Lithium Ion Batteries: State of the Art in Performance and Safety

Authors

Prof. Dr. M. Winter, Jülich Research Center Helmholtz Institute, Münster; A. Friesen MSc, Dr. F. M. Schappacher, Münster University MEET Battery Research Center

Year

2017

Print Info

Fortschritt-Berichte VDI, Series 12, No 802

Summary

Lithium ion cells are established electrochemical energy storage systems with high efficiencies and high energy and power densities. The typical lithium ion cell is based on a carbon-based anode and a layered transition metal oxide cathode. The key to high capacities and energy and power densities lies in the optimized and new materials as well as in the design of electrodes, battery cells, modules and systems. The energy density is determined only on the material level. The combination of anodes with high capacities and low potential and cathodes with high capacities and high potentials determines the cell voltage and cell capacity. This results in the energy density. The power density of lithium ion cells is mainly determined by the design of electrodes. The electrode can be customized for high power or high energy applications, whereas the power density is reached at the cost of energy density. Safety of lithium ion cells is an important factor for the broad acceptance, especially in the EV application. The continuous increase in the energy density leads to the decrease of thermal stability of the cell materials. Thus, to increase the safety active and passive measures on the material, cell and system level are required.