Acknowledgements
The authors thank Dr. D.-Z. Sun from the Fraunhofer Institute for
Mechanics of Materials IWM for valuable discussions, and Mr.
Huberth and his co-workers from the Fraunhofer Ernst Mach
Institute EMI in Freiburg for performing the CT analysis. Thanks are
due to Dr. Bergmann, Dr. O. Nolte and Dr. F. Seyfried fromVWGroup
Research for valuable discussions and partial financial support. The
support of GAIA Akkumulatorenwerke GmbH is acknowledged.