Has Tesla Motors quietly improved its battery technology?

Better battery technology is often referred to as the "holy grail" necessary for electric vehicles to truly disrupt the world's addiction to gas-powered cars. Is Tesla quietly making advances on this front? To better understand the situation, it's best to rewind back to this summer. According to Charged Magazine*, during a conference call in July announcing “ludicrous" mode, Tesla Motors CEO Elon Musk revealed something else intriguing -- he hinted a bit more about an increase in energy density of the cells in the new 90 kWh pack. During the conference call, Musk told reporters that “it is, actually, as a result of improved cell chemistry. We’re shifting the cell chemistry for the upgraded pack to partially use silicon in the anode. This is just sort of a baby step in the direction of using silicon in the anode. We’re still primarily using synthetic graphite, but over time we’ll be using increasing amounts of silicon in the anode.”

Source: Tesla Motors

Awe-struck by Tesla's new “ludicrous” speed, the media mostly dismissed (or missed) Musk's comment about improved battery cell chemistry. However, introducing silicon into automotive-grade lithium-ion cells represents a huge milestone for the EV (electric vehicle) industry. Silicon is widely considered to be the next big thing in anode technology, because it has a theoretical charge capacity ten times higher than that of typical graphite anodes. “It’s a race among the battery makers to get more and more silicon in,” explains Jeff Dahn, a world-renowed battery researcher. Unlocking the potential of silicon could give a company the edge needed to become an early leader in advanced battery technology.  So it’s no surprise that, as Jeff Dahn elaborated, “the number of researchers around the world working on silicon for lithium-ion cells is mind-boggling.” 

Image: Charged Magazine*

Quartz also weighed in, noting that Musk "didn’t mention that, for the automobile industry, Tesla’s use of silicon is no small thing—indeed it’s a first. While battery researchers around the world have attempted the feat for years, until now no one has managed to put the potent but rambunctious element [silicon] into a working vehicle battery... It’s a mystery as to why Musk—extraordinarily vigilant and purposeful when it comes to his public image, and not one to shy from a chance to boast—passed up an opportunity to flag a scientific coup. Tesla didn’t respond to an email on this issue; in response to an earlier query regarding how much silicon the anode contains, a spokeswoman declined to add to Musk’s remarks in the call."

Hmmmm. But, wait… let's backtrack, who exactly was that guy, Jeff Dahn? Well, this summer the Wall Street Journal reported, "Tesla Motors Inc. has locked a leading advanced battery researcher into an exclusive partnership… Jeff Dahn, a professor at Dalhousie University in Nova Scotia known for his work innovating lithium-ion batteries like those Tesla uses to power its Model S sedan, will cooperate with Tesla researchers. Now working on a project with 3M Co., he will enter a research partnership with Tesla when his current work is completed. [Dahn] patented a nickel-cobalt-manganese chemistry for battery cathodes that is now commonly used in the industry. He is also the leading researcher on why lithium-ion batteries fail… [and] one of his areas of expertise is silicon anodes."

Source: Dalhousie University; Above: Jeff Dahn (drivers seat) takes a Tesla Model S for a spin after signing a research agreement with Tesla Motors.

Okay, so partnering with Dahn is definitely a big deal for Tesla Motors. But, has Tesla improved its underlying battery technology? Let's fast forward to this week. Tesla CEO Elon Musk was interviewed on stage for this year’s Presidential Forum at the American Geophysical Union (AGU) Fall Meeting in San Francisco. Much of the interview revolved around Musk’s pioneering work at SpaceX and views on renewable energy. However, after a Tesla-related battery question arose from an audience member, Musk confessed, “There will be moderate improvements, in the underlying technology — not giant, not small, but kind of medium. Then, over time I would expect those technologies to get better and better… it usually ends up being, on average, about a 5 to 8% improvement per year in energy density.” Take a look at the clip below…

Elon Musk usually focuses on "economies of scale" as the Gigafactory's key lever for improving battery costs — yet "Musk has always played down the prospect for big battery advances" according to Quartz. In our "Battery Costs Falling" blog series (Part 1 and Part 2), we've discussed the likelihood that Tesla's Gigafactory will result in substantive cost-cutting. Nevertheless, in most interviews, Musk typically shies away from any discussion about battery technology improvements. That said, it sounds as if Musk, during his AGU interview, is hinting at some “medium” improvement in battery technology at Tesla Motors. If so, we can’t wait to hear more about it. We'll keep you posted as more surfaces about this...

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*Source: Charged Magazine / Video: Maziyar Boustani (AGU)