CATL already has a plant in Germany, along with a $5 billion battery plant under construction in Indonesia and plans to make a similar investment in the US. Its own investments in both lithium and cobalt mining help insulate the company from fluctuations in commodity prices. But one of the key drivers for CATL’s global expansion will be cell-to-chassis technology, where the battery, chassis and underbody of an electric vehicle are integrated as one, completely eliminating the need for ‘a separate battery pack in the vehicle.
Redistributing the mass of the batteries will also free up space in a car’s design for a more spacious interior, as designers will no longer have to raise the ground height of an EV to store the cells below in a large slab. Freed from these previous limitations, since the cells can make up the entire chassis, manufacturers will be able to squeeze more cells into each EV, thus increasing the range.
CATL estimates that production vehicles of this design will achieve ranges of 1,000 kilometers (621 miles) per charge, 40 percent more than conventional battery technology.
At Tesla’s 2020 Battery Day, the company shared some key advancements. While Tesla’s new 4680 battery dominated the headlines, CEO Elon Musk and Senior Vice President Drew Baglino described how Tesla car production was changing by using large-scale castings to replace several smaller components. They also said that Tesla would start using the cell-to-body technology around 2023.
Using the analogy of an airplane wing, where now instead of having a wing with a fuel tank inside, the tanks are shaped like a wing: The duo said the battery cells would be integrated into the structure of a car. To do this, Tesla has developed a new glue. Typically, the glue in a battery pack holds the cells and plates of the pack together and acts as a fire retardant. Tesla’s solution adds a bracing feature for the adhesive, making the entire battery support the load.
McTurk explains: “The integration of cells into the chassis allows the cells and the chassis to become multipurpose. The cells become energy storage and structural support, while the chassis becomes structural support and cell protection. This effectively cancels out the weight of the cell shell, turning it from dead weight into something valuable to the vehicle structure.”
According to Tesla, this design, along with its die-casting, could allow vehicles to save 370 parts. This reduces body weight by 10 percent, lowers battery costs by 7 percent per kilowatt-hour, and improves vehicle range.
While Tesla’s larger-volume 4680 battery appears to play an integral role in the company’s ability to move to a cell-to-body design, CATL’s new Qilin battery boasts a 13-per percent of the capacity compared to the 4680, with a volume utilization efficiency of 72 percent and an energy density of up to 255 watt-hours per kilogram. It will become a key part of CATL’s third-generation cell-to-pack solution and will likely form the basis of the company’s cell-to-chassis offering.
An easy cell
For those who think that these innovative battery technologies are still a few years off, the cell-on-chassis is indeed here. Fast-growing but still relatively unknown Chinese electric vehicle startup Leapmotor claims to be the first company to bring a production car with cell-to-chassis technology to market. Leap’s C01 sedan should go on sale before the end of 2022. Using proprietary technology, which the company has offered to share for free, Leap says the C01 offers superior handling (the best weight distribution of the designs cell to chassis could explain it). ), a slightly longer range and improved crash safety.
Many electric vehicles were previously built from internal combustion car platforms, and some still are, but the adoption of cell-to-chassis designs will render these older platforms hopelessly obsolete. According to Frost at Sprint Power, “the commitment of the majority [manufacturers] to an EV-only future together with more integrated designs such as cell-to-chassis will lead to significant improvements in overall EV design and performance.”
While cell-to-chassis technology is certainly the next step with electric vehicles, it’s not a panacea. Technologies such as solid-state batteries and sodium-based batteries are likely part of the puzzle. And cell-to-chassis adoption will undoubtedly introduce new challenges for the industry.
For one thing, replacing faulty cells will be much more difficult in a cell-to-chassis shell, since each cell will be an integral part of the car’s structure. Then there is the question of what happens when the car is scrapped. Currently, the modules can find their way into many second-life applications, but McTurk believes that larger battery sizes in cell-to-pack and cell-to-chassis designs may limit them to storage applications in network