Service Communautaire d'Information sur la Recherche et le Développement - CORDIS

Development of lightweight lead-acid batteries (LWLB) for electrical and conventional vehicles

Advanced lightweight lead-acid batteries are being developed using new innovative materials and process techniques. Research has been carried out in order to substitute the heavy lead alloy grids (mechanical support of the active masses and collectors of the current produced during the charge and discharge reactions) by lightweight metallized polymeric network structures (PNS) with reduced mesh dimensions in comparison to conventional grids. The network is then coated with conductive materials and corrosion resistant lead layers to conduct the current flow.

A design has been developed for a continuously processed, thermally shaped, open-mesh network structure of co-knitted multi-component polyester fibres and copper filaments, to be used as lightweight electrode grid in lead-acid batteries. The inclusion of copper filaments at the knitting step yields a good electrical conductivity across the grid, thus allowing a fast processing at the subsequently performed galvanic metal coating. In order to metallize polymer grids by electrochemical plating, conducting starting layers have been provided by coatings of carbonaceous materials. This new process is characterized by a simple dip coating of the polymer grids in a carbon paste with an additional surface treatment by a graphite finish process, and replaces conventional electroless methods for metallizing plastics with advantages of simple processing and machining, possible continuous processing, short process times, reliability and the use of relatively cheap and environmentally friendly materials. A continuous process has been developed for the carbon coating, surface treatment and reinforcement of the conductive starting layer by electroplating, characterized by a material selective pre-cutting of the electrodes out of the continuous PNS-band, leaving the uncut copper filaments in the continuous band. This mechanical support of the electrodes is a big improvement for transporting, contacting and mechanical stability during the whole process.

Contact

María-Luisa SORIA
Tél.: +34-949-263316
Fax: +34-949-262560
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