Fixed with a click
Photovoltaic plants, electric bicycles or wireless power tools require energy stores, for example in the shape of batteries or accumulators. Often, the individual storage cells are combined as modules the size of which depends on the respectively required storage capacity.
State of the art
Typically, the individual accumulator cells are shaped like cylinders with a diameter of a couple of centimetres. Often, six to eight of these storage cells are put in a flat plastic holder, while an identical holder is placed on the cylinders as a lid. Thin metal rails that are about half a centimetre wide provide an electrically conducting link between the accumulator cells. These rails are loosely placed in spaces in the plastic holders and afterwards welded together with the accumulator cells. In order to prevent the rails from slipping during the welding process, they are often first stuck firm. While sticking them raises the production effort, it also reduces the risk of producing faulty storage modules.
Researchers at the KIT Battery Technical Center have found a way of reliably preventing the electricity-conducting rails from slipping without sticking them. For this purpose, they have supplemented the design of the plastic holders with protrusions shaped like little noses. These noses are made of thin, elastic plastic and protrude a little into the spaces provides for the metal rails. In this manner, the rails can be clicked into the spaces and are thus already firmly fixed during the production process.
This method reduces rejects that may be created when the rails slip. In addition, the holder lowers the production effort and allows the electric rails to be simultaneously welded on the top and bottom sides. The holder, which can be cheaply manufactured using the blow-moulding method, is also designed to accommodate two electric rails, one on top of the other, and therefore provides the option to link up several storage modules.
Options for companies
The KIT scientists have successfully tested the holder in a semi-automated production process and are now looking for partners to apply the technology.
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