Tesla Motors’ hybrid battery pack for ultra-long-range electric vehicles

Tesla Motors recently filed for a patent on a hybrid battery pack design that enables joining metal-air and lithium-ion battery cells into one battery pack, to implement a much larger total energy capacity and therefore a longer driving range.  The idea is “just” a patent at this moment, and metal-air batteries aren’t available in automotive-quality cells yet, but it shows that Tesla is looking into the future.  And, for that matter, I’m sure the other automakers are looking into similar ideas.

The point is to take advantage of the huge energy capacity gain benefits of the metal-air batteries.  This is technologies like zinc-air, aluminum-air, magnesium-air, iron-air, lithium-air or
vanadium-air batteries, all of which have researchers attempting to develop batteries using those chemistries.  In each case the “-air” part means that part of the battery construction uses oxygen from the atmosphere.

 

That’s a block diagram of the battery pack and the energy flows within the system.

The lithium-air portion of the battery pack is used to power the drive system, because lithium-ion is more capable of the power levels required to do so.  Metal-air batteries, while they have high energy density do not support high charge/discharge rates.  In this design the metal-air portion is used solely to keep the lithium-ion pack charged up.

For more details see the patent application.

About David Herron

David Herron is a writer and software engineer living in Silicon Valley. He primarily writes about electric vehicles, clean energy systems, climate change, peak oil and related issues. When not writing he indulges in software projects and is sometimes employed as a software engineer. David has written for sites like PlugInCars and TorqueNews, and worked for companies like Sun Microsystems and Yahoo.

About David Herron

David Herron is a writer and software engineer living in Silicon Valley. He primarily writes about electric vehicles, clean energy systems, climate change, peak oil and related issues. When not writing he indulges in software projects and is sometimes employed as a software engineer. David has written for sites like PlugInCars and TorqueNews, and worked for companies like Sun Microsystems and Yahoo.

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