Various methods and apparatus relating to three-dimensional battery structures and methods of manufacturing them are disclosed and claimed. In certain embodiments, a three-dimensional battery comprises a battery enclosure, and a first structural layer within the battery enclosure, where the first structural layer has a first surface, and a first plurality of conductive protrusions extend from the first surface. A first plurality of electrodes is located within the battery enclosure, where the first plurality of electrodes includes a plurality of cathodes and a plurality of anodes, and wherein the first plurality of electrodes includes a second plurality of electrodes selected from the first plurality of electrodes, each of the second plurality of electrodes being in contact with the outer surface of one of said first plurality of conductive protrusions. Some embodiments relate to processes of manufacturing energy storage devices with or without the use of a backbone structure or layer.