Blade battery vs CTP structure comparison
As the exporters of China’s new energy technology, CATL and BYD in top 10 lithium iron phosphate power battery manufacturers have both released their own battery integration technology on top of this trend. CATL’s CTP (CellToPack) technology route is based on a high-nickel ternary lithium structure.
Its core is to reduce the number of modules, directly form standardized battery packs from multiple large-capacity cells, and then flexibly stack to form larger battery modules to meet the energy storage needs of different vehicle models.
Comparing blade battery vs CTP, BYD’s blade battery is based on the lithium iron phosphate technology it is good at, and the battery cell also evolves to large capacity. However, the shape of the battery cell is flatter and narrower, so it is named blade battery figuratively. Multiple blades are bundled to form a battery pack module, and a battery module is formed by combining a few large modules.
Structural durability comparison of blade battery vs CTP
As a large-mass single component arranged on the bottom of the vehicle, the battery module must consider the adaptability of the structural strength to the complex vehicle environment. The ability to resist side impact is the most obvious demand, and manufacturers often improve this ability through the structure and material use of battery pack casings.
However, for long-term use of private cars, non-load-bearing bodies are generally used without girder, and the battery structure also needs to be able to withstand long-term stress changes caused by repeated body deformation.
Through structural analysis, CATL’s CTP technology is more susceptible to the repeated diagonal shear stress because of the consideration of the maximization of volume packaging efficiency. The connection of high-voltage wiring harnesses and cooling systems is challenging, and the reliability of long-term use remains to be verified. Compared with blade battery vs CTP, BYD blade battery actually still retains the overall configuration of module packaging and battery pack packaging.
At the same time, it can be seen from the patent drawing that the battery pack package will be able to reserve deformation space according to the needs of the model to avoid direct stress on the ultra-thin and large cells. Structural durability comparison of blade battery vs CTP, BYD blade battery package is easier to make reliable products.
However, such an insurance structure also brings other problems. Judging from the data released so far, BYD uses volume power density as a measure, but has not released the weight power density data that has been widely used.
It can be guessed that the specific energy of its structural weight superimposed on the iron battery itself is not high, resulting in no significant breakthrough in its weight power density on the standard measurement platform of the Ministry of Industry and Information Technology.
According to previous information, it is expected that the power density of blade batteries in a package may reach about 180Wh/kg, which is at the current mainstream level.
Structural compatibility comparison of blade battery vs CTP
As a single battery and related technology supplier, CATL needs to face more product matching considerations. However, judging from the details of the current patent, the height of the CTP large module cannot be changed, and at the same time, it needs to be matched with a matching shell to be adapted to be installed on different models. Such a structure requires OEMs to make corresponding adjustments in product planning.
The more difficult problem is that there is currently no large-scale sales as the support for development, and the risk of manufacturers needing to make design adjustments for the configuration of a single battery supplier is very large.
As also one of top 10 lithium ion battery manufacturers BYD, which produces new energy vehicles by itself, blade battery vs CTP, blade battery may have taken into account the multi-specification adaptability needs of its own products from the very beginning.
The narrow edge of the blade is made as small as possible, which means that the vertical height can be more easily adapted to the needs of high-riding and low-riding models. In the future, multi-purpose vehicles with ultra-thin chassis can be developed based on this, so that users can use more space and tap the advantages of new energy vehicles.
At the same time, we also see that the stacking application of this ultra-thin battery is possible, which may be prepared for commercial and high-chassis large SUV products, which can store more energy.
Comparison of configuration characteristics of blade battery vs CTP monomer
Another feature of the CATL CTP battery is the large capacity of the single cell. The single cell capacity has increased from the initial 50Ah to more than 200Ah, which greatly reduces the proportion of the casing.
At the same time, when the charging and discharging rate remains unchanged, a simple series structure can output or accept a larger current (improving power and charging convenience).
In addition, the current public information of CATL shows that the CTP battery pack will still be packaged in a square shell. Considering the stability of the current high-nickel battery, this package should be a better choice.
Compared with blade battery vs CTP, the single design of BYD blade battery is a little surprising. First, such a large monomer length is not a stable mechanical structure, and the deformation resistance is very weak when subjected to lateral force. Usually, the internal pressure of the battery causes the casing to expand, which in turn puts pressure on the surrounding batteries.
Therefore, it is necessary to carefully consider the gap problem when forming a group. On the one hand, it is necessary to prevent shocks, and on the other hand, it is necessary to eliminate the side force. There is still a lack of evidence in this regard.
Another technical challenge may come from the internal winding method of the cell, and it is speculated that the interior of the battery will be in the form of multiple electrodes + multiple independent winding units. In fact, it can be seen as a large battery composed of multiple small batteries, but these small batteries share a package.
Conclusion
Overall, blade battery vs CTP has its own merits. CATL’s CTP has higher power density and higher group efficiency. It is more friendly to most OEMs for cost control, and it is easier to launch products with longer battery life under the premise of a certain weight. BYD’s blade battery is more valuable and imaginative in terms of structural flexibility and durability, greatly increasing the performance of iron batteries, allowing it to return to the mainstream from commercial or low-end products. This has to be said to be a considerable improvement.
From another point of view, the difference in the technical architecture of the two also shows a fact. Although the two companies are both technology exporters of new energy vehicles, BYD itself has advantages as an OEM’s technology accumulation. This advantage may not depend on the improvement of a single indicator, but more on the understanding and rationalization of the user environment.