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Ben Richards and Tobias Hanrath
Center for Future Energy
Systems
Feb 26, 2015
Scalable Fabrication of
Silicon Nanowire Anodes
2 cm
- scientific and engineering principles for scalable manufacturing of
semiconductor nanowires via roll-to-roll (R2R) manufacturing processes.
Scalable Fabrication of Silicon Nanowire Anodes
Nissan Leaf
[LIB] 24 kWh; 270 kg
150 miles
100
~ 7000 cells !
1320 lbs.
Limitations of currently available EV batteries:
- Performance
- Weight
- Co$t !
anode
(graphite) cathode
(Li1+xMn2O4)
Charge and Energy Storage Capacity
of next-generation battery materials.
exciting scientific breakthroughs
for new battery materials
0
1500
3000
4500
6000
2000 2002 2004 2006 2008 2010 2012
Li ion battery
scientific papers / year
scalability and integration of nanomaterials
85 kWh
~40 kg Si nanowires
Scalability Limitations of Chemical Vapor Deposition
(Thin Film Technologies)
thin film processing technologies adopted from the
microelectronics fabrication are ill-suited for manufacturing
battery materials at technologically relevant scales.
loading requirements for high capacity batteries
(a)
Al
Cu (b)
Design for nanomanufacturing:
Requirements for Si nanowire anodes in battery
applications
- scalable, high-throughput manufacturing.
- integrated material fabrication and device processing
- high loading
- stable electrochemical cycling, tolerance for mechanical
stresses due to volume dilation.
gen1: Supercritical Fluid Nanowire Synthesis
High throughput Ge nanowire synthesis in super-
critical fluid
High-pressure / high-temperature CSTR reactor
gen II: supercritical fluid Nanowire Synthesis
gen III: supercritical fluid nanowire synthesis
high throughput synthesis: 2g!
- continuous flow synthesis
- multi-zone temperature control
- integrating synthesis and surface
treatment
Nanowire growth on bulk metal films
gen IV: nanowire synthesis directly on metal surface
Chem Mater 23, 4838–4843 (2011).
Uncovering basic mechanism governing nanowire
growth from bulk metals.
1. Journal of Materials Chemistry C 2, no. 10 (2014): 1699–1678. doi:10.1039/C3TC31666A,
(i)
(iv) (ii)
nanowire growth mechanism
depth
(v)
Cu Ge
(iii)
1. Richards, B. T., Gaskey, B., Levin, B. D. A., Whitham, K., Muller, D., and Hanrath, T.
“Direct Growth of Germanium and Silicon Nanowires on Metal Films ”
Journal of Materials Chemistry C 2, no. 10 (2014): 1699–1678.
doi:10.1039/C3TC31666A,
(i)
(iv) (ii)
depth
(v)
Cu Ge
(iii)
1. Richards, B. T., Gaskey, B., Levin, B. D. A., Whitham, K., Muller, D., and Hanrath, T.
“Direct Growth of Germanium and Silicon Nanowires on Metal Films ”
Journal of Materials Chemistry C 2, no. 10 (2014): 1699–1678.
doi:10.1039/C3TC31666A,
nanowire growth mechanism
activate nanowire growth directly on the surface of the metal.
- scientific and engineering principles for scalable manufacturing of
semiconductor nanowires via R2R manufacturing processes.
Can we exploit the direct growth on metal
surfaces for a roll-to-roll process ?
electrochemical characterization of nanowire films
nanowires are in direct contact with the metal current
collector and exhibit negligible contact resistance
electrochemical characterization of nanowire films
capacity fade in wires grown directly from the metal ( ) is less
pronounced than in a wire-paste deposited onto the wire ( )
2 cm
Summary
direct growth of Si nanowires on metal foils presents an exciting
opportunity to develop scalable nanofabrication technology to
resolve impending bottlenecks in our transition towards
nanomaterials in energy storage.
outstanding scientific and technological challenges to bring the
prospect of Si-based high-capacity anodes to technological
fruition.
2 cm
Benjamin Richards
Kevin Whitham
Katie Silberstein
Barnaby Levin
Jie Gao
Bernard Gaskey
Charles Hamilton
Samuel Schraer
Eric McShane
Heather Barton
Jacob Quintana
THANKS