Growth of nickel phosphide films as anodes for lithium-ion batteries: Based on a novel method for synthesis of nickel films using ionic liquids

• Published in: Electrochimica acta 2013-12, Vol.112, p.212-220
• Main Authors: Lu, Y., Gu, C.D., Ge, X., Zhang, H., Huang, S., Zhao, X.Y., Wang, X.L., Tu, J.P., Mao, S.X.
• Format: Article
• Language: English
• Subjects: Anodes; Chlorides; Choline; Electrodeposition; Ionic liquid; Ionic liquids; Lithium-ion batteries; Lithium-ion battery; Morphology; Ni-P film; Nickel; Phosphides
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2013.09.035

•Ni-P films with different surface morphologies and thicknesses were successfully synthesized.•Ni-P films were grown based on Ni films which were electrodeposited using ionic liquids.•Ni2P film obtained by Ni electrodeposition for 30min exhibits a rough surface with plenty of pores.•Ni2P film delivered a discharge capacity of 398.5mAhg−1 with the capacity retention of 91.4%.•The film exhibits a capacity increase with cycling phenomena relating to its surface morphology. Nickel phosphide (Ni-P) films were fabricated through four types of Ni films electrodeposited using a choline chloride-based ionic liquid (choline chloride-ethylene glycol) at room temperature. Sheet-like morphology of Ni films can be obtained when 0.5M of Ni2+ is used; and sphere-like one is presented by 1.0M of Ni2+. Consequently, the surface morphologies of these Ni-P films were affected by the initial Ni films. And different phases of Ni12P5 and Ni2P in the Ni-P films would be obtained after the phosphorization process. As anodes for Li-ion batteries, the electrochemical properties of these Ni-P films were investigated by cyclic voltammetry and galvanostatic charge–discharge tests. The surface morphology and thickness of thin films had a significant effect on their electrochemical performance. The Ni2P films delivered a large reversible discharge capacity around 398.5mAhg−1 with the capacity retention of 91.4% after 50 cycles.