Converging TechnologiesRenewable Energy

Tesla & Maxwell Battery – A Dazzling Combination for 2021?

Vehicle Batteries & Capacitors for convenient charging

Tesla is Poised to Dominate Vehicle Batteries

Tesla is poised to seriously dominate the EV market through the introduction of proprietary super efficient vehicle batteries.  SolarCity can tap the new designs and allow the reduction of cost together with efficiency gains.  Will they do it?   In this article we breakdown the technologies involved and the effects on your decisions around the choice of battery provider.

In 2017 Tesla, through its subsidiary SolarCity, began production of solar cells and modules at Gigafactory2 in Buffalo, NY.  On their Website, they have stated that they have begun production of components for a supercharger (no, not the combustion engine type of supercharger!) and ‘energy storage products’.

Why a Supercharger? And what’s in it for SolarCity (AKA Tesla)?

In his biography of Elon Musk, Ashlee Vance described Musk’s in-depth fascination with ultracapacitors that Tesla Solar Roofbegan while he studied at Queens University (Canada) and U Penn for his economics and physics degrees.  So when Tesla acquired Maxwell Technologies early in 2019, it was with a great big dose of strategic thought.  Please forgive me as I go around the bushes to cover the background on this.

Tesla makes cars as a vertically integrated company.  To have subcontracted any component to a subcontractor would have meant waiting in line behind GM, Ford, etc. for parts.  Disrupting the Tesla production line would have been a company killer, so they did not do that. But there is one sort of, almost exception. Panasonic is a battery company whose (presumably) proprietary manufacturing process is used onsite at Tesla Gigafactory1 to produce batteries which then cross the floor to be incorporated into Tesla vehicles.

Batteries versus Ultracapacitors

Batteries deliver energy whereas ultracapacitors deliver power.  A battery can be used for loads on a consistent basis but they charge slowly.  Ultracapacitors charge rapidly and discharge very rapidly.  Maxwell’s patents around ultracapacitors are extremely useful to Tesla.  If some ratio of battery-to-ultracapacitor is architected, then a Tesla EV can be charged to, say, a 1/3 charge (good for 80 km) – faster than getting a tank of gas.  While the vehicle drives away the ultracapacitor bank discharges into the battery bank to equilibrium.  This process eliminates a significant barrier to EV uptake in the North American car market.

But That Ain’t the Best Part

Maxwell also has patents on a ‘dry process’ for battery manufacturing that can replace the wet process that is currently employed. The wet process involves spraying with a toxic solvent that has to be baked off. The process involves off-gassing and pollution, not to mention additional steps that add cost.  The Maxwell ‘dry process’ eliminates these steps and has a path to almost doubling the energy density within the battery.  Wow. Can you say ‘double my car’s range?  How about ‘keep it the same but reduce my battery and the car cost’?

So now Tesla has a patent to replace the Panasonic patented process.  Vertical integration will thus be completed with a battery/ultracapacitor architecture manufactured through a proprietary process.  And this architecture will require a supercharger to complete the enhanced customer recharging experience.

What about SolarCity?

Electric motors (of which there are many) require a much higher power on startup than they do for continuous operation.  Even your refrigerator or air conditioner falls into this category.  Currently, a         5 kW Powerwall can give you 7 kW but only for about 10-12 seconds. To cover power surges more completely would require significantly oversizing the battery bank. If some proportion of the next-gen Powerwall is comprised of ultracapacitors, then the 12 seconds referenced above becomes 5 or 10 minutes, depending on the ratio of capacitor-to-battery in this new Powerwall.

In this scenario, you could draw very heavy surge loads from the Powerwall and still be able to maintain regular loads. In other words, off-grid performance becomes much more feasible with a smaller battery footprint.  So, smaller battery, better performance? Remember the ‘dry process’ mentioned above?  Increasing the cycles a battery can go through in its lifetime is a huge benefit to battery economics. What’s the cost?  Well, their cost to manufacture goes down.  Will they pass on the benefits to the economics of battery deployment? Watch this space as the company announces its new offerings.

Next, let’s postulate about solid-state batteries built with an ultracapacitor component.  The battery size will be reduced and that will leave room for a larger capacitor.


At the beginning of this article, I stated that batteries are for energy, and capacitors are for power.  I could also have stated that capacitors, which have no chemical reliances, do not suffer loss in terms of performance if they are cold or just old.  And although research continues today, we can confidently say that a battery/capacitor architecture built using Tesla’s dry battery electrode process will last longer and perform better than the current crop of battery-only banks.

What do you think?  Are Tesla and SolarCity on to something significant here?  What about the competition?  What are other players up to?  Make a comment below – we’d love to know what you think.

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