Expanding the Capabilities of LithiumIon Batteries

1
Expanding the Capabilities of Lithium-Ion
Batteries

• Benjamin J Privett
• October 27, 2004
• Centre College

2
The Modern Portable Power Crisis

• Portable electronics more features smaller
  size need for smaller, more powerful batteries
• Problem
• Moore's Law Microchips will double in power
  every 2 years
• No analogous law for batteries
• Consequences new technologies being shelved and
  innovation stymied by lack of good power source

3
Power Consumption Culprits

• Digital Cameras
• Image sensors and processors
• Laptops
• LCD screens consume 35 of power used
• Microchips
• More processing power more energy consumed

4
What can be done?

• Decrease power consumption
• More efficient components
• Fuel cells
• Expensive
• Widespread use years away
• Increase capacity of batteries
• Improve current cells
• Li-ion battery materials

5
Battery Basics
6
Earlier Lithium Batteries

• Why Lithium?
• Lightest of all metals
• High electrochemical potential
• Lithium metal anode dissolves in liquid
  electrolyte and deposits Li onto cathode.
• Problem
• Ribbon buildup ? short circuit and explosion
• Can only be used in primary (non-rechargeable)
  batteries.

7
The Next Step Li-Ions

• Li ions in matrix instead of metal
• Graphite matrix widely used
• Will keep overall shape of anode while still
  allowing high-capacity Li-ion storage.
• Limited Li capacity of graphite (372 mA h g-1)

8
New Anode Material Metallic Sn

• Produced by making a LiSn alloy
• Advantages
• can contain a high concentration of Li up to
  Li17Sn4.
• Li can be inserted electrochemically and
  reversibly.
• Theoretical capacity of 992 mA h/g.
• Problems
• Causes expansion and contraction of anode.
• Weakens Sn structure

9
Solution SnO nano-particles

• Keep metal particles small, and you reduce volume
  change
• SnO nano-particles produced by sonocating
  (ultrasonic radiation) during synthesis to keep
  particles small.
• Advantages
• Reduces problems with volume change because more
  flexible structure.
• Problems
• Aggregation during electrochemical reaction ?
  again pulverizes Sn

10
Solution Sn-Encapsulated Spherical Hollow Carbon

• Encapsulate Sn particles in spherical carbon
  shell.
• Keeps Sn from aggregating.
• Allows Sn particles to change volume without
  breaking shell

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Synthesis
Add TBPT Sn Source
12
Does this work?
Sn-encapsulated Spherical Hollow Carbon Very
little capacity fade after 10 cycles
Sn and Spherical carbon mixture High capacity
fade after 10 cycles
13
Results

• Reached 705 mA h/g
• 70 of theoretical capacity
• Provides an effective band-aid until better
  technologies are developed
• This and similar Li-ion technologies currently
  being tested

14
References

• Aurbach, Doron, et al. "Nanoparticles of SnO
  Produced by Sonochemistry as Anode Materials for
  Rechargeable Lithium Batteries." Chem. Mater. 14
  (3003) 4155-4163. 22 Oct. 2004
  lthttp//www.pubs.acs.orggt.
• Blacklight Power, Inc.. 22 Oct. 2004
  lthttp//www.blacklightpower.com/battery.shtmlgt.
• Buchmann, Isidor. Will Lithium-Ion Batteries
  Power the New Millenium. Darnell Group Inc. 22
  Oct. 2004 lthttp//www.powerpulse.net/powerpulse/gt.
  
• DeGaspari, John. "Rethinking Lithium." Mechanical
  Engineering Magazine June 2001. 23 Oct. 2004
  lthttp//www.memagazine.org/backissues/june01/featu
  res/lithium/lithium.htmlgt.
• Jung, Yoon S., Kyu T. Lee, and Seung M. Oh.
  "Synthesis of Tin-Encapsulated Spherical Hollow
  Carbon for Anode Material in Lithium Secondary
  Batteries." J. Am. Chem. Soc. 125 (2003)
  5652-5653. 22 Oct. 2004 lthttp//www.pubs.acs.org/gt
  .
• Lithium Ion Batteries. Aug. 2003. Panasonic. 22
  Oct. 2004 lthttp//www.panasonic.com/industrial/bat
  tery/oem/images/pdf/panasonic_LiIon_overview.pdfgt.