Center for Functional Nanomaterials Colloquium Series

"Nanomaterials for High Performance Li-ion Batteries: Challenges and Opportunities"

Presented by Weiqiang Han, Brookhaven National Laboratory

Tuesday, February 21, 2012, 11:00 am — Bldg. 735 - Seminar Room, 2nd floor

Rechargeable Li-ion batteries are key components of the portable electrical devices, electric vehicles and grid storage energy. Nanostructured materials offer a tremendous potential for high performance Li-ion batteries. In recent years, many researchers have focused on resolving one crucial problem of capacity fading in Li-ion batteries when carbon anodes are replaced by other IV–elements (Si, Ge, or Sn) with much higher capacities. In this presentation, I present a brief review of CFN efforts in developing novel nanomaterials and nanostructures to resolve this crucial problem in the past three years. Three significant examples are: (1) amorphous hierarchical porous GeOx whose primary particles are ~3.7 nm has a very stable capacity of ~1,250 mAh g-1 for 600 cycles; (2) the discovering a new phase of FeSn5, which has the so-far highest theoretical capacity of 929 mAh g-1 (Fe0.74¬Sn5 with iron vacancies) among the reported M(electrochemically inactive)-Sn systems; (3) first work of using Magnéli phases TinO2n-1 as anodes for Li-ion batteries. I will discuss the challenges and opportunities that remain regarding synthesis, microstructure, electrochemistry performance and mechanism of these systems.
References:
1. X.-L. Wang, W.-Q. Han, H. Chen, J. Bai, T. A. Tyson, X.-Q. Yu, X.-J. Wang, X.-Q. Yang, “Amorphous Hierarchical Porous GeOx as High-Capacity Anodes for Li Ion Batteries with Very Long Cycling Life” J. Amer. Chem. Soc. 133 (2011) 20692-20695.
2. Xiao-Liang Wang, Mikhail Feygenson, Haiyan Chen, Chia-Hui Lin, Wei Ku, Jianming Bai, Meigan C. Aronson, Trevor A. Tyson, and Wei-Qiang Han, “Nanospheres of a New Intermetallic FeSn5 Phase: Synthesis, magnetic properties and anode performance in Li-ion batteries”, J. Am. Chem. Soc. 133, 11213-11219 (2011).
3. W. –Q. Han and X. -L. Wang, Carbon-coated Magnéli-phase TinO2n−1 nanobelts as anodes for Li-ion batteries and hybrid electrochemical cells, Appl. Phys.

Hosted by: Chuck Black

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