WFU Joint Physics, Chemistry, and CEES^* Colloquium

TITLE: Materials -- The Technology Barrier to Advanced Batteries for Energy Storage

SPEAKER: Professor M. Stanley Whittingham ,

TIME: Wednesday March 2, 2011 at 4:00 PM

PLACE: Room 101 Olin Physical Laboratory

Energy storage is the enabling technology for renewable energy, such as wind and solar, and particularly for the next generation of hybrid electric vehicles, the plug-in hybrid electric vehicle (PHEV). If long-lived, low cost and safe batteries are to be developed, the materials limitations must be overcome. Intercalation is the predominant reaction mechanism in rechargeable batteries in use today. Intercalation processes, unlike conversion reactions, allow for fast ionic motion both on both lithium insertion and lithium removal. Moreover the structural maintenance during reaction permits essentially unlimited cycling of the material. Intercalation can occur within a single phase as originally demonstrated in titanium disulfide, or with the formation of a second phase, as demonstrated most recently in the vanadyl phosphates. Although two-phase reactions were thought to be rate-limiting, such is not necessarily the case with the phosphate finding extensive use in hybrid electric buses.

This presentation will discuss the present status of materials, both bulk and nano, for the next generation of batteries, with an emphasis on the cathodes for lithium-ion batteries both high rate and high capacity. The status of "high-energy" systems such as Li/air and Li/S will also be described.