Here come “structural” batteries
This is a mock-up of a battery concept by Cape Bouvard Technologies in Mosman Park, Wash. of what the 
company calls a structural battery. The battery structure incorporates high-strength composites that let the battery structure add stiffness to the vehicle chassis holding it. This idea, in turn, can lead to some weight reduction in the vehicle structural components. There are channels built into the composites that evacuate any gases from the batteries and can deliver coolant if need be. The batteries on board, typically 18650 or 21700 cylindrical cells, connect together via a lightweight busbar.
The cells can be assembled into a number of series and parallel configurations resulting in a wide variety of voltage and amperage as necessary. For full details, go to the Rolled-Ribbon Battery Company website http://www.rolled-ribbon.com