Lithium-ion storage performances of sunflower-like and nano-sized hollow SnO₂ spheres by spray pyrolysis and the nanoscale Kirkendall effect

Abstract

Nanostructured metal selenides with a variety of morphologies are crucial for fabricating porous, hollow metal-oxide nanomaterials by nanoscale Kirkendall diffusion. Herein, SnSe-SnO2 composite powders and SnSe nanospheres were synthesized via one-pot spray pyrolysis by optimizing the concentration of the Se precursor in the spray solution; these were then used to fabricate sunflower-like SnO2 and hollow SnO2 nanospheres, respectively, via nanoscale Kirkendall diffusion. Post-treatment of the SnSe-decorated SnO2 under air produced sunflower-like SnO2, in which ray and disk florets consisting of hollow nanoplates and dense nanospheres, respectively, were present. The mean diameter of the homogeneous hollow SnO2 nanospheres was 150 nm. The hollow morphology shortens the diffusion length, increasing the contact area between the electrolyte and voids and buffering large volume changes during repeated cycling. As anode materials for lithium-ion batteries, the hollow SnO2 nanospheres showed excellent cycling and rate performances. The discharge capacity of the hollow SnO2 nanospheres, after 500 cycles from 0.001 V to 3.0 V, was 1043 mA h g-1, at a current density of 3.0 A g-1. The hollow SnO2 nanospheres showed a high reversible capacity of 638 mA h g-1, even at current density as high as 10 A g-1.

Synthesis Process of CoSeO3 Microspheres for Unordinary Li‐ion Storage Performances and Mechanism of Their Conversion Reaction with Li ions

“…Therefore, direct oxidation of CoSe x nanocrystals should cause their transformation into hollow cobalt oxide via nanoscale Kirkendall diffusion. [26,27] However, in this study, the CoSe x nanocrystals transformed into a porous structure composed of CoSeO 3 ultrafine nanocrystals. In the initial oxidation step, the thin layers of CoSeO 3 were formed onto surface of CoSe 2 nanocrystal.…”

“…If direct oxidation of CoSe x nanocrystals into cobalt oxide occurs, the Se component should diffuse into the outer layer of the nanocrystals because the diffusion rate of Se is faster than that of O 2 gas molecules which could not be penetrated due to dense surface in the initial oxidation step. Therefore, direct oxidation of CoSe x nanocrystals should cause their transformation into hollow cobalt oxide via nanoscale Kirkendall diffusion . However, in this study, the CoSe x nanocrystals transformed into a porous structure composed of CoSeO 3 ultrafine nanocrystals.…”

Hierarchical Hollow‐Microsphere Metal–Selenide@Carbon Composites with Rational Surface Engineering for Advanced Sodium Storage

“…For instance, hollow NiO nano‐octahedrons were successfully prepared without templates, delivering ultralarge Li‐storage capability . The obtained sunflower‐like SnO 2 delivered remarkable rate ability, keeping superior lithium‐ion storage performance …”

“…[33][34][35][36] For instance, hollow NiO nano-octahedrons were successfully prepared without templates, delivering ultralarge Li-storage capability. [38] Also, the incorporation with carbon was used as another effective manner, which could boost the accommodating of volume change, the trapping of by-products and so on. [38] Also, the incorporation with carbon was used as another effective manner, which could boost the accommodating of volume change, the trapping of by-products and so on.…”

Tin dioxide-based nanomaterials as anodes for lithium-ion batteries

“…86 Various 3D nanostructures have been synthesized, such as hollow spheres 91,[192][193][194] and microboxes. [195][196][197] Furthermore, many new synthetic methods to prepare SnO 2 hollow structures, including Ostwald ripening, [198][199][200] Kirkendall effect, [201][202][203][204] removable templates 195 and chemically induced selfassembly 192,205 have been reported.…”