In Situ Generation of Few-Layer Graphene Coatings on SnO₂-SiC Core-Shell Nanoparticles for High-Performance Lithium-Ion Storage

Journal Article · Wed Nov 16 04:00:00 EST 2011 · Advanced Energy Materials

DOI:https://doi.org/10.1002/aenm.201100464· OSTI ID:1035407

Chen, Zhongxue; Zhou, Min; Cao, Yuliang; Ai, Xinping; Yang, Hanxi; Liu, Jun

A simple ball-milling method is used to synthesize a tin oxide-silicon carbide/few-layer graphene core-shell structure in which nanometer-sized SnO₂ particles are uniformly dispersed on a supporting SiC core and encapsulated with few-layer graphene coatings by in situ mechanical peeling. The SnO₂-SiC/G nanocomposite material delivers a high reversible capacity of 810 mA h g^-1 and 83% capacity retention over 150 charge/discharge cycles between 1.5 and 0.01 V at a rate of 0.1 A g^-1. A high reversible capacity of 425 mA h g^-1 also can be obtained at a rate of 2 A g^-1. When discharged (Li extraction) to a higher potential at 3.0 V (vs. Li/Li⁺), the SnO₂-SiC/G nanocomposite material delivers a reversible capacity of 1451 mA h g^-1 (based on the SnO₂ mass), which corresponds to 97% of the expected theoretical capacity (1494 mA h g^-1, 8.4 equivalent of lithium per SnO₂), and exhibits good cyclability. This result suggests that the core-shell nanostructure can achieve a completely reversible transformation from Li_4.4Sn to SnO₂ during discharging (i.e., Li extraction by dealloying and a reversible conversion reaction, generating 8.4 electrons). Finally, this suggests that simple mechanical milling can be a powerful approach to improve the stability of high-performance electrode materials involving structural conversion and transformation.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1035407
• Report Number(s): PNNL-SA-83376; 43997; KC0201050
• Journal Information: Advanced Energy Materials, Journal Name: Advanced Energy Materials Journal Issue: 1 Vol. 2; ISSN 1614-6832
• Publisher: Wiley
• Country of Publication: United States
• Language: English

Related Subjects

Environmental Molecular Sciences Laboratory