Researchers from RWTH Aachen University in Germany have taken apart and analysed two of the most widely used electric car batteries: Tesla’s large cylindrical cell from the 2022 Model Y made in Texas, and BYD’s flat cell found in cars like the Han and Dolphin.
They found that Tesla’s battery stores significantly more energy, about one and a half times more by weight and nearly twice as much for the same volume. However, this comes at the cost of increased heat generation: at a standard discharge rate, the Tesla cell produces 2.3 times more heat per volume. One of the most surprising findings is that neither battery uses silicon anodes, even though silicon is often seen as a key upgrade for future batteries.
Overall it seems that Tesla aims at performance first, whereas BYD simplifies for ease of production and cost.