Recently, CATL officially released the 3rd-gen CTP (Cell to Pack, no-module power battery pack) technology – Qilin battery. Through structural optimization, the volume utilization rate of the Qilin battery’s battery pack is increased to 72% (the volume utilization rate of the Tesla 4680 battery is about 63%), and the energy density of the ternary lithium battery system can reach 255Wh/kg (About 13% higher than Tesla 4680 battery), which can easily allow electric vehicles to achieve 1000km battery range, and it can support 4C charging rate. The Qilin battery will be mass-produced in 2023. Li Xiang, the founder of Lixiang Auto, also interacted with CATL on Weibo.com and said “see you next year”, which seems to indicate that Lixiang’s coming models will be equipped with the battery.
In 2019, CATL released the 1st-gen CTP technology, which eliminated the module level in the “cell-module-whole pack” battery architecture, increasing the volume utilization rate of the battery pack to 55%. Improving the energy density of battery packs through structural innovation, it has also become an important means to improve vehicle battery life. BYD blade battery and CTB technology, Tesla 4680 battery, and Leapmotor CTC technology all belong to this type of solution.
The main upgrade of Qilin battery is in structure. It integrates the independent transverse beams, water cooling plates and thermal insulation pads in the battery pack into a multi-functional elastic sandwich, which further improves the “available space” inside the battery pack. At the same time, a micro-bridge connection device is built in the multi-functional elastic interlayer, which can freely expand and contract with the thermal expansion and contraction of the cell, thereby improving the reliability of the cell throughout its life cycle. In terms of structural strength, the integrated energy unit is composed of battery cells and multi-functional elastic interlayers, which can build a more stable force-bearing structure perpendicular to the driving direction, and can also improve the structural strength and impact resistance of the battery pack.
In addition, in the structural design of the bottom of the cell, based on a large amount of real vehicle data and AI simulation, functional modules such as structural protection, high-voltage connection, and thermal runaway exhaust are integrated into the bottom space. This frees up another 6% of usable space for battery placement.
In terms of cooling, Qilin Battery has carried out a new layout design for the cooling system. The water cooling system is directly placed between the large surfaces of the cells, which expands the heat exchange area by 4 times and significantly improves the heat exchange efficiency of the cells. The temperature control time is shortened to half of the original, and functions such as hot start in 5 minutes and fast charging from 10% to 80% in 10 minutes are realized, and the fast charging needs of higher current and higher voltage are met. In extreme cases, rapid cooling can also effectively block the heat conduction between the cells and avoid the spread of thermal runaway.
