Following a sneak preview in March, CATL presented the production version of its third-generation cell-to-pack battery (CTP), now called Qilin instead of Kirin. The pack should be capable of delivering a mileage of more than 1 000 kilometers and features a “disruptive” cooling technique.
No modules. No additional wiring. More battery for the same space. That’s cell-to-pack technology in a nutshell. These packs are much better at optimizing their volume and reaching higher energy densities, making them the best evolution in the field so far, resulting in supplementary range as one of their most important benefits.
Chinese supplier CATL was the first to launch a CTP pack in 2019 and has now unveiled generation three. It’s a significant step forward, as the chief engineer Wu Kai projected at the Chinese EV100 forum earlier this year.
Volume utilization efficiency has risen to 72% (compared to 55% in the first generation), and the energy density can reach 255 Wh/kg with nickel-cadmium-manganese cells (NCM). Combined with safer and longer lifecycle lithium-ferro-phosphate cells (LFP), the density reaches 160 Wh/kg, an improvement of 10 Wh on the best-performing LFP pack made by Chinese manufacturer BYD.
‘In a breeze’
No battery pack in the world crams so many prismatic cells on this particular space than Qilin. The company claims ranges of 1 000 kilometers “in a breeze”. The volumetric efficiency is due to the pack switching to a sandwich structure with an elastic interlayer (instead of a previous three-in-one design), making higher cells possible.
With these specifications, CATL confirms that their CTP technology outperforms Tesla’s latest evolution in battery technology, the 4860 cells. However, the advantage comes down to 13% with comparable chemistry and size.
However, it is unlikely that this 3.0 version won’t feature in the Tesla Model 3 and Model Y cars made in its Shanghai factory. CATL, stating that the packs will go into production in 2023, doesn’t specify the identity of its first customer, but it already supplies Tesla with LFP cells in China. Moreover, adopting the new generation pack would raise the energy density for the American EVs by 28%.
Fast-charging in 10 minutes
Separating the cells are multifunctional slots that can cool or heat. CAT calls them “disruptive”, primarily because it’s no longer a plate design and because of the speed at which they can enhance warming up in cold conditions and vice versa. They support hot starts in five minutes and enable fast charging in ten minutes. In extreme circumstances, the structure can cool down the cells rapidly, offering safer control in case of defective cells. There’s also a protective vent for thermal runaways.
The development of Qilin is also a win for prismatic cells as the better battery format than cylindrical cells, as used by Tesla.