This title appears in the Scientific Report : 2014 

Prospects and aspects of advanced Lithium-ion and post-Lithium electrochemical cells for high-performance energy-storage applications
Eichel, Rüdiger-A. (Corresponding Author)
Grundlagen der Elektrochemie; IEK-9
2014
2014
6th Interantional Symposium on Functional Materials, Singapore (Republic of Singapore), 2014-08-04 - 2014-08-07
Conference Presentation
Renewable Energies
Lithium-ion battery technology currently provides the best compromise between high power- and enhanced energy-density. In order to attain high rate capabilities, simulta-neous high electronic and ionic conductivity has to be achieved for the active material, for which reason nano-scaled materials are typically used. Tailoring the charge-transport properties in terms of aliovalent doping, however, provides an alternative approach with less complicated processing. By systematically introducing defects to the material, lattice vacancies and donor-type inter-band states might be formed that corre-spond in the desired properties. However, at high charge/discharge rates, dendrite growth might impose serious degradation and safety issues at the anode side. By em-ploying dedicated 'in-operando' spectroscopy methods, the growth of dendrites might already be monitored at an early stage, thus providing a technique to effectively investi-gate the impact of various additives for organic-based electrolytes to inhibit the dendrite growth.Cyclic aging is still a limiting factor in current Lithium-ion technology. The correspond-ing mechanisms extend of multiple scales. At the atomic scale, anti-site diffusion and formation of side reactions owing to the limited stability of currently available organic-based electrolytes, define two of the most recent processes. The corresponding mecha-nisms are unraveled at an atomic scale by employing dedicated techniques of magnetic resonance.Whereas with advanced Lithium-ion technologies, only moderate evolutionary advances can be achieved, 'post Lithium-ion' concepts offer the potential of substantial revolutionary pro-gress. In that respect, Li-O2 cells offer the highest theoretical energy density. However, extensive side reactions and decomposition of organic-based electrolytes at the oxygen-reduction catalyst, limit the cyclic efficiency and lifetime. As a promising alternative, 'post-Lithium' metal-air electrochemistry based on supervalent ionic concepts, such as divalent Zn-O2, trivalent Al-O2 and Fe-O2, as well as tetravalent Si-O2 cells come into play. Current technology, however, is mainly hampered by accelerated cyclic aging and limited stability / charge-transfer properties of the available electrolytes.