BYD vs Tesla: Researchers Reveal Which EV Battery Reigns Supreme

The battle for EV battery supremacy just took an interesting turn. German researchers have torn down and meticulously analysed batteries from two of the biggest names in electric vehicles—Tesla and BYD. Their conclusion is that:

• BYD’s Blade battery is more efficient largely due to its superior thermal management and cost-effective materials.
• Tesla’s highly-touted 4680 cell has higher energy density and better raw performance.

The findings, published in Cell Reports Physical Science, come from a team at RWTH Aachen University in Germany, who went deep under the hood to dissect these two leading battery technologies. Their analysis covered everything from mechanical design and electrode materials to energy density and efficiency.

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Tesla vs BYD: A Tale of Two Approaches

When it comes to battery design, Tesla and BYD have taken distinctly different paths. Tesla prioritises energy density and raw performance, while BYD leans towards volume efficiency and affordability. That means Tesla’s 4680 battery, with its NMC811 chemistry, delivers a high energy density of 241.01Wh/kg and 643.3Wh/l. Meanwhile, using lithium iron phosphate (LFP) chemistry, BYD's Blade battery comes in at 160Wh/kg and 355.26Wh/l.

But numbers don’t tell the whole story. While Tesla’s battery can pack in more energy per unit, BYD’s prismatic cell format allows for better space utilisation and heat dissipation, crucial factors in an EV's real-world performance. Better thermal management means a more stable battery, reducing the risk of overheating and extending the lifespan of the pack. That’s a major win for reliability, especially in hot climates like Australia.

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The Surprising Battery Breakdown

One unexpected discovery? Neither Tesla nor BYD use silicon in their anodes, despite silicon being widely recognised for boosting energy density.This caught lead researcher Jonas Gorsch off guard, particularly in Tesla’s case.

“We were surprised to find no silicon content in the anodes of either cell,” said Gorsuch, who specializes in the Production Engineering of E-Mobility Components. “Silicon is widely regarded in research as a key material for increasing energy density.”

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Beyond chemistry, the two companies also differ in cell structure. Tesla’s 4680 cell is cylindrical, while BYD’s Blade battery is a prismatic design. The result? A major contrast in volume efficiency. Despite BYD’s cell being larger, the proportion of passive components (like housing and busbars) remains nearly identical between the two.

Interestingly, both companies use advanced welding techniques to connect their thin electrode foils. Tesla opts for laser welding, while BYD uses a mix of laser and ultrasonic welding. The latter approach is less common in the industry, hinting at BYD’s push for innovation.

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What This Means for EV Buyers in Australia

For Aussie EV buyers, these findings reinforce why BYD’s affordable EVs, like the Dolphin and Atto 3, are gaining in popularity. The Blade battery’s LFP chemistry means better durability, lower costs, and reduced risk of thermal runaway (aka battery fires). That’s a big plus for Australian conditions, where scorching summers can test battery resilience.

Tesla, on the other hand, still leads in energy density and performance, making its cars appealing to those prioritizing range and power.But with BYD undercutting Tesla on price, offering solid efficiency, and expanding into global markets at breakneck speed, the competition is heating up.

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Zecar's Take

While Tesla’s 4680 battery is a powerhouse in terms of energy density, BYD’s Blade battery stands out for its efficiency, cost-effectiveness, and superior thermal management. As the EV market evolves, both approaches have their merits. But for everyday drivers looking for a reliable, cost-effective EV, BYD’s battery technology might just have the edge.

With BYD aggressively expanding into Australia and its tech continuing to impress, Tesla may need more than just brand appeal to maintain its stronghold.