Free-Standing SnO2@rGO Anode via the Anti-solvent-assisted Precipitation for Superior Lithium Storage Performance

Abstract

Metal oxides have been attractive as high-capacity anode materials for lithium-ion batteries. However, oxide anodes encounter drastic volumetric changes during lithium ion storage through the conversion reaction and alloying/dealloying processes, leading to rapid capacity decay and poor cycling stability. Here, we report a free-standing SnO 2 @reduced graphene oxide (SnO 2 @rGO) composite anode, in which SnO 2 nanoparticles are tightly wrapped within wrinkled rGO sheets. The SnO 2 @rGO sheet is assembled in high porosity via an anti-solvent-assisted precipitation of dispersed SnO 2 nanoparticles and graphene oxide sheets in the distilled water, followed by the filtration and post-annealing processes. Significantly enhanced lithium storage performance has been obtained of the SnO 2 @rGO anode compared with the bare SnO 2 anode material. A high charge capacity above 700 mAh g −1 can be achieved with a satisfying 95.6% retention after 50 cycles at a current density of 500 mA g −1 , superior to reserved 126 mAh g −1 and a much lower 16.8% retention of the bare SnO 2 anode. XRD pattern and HRTEM images of the cycled SnO 2 @rGO anode material verify the expected oxidation of Sn to SnO 2 at the fully-charged state in the 50th cycle. In addition, FESEM and TEM images reveal the well-preserved free-standing structure after cycling, which accounts for high reversible capacity and excellent cycling stability of such a SnO 2 @rGO anode. This work provides a promising SnO 2-based anode for high-capacity lithium-ion batteries, together with an effective fabrication adoptable to prepare different free-standing composite materials for device applications.

A Highly Sensitive Room Temperature CO2 Gas Sensor Based on SnO2-rGO Hybrid Composite

“…FESEM was conducted to characterize the surface morphology of the rGO and SnO 2 -rGO composite. As depicted in Figure 3 a, under 50 kX magnification, wrinkles made of stacks of single rGO layers can be found everywhere on the surface, which matches with amorphous rGO characteristics [ 36 ]. As vividly demonstrated in Figure 3 b, synthesized SnO 2 -rGO consists of highly crystalline and spherical constituents, which verify the existence of SnO 2 .…”

Nanostructured Graphene Oxide-Based Hybrids as Anodes for Lithium-Ion Batteries

“…Jiang et al [203] developed a SnO 2 /rGO nanocomposite, which showed an initial specific capacity of 1705 mAh g −1 and a capacity retention of 500 mAh•g −1 after 50 cycles at 250 mA g −1 . A free-standing SnO 2 @rGO composite anode, in which SnO 2 nanoparticles were tightly wrapped within wrinkled rGO sheets, was synthesized via an anti-solvent-assisted precipitation [204]. The SnO 2 @rGO anode showed significant enhanced lithium storage behavior; a high charge capacity above 700 mAh g −1 was achieved with 95.6% retention after 50 cycles at a current density of 0.5 A g −1 .…”

Overcoming the Challenges of Freestanding Tin Oxide‐Based Composite Anodes to Achieve High Capacity and Increased Cycling Stability

“…In order to address those issues new electrode materials are explored, implying in case of the anode that the currently used graphite with its rather low theoretical capacity of 372 mAh g −1 has to be replaced. [ 1–4 ]…”

“…SnO 2 attracted lots of attention as a promising alternative featuring a high theoretical capacity of 1494 mAh g −1 and a low working potential. [ 1–3,5 ] Lithiation and delithiation of SnO 2 can be subdivided into two main steps. In a first step, SnO 2 undergoes a conversion reaction resulting in the formation of metallic Sn embedded into a Li 2 O matrix followed by alloying reactions between lithium and the previously formed Sn phase yielding Li x Sn (0 ≤ x ≤ 4.4).…”