A team of researchers examining batteries from Tesla and BYD discovered an unexpected absence of silicon in the anodes, challenging assumptions about improving energy density in electric vehicles. The study, published in Cell Reports Physical Science, compared Tesla's 4680 cylindrical cell with BYD's Blade prismatic cell, revealing key differences in design and performance. These findings offer rare insights into the inner workings of leading EV battery technologies.
Researchers have gained new understanding of electric vehicle battery designs by dissecting cells from two major manufacturers, Tesla and BYD. The analysis, detailed in a study published in Cell Reports Physical Science, focused on Tesla's 4680 cylindrical battery and BYD's Blade prismatic lithium iron phosphate battery. This examination is among the first to provide in-depth data on such advanced automotive batteries.
The Tesla battery emphasizes power and range through a higher energy density in a compact form, making it suitable for high-performance and luxury vehicles. However, this design increases production costs and can lead to greater heat buildup, potentially complicating fast charging and reducing lifespan. In contrast, the BYD battery prioritizes stability, safety, longevity, and affordability, with features that make it more resistant to thermal runaway— a common safety concern in batteries. These attributes position it well for mass-market and budget-friendly EV models.
A notable surprise emerged in the materials: neither battery contained silicon in the anodes. "We were surprised to find no silicon content in the anodes of either cell, especially in Tesla's cell, as silicon is widely regarded in research as a key material for increasing energy density," said lead author Jonas Gorsch in a news release.
The study highlights significant mechanical, electrical, and material differences between the cells. As Gorsch noted, "There is very limited in-depth data and analysis available on state-of-the-art batteries for automotive applications." The researchers' report states: "This article provides insights into the design and characteristics of state-of-the-art LIBs for automotive applications. The comparative analysis of the Tesla 4680 cylindrical cell and the BYD Blade prismatic cell highlighted significant mechanical, electrical, and material differences that could influence future cell design iterations."
Electric vehicles play a crucial role in reducing pollution and transitioning to cleaner energy, with lower long-term operating costs compared to traditional cars.