As the use of battery chemistries evolves to provide more energy density, power capabilities and longevity, optimal selection for a given application becomes increasingly important. This presentation will cover the pros and cons of LiCoO2, LiNiMnCoO2 and LiNiCoAlO2 chemistries. We will also review new chemistry trends, such as silicon cells, and look ahead five years from now towards solid electrolyte Li cells and high-voltage cathodes.