Status of Lithium-Sulfur Batteries: Lessons Learned and Remaining Challenges

Kurzfassung

Lithium sulfur (Li-S) cells are promising batteries both for automotive and stationary applications. The main advantages of this type of cell are the high theoretical capacity (1675 Ahkg−1), high energy density (2500 Whkg−1) and low cost of sulfur (S) and other materials. However, degradation of the cathode, electrolyte decomposition, self-discharge and low sulfur fraction in the cathode are major problems for the technical realization of this novel battery. In addition, effective manufacturing with high output is required. Regarding the cycling stability several parallel reactions and phase changes which occur during cycling, as well as the different solubility of sulfur and its polysulfide reaction intermediates, negatively affect the cycling stability of the cell. Nevertheless, significant progress in the last five years has been reported recently, especially with regard to continuous improvement on the cycling stability1,2. In this contribution we will discuss shortly the status of the development in general, present in situ and ex situ techniques that have been already developed to get a deeper understanding on reaction mechanisms and degradation processes1-6. Moreover, it is important to incorporate the information gained from the experimental characterization into models to maximize the optimization of the battery. Models can reveal additional understanding and predict the behavior over a full range of battery operation under different conditions. Modeling and simulations7,8 of electrochemical processes during cycling of Li-S batteries and the description of the shuttle mechanism are also presented. 1. A. Manthiram, Y.-Z. Fu, S.-H. Chung, C. Zu, and Y.-S. Su, Chemical Reviews, 2014, 114, 11751-11787. 2. M.-K. Song, E. J. Cairns, and Y. Zhang, Nanoscale, 2013, 5, 2186–204. 3. N. A. Cañas, K. Hirose, B. Pascucci, N. Wagner, K. A. Friedrich, R. Hiesgen, Electrochim. Acta, 2013, 97, 42–51. 4. N. A. Cañas, S. Wolf, N. Wagner, K. A. Friedrich, J. of Power Sources, 2013, 226, 313–319. 5. N. A. Cañas, D. N. Fronczek, N. Wagner, A. Latz, K. A. Friedrich, J. Phys. Chem. C, 2014, 118, 12106–12114. 6. N. A. Cañas, A. L. P. Baltazar, M. A. P. Morais, T. O. Freitag, N. Wagner, K. A. Friedrich. Electrochimica Acta, 2015, 157, 351–358. 7. D. N. Fronczek, W. G. Bessler. J. of Power Sources, 2013, 214, 183–188. 8. A. F. Hofmann, D.N. Fronczek, W. G. Bessler. J. of Power Sources, 2014, 259, 300–310.