US Patent 7851083 Lithium ion secondary batteries

The present invention relates to lithium ion secondary batteries that have an enclosure with an electrode core compartment for holding the electrode core and a separate protection circuit compartment for holding the protection circuits, and terminal leads connecting the electrodes in the electrode core with the circuits in the protection circuit. The enclosure is made of non-conducting material such as plastic. The lithium batteries of this invention are light, not only because of the weight of the material of their enclosure, but also because its non-conducting character eliminates the necessity of additional protective features that are commonly necessary for enclosures with metal components.