Xiaomi Auto’s “Kirin Battery”? Ningde Era Revealed

According to news on February 20, as Xiaomi cars are about to be mass-produced and launched, the CATL batteries they are equipped with have also attracted attention from the outside world. On February 18, in a video officially released by CATL, its engineers revealed   the special features of the Xiaomi SU7 ( parameters | inquiry ) battery that improves cruising range and ensures safety - the cell pressure relief valve and poles are inverted at the same time. .

According to an engineer from CATL, “Most electric vehicle battery packs on the market have batteries placed upright, with poles and pressure relief valves facing upwards. A few use CTP3.0 technology (module-less battery packs). For models, the pressure relief valve is inverted to achieve thermal and electrical separation to ensure the safety of the vehicle occupants when the battery thermal runaway occurs."

The CTB technology adopted by Xiaomi Auto this time is considered to be a further step forward from CTP3.0.

As Xiaomi's first model, Xiaomi SU7 is positioned as a C-class high-performance ecological technology sedan, benchmarking against the BMW 5 Series. The dual-motor version has a maximum power of 673 horsepower, can accelerate to 100 kilometers in 2.78 seconds, and is equipped with a CATL Kirin battery with a capacity of 101kWh. , CLTC cruising range is 800km.

At the press conference, Lei Jun emphasized, "The battery is the cornerstone and core component of pure electric vehicles. Its cost accounts for 40% to 50% of the entire vehicle, and it affects the vehicle's endurance, safety, and control."

On the one hand, Xiaomi's battery pack wiring harness has been reduced by 91%, which ultimately makes the battery pack highly integrated with a volume efficiency of 77.8%, giving the car a higher cruising range.

On the other hand, when the battery core undergoes thermal runaway, the high-temperature and high-pressure gas generated inside the battery core will be discharged downward and out from the bottom of the vehicle through the exhaust channel to avoid causing harm to the occupants in the vehicle. In extreme cases, toxic fumes are also discharged to the outside of the vehicle through the bottom, ensuring the safety of the passenger compartment to the greatest extent. This is also an important reason why CATL’s CTB technology uses the battery poles and pressure relief valves to be inverted at the same time.

It is worth noting that the inversion of the battery cells on Xiaomi cars this time is not a simple upside-down structure, but a comprehensive redesign of the structure, process and conductive materials.

First of all, Xiaomi specially developed a lower conductivity coolant. The conductivity is only 1/40 of traditional coolant. By increasing the short-circuit resistance, thereby reducing the temperature rise, the battery system can be continuously immersed without causing a sharp temperature rise. short circuit.

Secondly, researchers from Xiaomi and CATL have customized high-temperature macromolecular electrolytes, using aviation-grade corrosion-resistant materials. The working temperature is 10-15°C higher than traditional electrolytes. The super temperature tolerance not only solves the soaking problem, but also increases the overall service life of the battery core to more than 15 years.

Based on this, Lei Jun said bluntly, "It is impossible for such a car to cost 99,000 yuan, and it is impossible to cost 149,000 yuan. Anyone with this kind of performance and configuration will cost more than 400,000 yuan."

In Lei Jun's view, "Xiaomi Motors will become one of the top five automakers in the world through 15 to 20 years of hard work." His goal is to rival Porsche and Tesla and create a "dream car" for the new era of the automotive industry.