ↔ CoS + 2Li.…”

“…[97,98,214,215] For example, by employing NiCo 2 O 4 hollow microspheres as template, Jin et al reported a method to www.advenergymat.de synthesize 3D urchin-like NiCo 2 S 4 hollow microspheres. [215] As revealed by the CV test, the reaction mechanism between NiCo 2 S 4 and Li + can be described as follows: NiCo 2 S 4 + 8Li + + 8e − → Ni + 2Co + 4Li 2 S; Ni + Li 2 S ↔ NiS + 2Li and Co + Li 2 S ↔ CoS + 2Li. When used as an anode material for LIBs, the NiCo 2 S 4 hollow microspheres delivered a first discharge and charge capacity of 1251 and 1016 mA h g −1 at 200 mA g −1 , respectively, corresponding to a Coulombic efficiency of 81%.…”