State of the art of commercial Li ion batteries

A number of criterial specific parameters of the electrodes in five commercial Li ion batteries of leading producers are derived on the basis of the recently published data by Johnson and White [B.A. Johnson, R.E. White, J. Power Sources 70 (1998) 48]. The impact of these parameters on the cycling performance of the cells is analyzed. It is shown that in spite of the similarities in the type of the electrode, electrolyte and separator materials, there are considerable differences in the capacity, masses, apparent densities and material balance ratio. For example the A&T cell with the smallest masses of its active electrode materials and lowest apparent densities of the electrodes has achieved the largest cell capacity, highest rate capability and cycling stability. This is accomplished thanks to the high quality of its electrode materials' novel electrode design with double current collectors for each electrode and largest material balance ratio. The above and other examples in the paper reveal the complexity of interactions between the criterial parameters of the electrodes and indicate that an improvement in the cell performance requires not only investigations but creativity as well. (C) 2000 Elsevier Science S.A. All rights reserved.