Arguably, there are two leaders in the electric vehicle world: Tesla, which is run by Elon Musk and headquartered in Austin, Texas; and BYD, a Chinese carmaker that’s racking up huge sales around the world. Not surprisingly, each of these manufacturers takes a slightly different approach to designing, engineering, and manufacturing EVs, and this, of course, extends to their battery pack configurations.
NMC Vs. LFP, Round Cells Vs. Blades
According to an article published by SciTechDaily.com, researchers at Cell Reports Physical Science have analyzed the batteries used by both Tesla and BYD, and they found some intriguing differences between the two. In short, Tesla’s 4680 cells, which feature a nickel-manganese-cobalt chemistry (NMC), are designed for performance and high energy density. This contrasts with BYD’s blade design, which implements more cost-effective materials (a lithium-iron-phosphate chemistry, LFP for short) and emphasizes space efficiency.
These approaches are two different ways of reaching the same destination, though interestingly, BYD’s battery configuration has better thermal management. Reportedly, Tesla’s offering produces around twice as much heat at a specific load than BYD’s configuration. This difference requires, not surprisingly, around twice as much cooling capacity.
Additionally, BYD’s electrodes incorporate two welding technologies, ultrasonic and laser. As the Cell Reports Physical Science article notes, “The advantage of this approach is that laser welding only needs accessibility to the busbar from one side, and the ultrasonic welds ensure layer-to-layer contact in preparation for laser welding.” Additionally, “This allows for a very space-efficient contacting design where the contacting itself only takes the space of one electrode foil stack fold.” In comparison, “The Tesla 4680 cell electrode/contacting foil edges (anode and cathode) are slit at an angle, and then folded onto another, creating a contacting surface,” a tab-less design.
When it comes to energy density, Tesla handily wins in this category, which is no surprise since the 4680 cell uses a powerful NMC chemistry. These batteries achieve an energy density of around 241 Watt-hours per kilogram of mass on the cell level. The BYD design, in comparison, is rated at just 160 Wh/kg. Both designs, however, “utilize graphite anodes without silicon dioxide.”
Subtle But Substantive Differences
They may all seem pretty similar, but electric vehicles can have some wildly different engineering characteristics. Battery chemistry and configuration can dramatically change how an EV performs, with different design decisions providing unique tradeoffs. This is no different from with traditional internal-combustion engines, though the vagaries are not as obvious as they are with, say, an overhead cam engine, like Ford’s 5.0-liter Coyote V8, and GM’s pushrod LT family. Both designs produce loads of power, but their internal designs – and myriad other factors – are radically different. The same happens in the EV world, it’s just far subtler than fire-breathing V8s.
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