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nanotimes News in Brief

Battery Storage // KIT Researchers Develop New Concept for Rechargeable Batteries

© Text: KIT

Maximilian Fichtner, Head of the Energy Storage Systems Group, and Dr. Munnangi Anji Reddy at the KIT Institute of Nanotechnology (INT), Germany.

A

Metal fluorides may be applied as conversion ma- terials in lithium-ion batteries. They also allow for lithium-free batteries with a fluoride-containing electrolyte, a metal anode, and metal fluoride catho- de, which reach a much better storage capacity and possess improved safety properties. Instead of the lithium cation, the fluoride anion takes over charge transfer. At the cathode and anode, a metal fluoride is formed or reduced.

“As several electrons per metal atom can be transfer- red, this concept allows to reach extraordinarily high energy densities – up to ten times as high as those of conventional lithium-ion batteries,” explains Dr. Maximilian Fichtner.

The KIT researchers are now working on the further development of material design and battery archi- tecture in order to improve the initial capacity and cyclic stability of the fluoride-ion battery. Another challenge lies in the further development of the elec- trolyte: The solid electrolyte applied so far is suited

completely new concept for secondary batteries based on metal fluorides was developed by Dr.

11-10 :: October 2011

Setup of the fluoride-ion battery: A fluoride-containing electrolyte separates the metal anode from the metal fluoride cathode. © KIT

for applications at elevated temperatures only. It is therefore aimed at finding a liquid electrolyte that is suited for use at room temperature.

M. Anji Reddy and M. Fichtner: Batteries based on fluoride shuttle, Journal of Materials Chemistry AOP, October 13, 2011, DOI: 10.1039/C1JM13535J: http://dx.doi.org/10.1039/C1JM13535J