Tesla introduced its new structural battery pack along with its new 4680 battery cells in September of last year during its Battery Day event. The new structural pack acts as a body that links the front and rear underbody parts. The new cells have a tabless design that will decrease the time of charging. In addition, the new form factor of the cell makes it six times more powerful with up to five times the energy capacity than the company’s previous cells. Given its name, Tesla also confirmed the new cell is 46mm by 80mm.
Tesla’s current battery packs are built by combining cells into modules and then combined to form a battery pack which is then installed into the vehicle platform. The new concept will eliminate the modules and built the entire pack as the vehicles structural platform using battery cells to form an individual unit. Tesla will connect a large single-piece rear and front underbody to the structural battery pack using giant casting parts.
The new structural design improves the efficiency of Tesla vehicles by reducing the number of parts as well as the total mass of the battery pack. It is expected to be installed in the Model Y produced at Tesla Giga Berlin and in the upcoming Model S Plaid.
The structural advantages seen in the honeycomb structure have been utilized not only in the auto industry but in the aerospace industry as well. However, this is the first time it has been seen used for this particular function. For example, the BMW i3 currently uses a hexagonal honeycomb structure around the vehicle’s battery pack for crash absorption.
The honeycomb structure will eventually be combined with Tesla’s new 4680 battery cells which will be put into the empty slots and then bound to the pack to provide not only power to the vehicle, but to play an integral part in the vehicle’s structural integrity.
According to Tesla CEO Elon Musk, the “battery pack will be a bonded structure with cells providing shear transfer between steel upper & lower face sheets, eliminating most of the center body parts while providing better torsional rigidity & improved polar moment or inertia. This is a major breakthrough.”