Silicon-Graphite Electrode Performance in Lithium Ion Batteries: From Coin Cells to 500 Mah-Pouch Cells

Current lithium ion anode and cathode materials cannot meet the desired gravimetric and volumetric energy demands for hybrid electric vehicles (HEV), plug in hybrid electric vehicles (PHEV) and pure electric vehicles (EV).  One way to improve the performance of these systems is to develop a high energy anode material.  One system that has shown promise is the incorporation of silicon particles into the anode.  Silicon by itself can have capacities up to 3000 mAh/g.  While this value is impressive, there are a number of issues that present themselves when trying to use all of that capacity.

Argonne National Laboratory has taken up the task to create a silicon-based anode that could be used with the current lithium ion cathode materials to increase the gravimetric and volumetric energy of these systems.  The capacity target for this electrode was chosen to be between 600-800 mAh/g (active material).  By selecting this value, systems modeling has shown that this anode capacity matched with current cathode materials would produce the most cost effective and energy dense systems.

This presentation will first focus on some of the initial development of the anode formulation and processing issues encountered.  From there, coin cell data (Figure 1) will be presented on the anode formulation and then the presentation will conclude with xx3450 pouch cell data.  Qualitative and quantitative data will be examined for each of the sections.

As a final point, the silicon anode formulation has been made into a practical and usable electrode and matched to the Electrode Library which has been created by the Cell Analysis, Modeling, and Prototyping (CAMP) Facility.  The silicon based anode, graphite based anodes, and various cathodes are available in the Electrode Library for use in the battery research community.

 Acknowledgment:

Support from Peter Faguy and David Howell of the U.S. Department of Energy’s Office of Vehicle Technologies Program is gratefully acknowledged.  This work was performed under the auspices of the U.S. Department of Energy, Office of Vehicle Technologies, under Contract no.  DE-AC02-06CH11357