CARRIER ION LOADING OF SECONDARY BATTERIES UTILIZING AUXILIARY ELECTRODES

An auxiliary electrode includes a conductive layer having a first major surface in an X-Y plane, the conductive layer is electrically conductive and has a first surface area. The auxiliary electrode includes a first carrier ion supply layer and a second carrier ion supply layer, each carrier ion supply layer comprising a material that supplies carrier ions for an electrode of the secondary battery. The first carrier ion supply layer covers a first region of the first major surface of the conductive layer and the second carrier ion supply layer covers a second region of the first major surface of the conductive layer. The first and second regions are separated by a third region, the third region configured to be folded such that the first region and the second region are substantially parallel, and the third region is substantially perpendicular to the first and second regions in the folded configuration.