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

V.C.8 Metal-Based High-Capacity Li-Ion Anodes (Binghamton U.) Whittingham – Binghamton U.
Little loss of capacity was observed up to 3 mA/cm 2 , with
a slight loss at 8 mA/cm 2 , equivalent to a 3C rate. The
cycling efficiency exceeded 99% for currents of 3 mA/cm 2
or less. At 8 mA/cm 2 the efficiency dropped to 98%. Figure
V - 103 (b) shows that the hysteresis in the cycling curve
increases markedly at 8 mA/cm 2 . The Ragone plot in the
inset shows the excellent rate capability.
Conclusions and Future Directions
A clear result from our earlier understanding of the
cycling behavior of amorphous nano SnCo anode materials
is that nano/amorphous materials work, and that bulk
materials with their high expansion on lithium reaction do
not and are therefore unsuitable for batteries. Thus, our
project targeted mimicking the SnCo material, and this was
successfully accomplished using the Sn 2 Fe compound.
However, it has an unacceptably high first cycle capacity
loss which must be overcome. Silicon formed in a
reductive mechanochemical reaction showed good cycling
and capacity retention. Our future work will include
preparing these tin and silicon compounds by at least one
more method and evaluating the effect of synthesis
approach on the electrochemical properties.
FY 2011 Publications/Presentations
Figure V - 103: Rate capability of Si/MgO/graphite electrode between 0.01 V
and 1.5 V. (a) capacity cycling at different current density; (b) lithium
insertion/removal curve at different rates, and Ragone plot for Li insertion. 1
C rate = 2.8 mA/cm 2 . The first cycle current density was 0.3 mA/cm 2 . For
current = 1.5, 3, 8 mA/cm 2 , the Li/SMOG half cell was discharged to 0.01V
and held at 0.01 V for 2 hours before charged.
1. Presentation to the 2011 DOE Annual Peer Review
Meeting.
2. Wenchao Zhou, Shailesh Upreti and M. Stanley
Whittingham “Electrochemical performance of Al-Si-
Graphite composite as anode for lithium-ion
batteries”, Electrochemistry Communications, 2011,
13: 158-161.
3. Wenchao Zhou, Shailesh Upreti, and M. Stanley
Whittingham, “High performance Si/MgO/graphite
composite as the anode for lithium-ion batteries”,
Electrochemistry Communications, 2011, 13: 1102­
1104.
4. Ruigang Zhang, Shailesh Upreti and M. Stanley
Whittingham, “Tin-Iron Based Nano-Materials as
Anodes for Li-Ion Batteries”, J. Electrochem. Soc.,
2011, (12): in press.
5. Many invited presentations, including:
o Electrochemical Society, Materials Research
Society, Pacific Power Sources Conf., IBA
o U. C. San Diego, Stony Brook U., Wake Forest
U., Michigan State U.
o ORNL, Haldor Topsoe-Copenhagen
o Local outreach
Energy Storage R &D 566 FY 2011 Annual Progress Report