V2O5/single-walled carbon nanotube hybrid mesoporous films as cathodes with high-rate capacities for rechargeable lithium ion batteries

• Published in: Nano energy 2013-07, Vol.2 (4), p.481-490
• Main Authors: Cao, Zeyuan, Wei, Bingqing
• Format: Article
• Language: English
• Subjects: Applied sciences; Chemical vapor deposition (including plasma-enhanced cvd, mocvd, etc.); Cross-disciplinary physics: materials science; rheology; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Exact sciences and technology; High-rate-capacity cathodes; Hybrid mesoporous films; Lithium ion batteries; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Nanocrystalline materials; Nanoscale materials and structures: fabrication and characterization; Nanotubes; Physics; Single-walled carbon nanotube; Vanadium pentoxide
• ISSN: 2211-2855
• DOI: 10.1016/j.nanoen.2012.11.013

The hybrid films composed of V2O5 nanoparticles and single-walled carbon nanotubes (V2O5/SWNT) with mesoporous structure are prepared using a simple floating CVD method followed by controllably hydrolytic deposition of V2O5 nanoparticles. The hybrid films as cathodes for lithium ion batteries exhibit a high-rate capacity of 548mAhg−1 at the discharge rate of 300mAg−1 (∼1C); 342mAhg−1 and 171mAhg−1 at higher discharge rates of 1200mAg−1 (∼4C) and 2400mAg−1 (∼8C), which is attributed to the chemical interaction between the V2O5 nanoparticle and the functional groups on the surface of SWNTs evidenced by the HRTEM and XPS results. It is also conclusively elucidated with detailed electrochemicl analysis that SWNTs can improve Li+ diffusivity by 2 to 4 orders of magnitude to significantly facilitate lithium-ion transport, achieving an excellent electrochemical performance of the hybrid cathode system. V2O5/SWNT hybrid mesoporous films were synthesized by a facile method and the electrochemical properties of the hybrid films have been systematically investigated. The hybrid films as cathodes for lithium ion batteries show high-rate capacities. It is the intimate chemical interaction between V2O5 nanoparticle and the functional groups of SWNTs that improve electrochemical kinetics of V2O5 greatly to lead to the excellent electrochemical performance. [Display omitted] ► A facile method to prepare V2O5/SWNT hybrid films as cathode materials for lithium ion batteries. ► A high-rate capacity of 548mAhg−1 at the discharge rate of 300mAg−1 (∼1C) was achieved. ► Specific capacity of 171mAhg−1 at higher discharge rate of 2400mAg−1 (∼8C) was also achieved. ► 2–4 orders of magnitude improvement of Li+ diffusivity was achieved via V2O5-SWNT interactions.