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BYD’s hexagonal prism battery and potential advantages

Source: Auto Science Island


Just two years after the launch of the blade battery, news came: On January 30, BYD’s hexagonal prism battery came out.

Previously, in August 2022, BYD announced the types of new battery patents, and the hexagonal prism battery was invented in response to the trend. Judging from the published patent drawings, this new type of battery is very different from the common square batteries and cylindrical batteries, and the single cell of this battery is in the shape of a hexagonal column, which is believed to have obtained bionics inspiration from the honeycomb structure — the biggest advantage of this design is that it is more conducive to the tight fit between the batteries and improves the space utilization and energy density of the battery pack.

In fact, starting from the blade battery is to find room for improvement in the internal physical structure of the battery, thereby improving energy density and utilization. This time, BYD seems to start from the physical structure again, “squeezing” a higher performance utilization.

According to the data on the patent, the height of the entire casing (cover + casing) is between 60 and 150mm. The diameter of the inscribed circle of the shell is between 15mm and 60mm. It is worth mentioning that the patent also mentions: “The height of the shell can be 90mm, and the diameter of the inscribed circle can be 40mm”, and according to the naming rules of the battery, this battery can be called “4090 battery”. For reference, the Tesla 4680 battery measures 80mm in height and 46mm in diameter. Therefore, compared with Tesla’s 4680 battery, BYD’s hexagonal prism battery will appear “tall and thin”.

Comparison between BYD 4090 battery and Tesla 4680 battery

First, about the similarities, both 4090 and 4680 batteries adopt CPC technology, that is, the module-free solution. The entire battery pack is full of batteries without a well-shaped basic frame. The battery uses side heat dissipation, the efficiency is relatively high, and the performance is better



Next, about the differences, with respect to structural strength, when 4680 cylindrical cells are combined together, the space between two adjacent cylindrical cells is large, which will influence the mechanical stability of the cylindrical battery pack. Vibration or impact may cause short circuit or damage, affecting the safety of the vehicle. But, the hexagonal prism “4090 battery” forms a honeycomb shape after being grouped. There are no gaps between battery cells, thus improving the structural strength of the battery pack.

In addition, it is reported that the shell material of the hexagonal prism “4090 battery” may be made of aluminum alloy. This can not only ensure the strength of the power battery, but also reduce the weight of the battery pack. The significance of this high-strength battery pack is not only in terms of safety, but it may also be the future development trend of BYD.

Further, due to the hexagonal structure, there is more space inside than a circle. Therefore, the “4090 battery” with a hexagonal prism can accommodate more electrolyte to prolong the service life of the pole core. At the same time, when connecting multiple batteries into a battery module, it also effectively improves the space utilization.