FY2010 - Oak Ridge National Laboratory

Seed Money Fund—
Materials Science and Technology Division
Mission Relevance
DOE is strongly promoting transportation electrification, which is critical for reducing the nation’s
dependence on oil and reducing emissions. The future of electric vehicles largely depends upon the
development of battery technologies. Lithium-ion batteries have shown the best potential, but their energy
and power densities are far from adequate; therefore, technical breakthroughs are urgently needed. This
project will develop novel silicon micro/nanowires-based anode materials that, if successfully developed,
are expected to significantly increase the capacity and power density for lithium-ion batteries.
The technology, if successful, will potentially increase the charge capacity and power density for lithiumion
batteries and benefit other federal agencies such as the Department of Transportation and the
Department of Defense, including Army, Navy, Air Force, Defense Advanced Research Projects Agency,
and Defense Threat Reduction Agency.
Results and Accomplishments
In FY 2010 we successfully fabricated copper-silicon core-shell nanowire arrays. The nanowires are
several micrometers long with shell diameters of 300–350 nm and core diameters of 150–200 nm. Raman
spectroscopy examination indicated that the silicon shells are primarily in the amorphous phase, which is
preferred for the anode application. First, a couple of two-electrode coin-type half-cells have been
assembled for the copper-silicon nanowire arrays. Galvanostatic cycling was carried out in a potential
range of 2.0–0.005 V using a constant current charge–discharge protocol at rates from C/30 to 10C. The
initial testing results are very encouraging: (1) great potential for high capacity—the capacity for the first
two cells reached ~1000 mAh/g, already 3 the theoretical capacity of a conventional graphite anode, and
the capacity can be further increased by increasing the Si/Cu ratio with the potential up to 3000 mAh/g;
(2) excellent capacity retention with 95% after 39 cycles at various charge–discharge rates;
(3) insignificant capacity drop for a higher charge–discharge rate up to 1C due to the highly conductive
copper core; and (4) near 100% coulombic efficiency after the first cycle. No silicon pulverization or
core-shell delamination was detected under scanning electron microscopy after 50+ charge–discharge
cycles.
The planned work for FY 2011 includes (1) improvement on the nanowire distribution and morphology,
(2) reduction of SiO x on the nanowire surface to decrease the irreversible capacity, (3) characterizations
of the nonstructural and compositional evolutions induced by lithium-ion insertion–extraction, and
(4) further electrochemical evaluation using half-cell and/or full-cell configurations.
05866
Synthesis of High-Performance Lignin-Derived Biothermoplastics
Rebecca H. Brown, Tomonori Saito, Deanna L. Pickel, Joseph M. Pickel, Frederick S. Baker, and
Amit K. Naskar
Project Description
Lignin is the second most abundant natural polymer, accounting for up to 30% by weight of wood. Lignin
is a valuable by-product of the paper and pulp industry that is currently utilized in a variety of low-value
applications and as fuel for the paper mills. The overarching intent of this project is to establish chemical
synthetic routes for producing lignin-based thermoplastics, which will increase the value of lignin
by-products. Today’s available lignin-based bioplastics are primarily thermosets, and therefore
nonrecyclable. This project aims to move well beyond current state-of-the-art lignin products
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