title: Facile synthesis and lithium storage properties of a porous NiSi2/Si/carbon composite anode material for lithium-ion batteries.
abstract: In this work, a novel, porous structured NiSi2/Si composite material with a core-shell morphology was successfully prepared using a facile ball-milling method. Furthermore, the chemical vapor deposition (CVD) method is deployed to coat the NiSi2/Si phase with a thin carbon layer to further enhance the surface electronic conductivity and to mechanically stabilize the whole composite structure. The morphology and porosity of the composite material was evaluated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and nitrogen adsorption measurements (BJH analysis). The as-prepared composite material consists of NiSi2, silicon, and carbon phases, in which the NiSi2 phase is embedded in a silicon matrix having homogeneously distributed pores, while the surface of this composite is coated with a carbon layer. The electrochemical characterization shows that the porous and core-shell structure of the composite anode material can effectively absorb and buffer the immense volume changes of silicon during the lithiation/delithiation process. The obtained NiSi2/Si/carbon composite anode material displays an outstanding electrochemical performance, which gives a stable capacity of 1272 mAh g(-1) for 200 cycles at a charge/discharge rate of 1C and a good rate capability with a reversible capacity of 740 mAh g(-1) at a rate of 5C.
authors.affiliation: MEET Battery Research Center, Institute of Physical Chemistry, University of Münster , Corrensstrasse 46, 48149 Münster, Germany.
authors.forename: Haiping
authors.initials: H
authors.lastname: Jia
authors.forename: Christoph
authors.initials: C
authors.lastname: Stock
authors.forename: Richard
authors.initials: R
authors.lastname: Kloepsch
authors.forename: Xin
authors.initials: X
authors.lastname: He
authors.forename: Juan Pablo
authors.initials: JP
authors.lastname: Badillo
authors.forename: Olga
authors.initials: O
authors.lastname: Fromm
authors.forename: Britta
authors.initials: B
authors.lastname: Vortmann
authors.forename: Martin
authors.initials: M
authors.lastname: Winter
authors.forename: Tobias
authors.initials: T
authors.lastname: Placke
keywords: NiSi2/Si composite; anode material; ball milling; lithium-ion batteries; porous structure