The design of a lithium polymer battery with excellent properties is presented. The focus is on cathode and anode active materials and their influence on cell properties like energy density and cycle behavior. Standard LiCoO2 is compared with alternative cathode materials like Li–Co–Ni–Mn–O and high density LiCoO2. Furthermore, several natural graphites and their mixtures with synthetic graphite are discussed as potential anode active material as natural graphite is attractive concerning price. The good performance of VARTA Microbattery's PoLiFlex™ lithium polymer battery results from an adequate combination of cathode and anode formulations.