Recently, electric vehicle technology has been a constant surprise.
Ningwang has just announced that it will mass-produce electric vehicles with a range of 1,000 kilometers in 2023.
Immediately after, Mercedes announced that their new battery pack could already enable electric vehicles to travel more than 1,000 kilometers in the real world, equivalent to consuming less than 10 kilowatt hours (kWh) of energy per 100 kilometers.
Note that this is the actual mileage, not the theoretical range.
Driving range is a function of the weight, aerodynamics, driving mode and total energy stored in the battery of the electric vehicle, simplifying the equation to obtain a linear relationship between the mileage and the energy density of the battery pack, that is, the higher the energy density of the battery pack, the higher the mileage.
Therefore, increasing the energy density of the battery pack can increase the range of electric vehicles. In addition to the improvement of the energy density of the battery pack, the reduction of vehicle weight is also an important factor in improving the cruising range
The latest CTP technology is the key to Ning Wang and Mercedes announcing that the range of electric vehicles reaches and exceeds 1,000 kilometers.
Let's take a look at what CTP technology is. CTP is the abbreviation of cell-to-pack, meaning single battery to battery pack, is an integrated battery pack technology, that is, by optimizing the effective volume of the battery to increase the energy density of the battery pack.
CTP has recently appeared frequently in the electric vehicle industry because car companies are increasingly favoring this technology. It has the potential to increase capacity utilization by approximately 15 to 50 percent, depending on the battery cell formula.
In addition, the number of parts can be reduced by up to 40%. Following this design philosophy, car manufacturers can also choose to take advantage of the energy density of battery packs to use cheaper, lower energy density batteries, such as lithium iron phosphate batteries.
Therefore, while the energy density of lithium iron phosphate batteries does lag behind that of ternary lithium batteries at the single-cell level, the application of CTP technology has significantly narrowed the gap in packaging grades, and the energy density of state-of-the-art LFP batteries has reached 180 Wh/kg.
Inspired by a shared vision of cost-effective, high-performance, and secure batteries, most EV manufacturers prefer a universal battery pack configuration consisting of numerous battery modules. Each of these modules consists of a separate set of battery cells. These modules and batteries are usually liquid-cooled and intelligently monitored and managed by the battery management system.
However, this modular design is not ideal. For example, inactive areas of a module—housings, terminal blocks, side panels, internal connectors, battery management, and cooling systems—can all add weight, take up valuable bulk, and ultimately affect the energy density of the battery pack.
Given these drawbacks, many EV and battery manufacturers are eliminating modules altogether, opting instead to use CTP technology to integrate large-size batteries directly into the battery pack.
A typical example is BYD's blade battery, where a single cell spans the entire width of the battery pack, providing battery-to-battery connectivity. The integration efficiency of the battery pack has increased by more than 50%. Although the nominal voltage is maintained at 3.2 volts and the energy density is 166 Wh/kg, the CTP architecture increases the volumetric energy density to 448 Wh/L.
However, large-capacity batteries are commonly used in CTP battery packs, and the charge/discharge characteristics of a particular battery are bound to vary greatly, or even degrade at different rates. This imbalance not only affects performance, but even poses a security risk.
To ensure that all batteries in the battery pack perform at their best, battery scientists have developed a "self-healing" system that utilizes a set of software algorithms and corresponding hardware to identify and proactively repair a battery or string of batteries to restore it to an optimized level of performance. This ensures uniform battery performance throughout the battery pack.
With growing interest in CTP technology, manufacturers are looking for innovative ways to further optimize these battery packs. So while active liquid cooling has become the standard in eviction design, cooling systems require pumps, piping, and coolant, which consumes energy and adds weight.
Mercedes' CTP technology is relatively new, and their innovation lies in the use of passive cooling (air cooling) methods to dissipate heat from the battery pack.
This passive cooling is achieved through intelligent battery management throughout the battery pack, combined with an integrated cooling plate at the bottom, as well as vents that open as the temperature rises.
These are able to shrink the shape of the battery and pack huge energy contents into a very small space, so their battery pack weight is reduced by 30%, and the energy density of the battery pack is close to 400 Wh/L.
With increased battery pack energy density and reduced vehicle weight, this innovative CTP technology enables electric vehicles to actually last more than 1,000 kilometers.
This article is the original of science and technology cool probe, plagiarism must be investigated!
The author is a doctor of the Chinese Academy of Sciences, a researcher of the American Fujian University, science and technology control, contact with front-line scientific and technological research and development, willing to share, welcome to pay attention to science and technology cool detective.