Battery cells to be integrated within the vehicle frame.

The Chinese lithium-ion battery manufacturer Contemporary Amperex Technology Co. Limited (CATL) announced that is working on a new approach to further increase the energy density of battery systems and as a result, the range of electric vehicles will go beyond 800 km (500 miles).

The initial approach was to produce battery cells, combine multiple cells into modules, and multiple modules into packs. Some bigger EVs may have multiple packs as well, but in electric cars there is usually a single battery pack.

The newer Cell-To-Pack (CTP) approach (already used by CATL and BYD for LFP chemistry) was to make a specific type of cells, to skip the module stage, and make packs directly from the cells. It saves space, and also weight. BYD Blade Batteries have about 50% higher volumetric energy density compared to a conventional LFP.

The next step may be the integration of the battery with the vehicle on a deeper level in a Cell-To-Chassis (CTC) approach, which skips not only modules but also the independent pack unit. As we understand, the cells to be directly integrated within the vehicle chassis/frame.

The obvious advantage should be higher energy density and maybe also cost, although there may be some drawbacks, as it will be difficult to service the battery (no option to replace faulty modules).

To use CTC, the vehicle manufacturer will have to design a modified version of the chassis/frame, in which the cells would be inserted and integrated with BMS and thermal management system.

We look forward to hearing whether there are automakers interested in the CTC.