Over the years, rechargeable battery technology has grown only by short spurts, intervening time typified by stagnation, but that has not stopped innovators, such as Elon Musk, from making other improvements to the technology.
We cover many new battery technologies on this site, such as Sakti3 solid-state lithium-ion cells and Envia Systems’ 400 Wh/kg cells, both of which promise a lot, but have yet to deliver. Still, while a high-capacity reliable rechargeable battery is still forever on the horizon, this does not mean that there is little innovation left in the application of existing technologies. For this, engineers turn to improving efficiency. Last year, for example, Yaskawa Electric developed an electric motor-generator with 30% more windings, developing 30% more power, in theory, simply by changing the shape of the wire.
Could Elon Musk do something similar with rechargeable batteries in the Tesla gigafactory? As we know, the purpose of the Tesla gigafactory is to force lithium-ion battery prices down by mass-producing the cells. By 2020, when the plant is set for full production, it should produce annually the same amount of cells that all of today’s producers do, including Panasonic, Tesla Motors’ current supplier. In fact, Panasonic is expected to put in around $1 billion once all is said and done, to be the sole producer of lithium-ion cells in the plant. Still, sticking with the current Panasonic 18650 cell is not going to fly.
Elon Musk figures that the cells can be made better, especially if designed specifically for placement in a Tesla battery pack. Originally, Tesla Motors chose the Panasonic 18650 simply because it was a commodity cell with the right characteristics, including energy density, reliability, size, and price, since it is produced in the millions. Because it is cylindrical in shape, however, it is hardly ideal for placement in a battery pack.
It is interesting to note that Tesla Motors’ Elon Musk and Panasonic, are working on at least two fronts in electric vehicle battery packs. First, Musk does seem to be interested in graphene’s possible application to improve energy density. Second, the two companies are working together to optimize the size and shape of individual cells, to improve the effective energy density of the Tesla Motors battery pack.