Lithium Ion Conduction in Oxides

Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, Scotland 

Of course, the main feature of a crystal, and what distinguishes it from other solids, is that it contains order. Conceptually, we describe crystals as being formed from a perfectly ordered array of atoms or molecules. This order has a helpful consequence by describing a small portion of the structure and the symmetry of crystal we can map out the atomic positions of an infinite lattice. The power of this approach is beguiling. It allows us to map all of the atoms in a crystal, which may be metres in 

Functional Oxides Edited by Duncan W. Bruce, Dermot O Hare and Richard I. Walton 2010 John Wiley c Sons, Ltd. 

Polymeric materials containing dissolved lithium salts are currently used as electrolytes and a range of polymer/solvent systems have been studied. These materials perform effectively and have some considerable 

The discussion here is a brief summary of some of the considerations in a simple model for lithium conduction in an ionic solid. In practice, the movement of a lithium ion may be strongly correlated the vibrational modes of the lattice and the movement of other lithium ions and is likely to involve some degree of local relaxation of the lattice around sites which switch from containing vacancies to accommodating a lithium ion. In some remarkable cases, such as lithium sulfate, the lithium ion conductivity is associated with partial melting of the anion sublattice within the crystalline material. Despite the complexities of individual systems the basic hopping model provides a useful framework to discuss ion conductivity in the solid state and it is supported by considerable experimental evidence. 

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