Environmentally compatible electricity storage systems
Accumulators, e.g. for electric vehicles, should be as small and light as possible. At the same time, they have to reliably provide high currents and voltages. Some of today’s storage systems ensure a high energy density, but have the drawback that the materials used are expensive or not environmentally friendly.
State of the art
Hence, KIT researchers working at the Institute for Applied Materials – Energy Storage Systems (IAM-ESS) look for technological alternatives, in particular as regards the composition and manufacture of electrodes. Today, the negative electrode (anode) is frequently made of graphite, while the positive electrode (cathode) consists of various metal-containing materials. The metals contained in the cathode material are responsible for electricity production by electron acceptance (reduction) and electron release (oxidation). Highly efficient accumulators use metals that can be reduced and re-oxidized in two steps and, hence, supply two electrons per reaction. During discharge, these electrons flow from the anode to the cathode. For charge balance, the cathode material must be able to intercalate positive lithium ions. The performance of an accumulator, hence, is also determined by the lithium intercalation capacity.
The cathode materials studied at KIT consist of lithium and a transition metal oxide. In particular, iron, manganese, titanium, and vanadium are applied, as these materials are suited for two-electron reactions. Compared to nickel and cobalt that have been used widely so far, these metals are less toxic and available at reduced costs.
The newly developed cathode materials also are capable of intercalating more than one lithium ion per formula unit on the average. The KIT-developed cathode materials, hence, are characterized by a high energy density. The materials are environmentally compatible, long-lived, and can be produced at low costs. Hence, they are suited for use in larger accumulators in e.g. electric vehicles or stationary energy storage systems.
Options for companies
KIT looks for partners to use this technology in practice.
Your contact person for this offer
Dr. Aude Pélisson-Schecker,
Karlsruhe Institute of Technology (KIT)
Innovation Manager Energy, Innovation and Relations Management (IRM)
Phone: +49 721 608-25335