Porous SnO₂/Graphene Composites as Anode Materials for Lithium-Ion Batteries: Morphology Control and Performance Improvement

Abstract

The rational design of graphene-encapsulated nanomaterials is of great significance to the high-rate and long-cycle anode materials in lithium-ion batteries. Herein, composites of three-dimensional reduced graphene oxide-encapsulated SnO 2 nanoparticles (SnO 2 /RGO) have been synthesized by combining hydrothermal treatment with spray drying or freeze drying, and finally calcination. The morphology of a SnO 2 /RGO composite can be controlled and SnO 2 /RGO microspheres obtained by spray drying possess a large specific surface area and abundant inner spaces. Such kinds of morphology and porosity characteristics cannot only provide sufficient interior void to buffer the large volume variation but also provide an effective contacting area of electrolyte with electrode materials and more active sites for a redox reaction, which effectively avoids shedding of active components during lithiation/delithiation. The obtained SnO 2 /RGO shows a high specific capacity of 1592 mA h g −1 after 500 cycles at 500 mA g −1 , and it can maintain 319 mA h g −1 even at 5 A g −1 .

A nanostructured SnO2/Ni/CNT composite as an anode for Li ion batteries

“…can enhance the electronic conductivity of SnO 2 and the mechanical strength, also cushioning massive volume changes. 10,14,17,18 Similar observations were recorded in our earlier publication, which reported that upon the addition of carbon, stability in terms of the capacity is observed, where carbon accommodated the strain of volume change and increased the conductivity of pristine SnO 2 . 19 However, the mere addition of carbonaceous materials to SnO 2 does not overcome all the issues.…”

“…12,13 To overcome these drawbacks, researchers have tried to modify SnO 2 via synthesizing SnO 2 with a variety of morphologies, such as nanoparticles; hollow nanostructures; tube-like, rod-like, and wirelike morphologies; etc. 14,15 Efforts have also been made to prepare nanocomposites of SnO 2 with carbonaceous materials, transition metals, or other metal oxides as buffering matrices. 11,16 It is reported that the addition of a carbonaceous buffering matrix (e.g., carbon nanotubes (CNTs), graphene, carbon nanobers (CNFs), etc.)…”

APCVD Graphene-Based Composite Electrodes for Li-Ion Batteries

“…Nevertheless, other materials could be examined, including metal oxides such as tin oxide (SnO 2 ) and iron oxide (Fe 2 O 3 ) due to the raised energy density, abundant resources, safety, and low cost and toxicity. It is worth noting that the theoretical capacities of SnO 2 and Fe 2 O 3 are 782 and 1007 mA h g −1 [40] respectively, being higher than the commercial graphite (372 mA h g −1 ) [16].…”

“…Lu et al found that the 3D reduced graphene oxide-encapsulated SnO 2 nanoparticles showed a specific capacity of 1592 mAh g −1 after 500 cycles at 500 mA g −1 , preserving a value of 319 mAh g −1 even at 5 A g −1 . This structure can successfully reduce volume collapse and provide enhanced Li + and electron kinetics during the intercalation/deintercalation process [16]. Additionally, the doping of metal nanoparticles such as N, P, S, and B atoms can provide more active sites, offering an efficient way to improve the capacity of graphene [7,12].…”

Na3V2(PO4)2F3@bagasse carbon as cathode material for lithium/sodium hybrid ion battery

“…The main reason was that the Na 3 V 2 (PO 4 ) 2 F 3 /C-20% prepared by spray drying had a nano-scale spherical morphology and the surface was covered with a carbon coating, which increased the electronic conductivity and ion diffusivity. 44–46…”