V. Focused Fundamental Research - EERE - U.S. Department of ...

V.C.12 Silicon Clathrates for Anode Applications in Lithium-Ion Batteries (SwRI)
Chan, Miller – SwRI
1.2
Normalized Intensity (Counts)
1.0
0.8
0.6
0.4
0.2
Product
BaSi 2
Control
Ba 8
Si 46
Calculated
0.0
10 20 30 40 50 60
2 (deg)
Figure V - 119: Powder X-ray diffraction pattern of the 5 GPa product is compared with that of BaSi2 and the positions of major reflections theoretically
predicted for pure Ba8Si46.
Direct Synthesis of Guest-Free Clathrate. A
plasma-enhanced magnetron sputtering (PEMS) vacuum
deposition chamber was set up to explore the synthesis
of guest-free silicon clathrate particles by directing a
silicon-argon plasma into a pool of ionic liquid (IL), as
illustrated in Figure V - 120.
Two different ionic liquids were utilized and both
produced small quantities of guest-free Si 46, which was
confirmed by Raman Spectroscopy. Figure V - 121 presents
an image of empty Si 46 synthesized by PEMS, while
Figure V - 122 shows the results of Raman spectroscopy.
of deposition plasma directed over pool of IL. (C) Image of IL pool
following PEMS deposition and recovered IL containing nano-particles of
silicon clathrate (D).
Figure V - 121: Image of empty Si46 produced by PEMS.
Figure V - 120: (A) PEMS deposition chamber and setup for depositing
nano-particles of silicon clathrate (guest free) into a pool of IL. (B) Image
Energy Storage R &D 582 FY 2011 Annual Progress Report