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Pilot-scale continuous synthesis of a vanadium-doped LiFePO4/C nanocomposite high-rate cathodes for lithium-ion batteries

2015; Elsevier BV; Volume: 302; Linguagem: Inglês

10.1016/j.jpowsour.2015.10.068

1873-2755

I. Johnson, Mechthild Lübke, On Ying Wu, Neel M. Makwana, Glen J. Smales, Husn U. Islam, Rashmi Y. Dedigama, Robert I. Gruar, Christopher J. Tighe, David O. Scanlon, Furio Corà, Dan J. L. Brett, Paul R. Shearing, Jawwad A. Darr,

Supercapacitor Materials and Fabrication

A high performance vanadium-doped LiFePO4 (LFP) electrode is synthesized using a continuous hydrothermal method at a production rate of 6 kg per day. The supercritical water reagent rapidly generates core/shell nanoparticles with a thin, continuous carbon coating on the surface of LFP, which aids electron transport dynamics across the particle surface. Vanadium dopant concentration has a profound effect on the performance of LFP, where the composition LiFe0.95V0.05PO4, achieves a specific discharge capacity which is among the highest in the comparable literature (119 mA h g−1 at a discharge rate of 1500 mA g−1). Additionally, a combination of X-ray absorption spectroscopy analysis and hybrid-exchange density functional theory, suggest that vanadium ions replace both phosphorous and iron in the structure, thereby facilitating Li+ diffusion due to Li+ vacancy generation and changes in the crystal structure.