Growth mechanism and electrochemical properties of hierarchical hollow SnO₂ microspheres with a “chestnut” morphology

Abstract

aeHierarchical hollow microspheres (HHMSs) constitute a very popular class of materials for use as drugdelivery carriers, photocatalysts and electrode materials in batteries, owing to their large, porous surface area and mechanical integrity during intercalation reactions. Here, we used a template-and additive-free hydrothermal route to prepare an unusually shaped SnO 2 material that comprises a hollow spherical morphology with uniform diameters and very thin petal-like nano-sheets grown perpendicularly on the sphere's surface, resembling a "chestnut cupule". We thoroughly investigated the formation mechanism by 119 Sn Mössbauer spectroscopy, powder X-ray diffraction and X-ray photoelectron spectroscopy. Key to this process is the ultrasonic pre-treatment of an aqueous SnCl 2 solution, followed by Ostwald "inside-out" ripening upon hydrothermal processing. This unique morphology has greatly improved the storage capacity and cycling performance of SnO 2 as an anode material for lithium and sodium ion batteries compared with conventional SnO 2 materials.

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

“…In contrast to conventional SnO 2 materials, this unique morphology signicantly improved the storage capacity and cycling performance of SnO 2 as an anode material for lithium and sodium ion batteries. 206 In addition, 3D hierarchical SnO 2 nanomaterials can be assembled by 0D, 1D, and 2D SnO 2 nanomaterials. For example, 0D crystalline SnO 2 nanoparticles were successfully assembled into a high-order nanostructure of hollow core-shell.…”

“…In contrast to conventional SnO 2 materials, this unique morphology significantly improved the storage capacity and cycling performance of SnO 2 as an anode material for lithium and sodium ion batteries. 206 …”

Rice husk-derived carbon@SnO2@graphene anode with stable electrochemical performance used in lithium-ion batteries

“…Various methods have been proposed for solving this problem. One of the effective strategies is to minimize the material to reduce the size of the particles and to prepare the special morphology of the SnO 2 materials, such as nanowires [10], nanorods [11] and spherical [12] materials. Another effective method is to load SnO 2 particles on the substrate to form a composite.…”