The snow has cooled down in many places, and the electric rear-wheel drive car cannot be driven?
It seems that new energy vehicles are afraid of cold and become a technical topic that is discussed every year. No, under this round of cold wave that swept the country, the owners of new energy vehicles have begun to complain. For example, an online ride-hailing driver from Shanghai recently took nearly twice as long as usual to reach a range of more than 400 kilometers. This is only one aspect of charging, and in terms of battery life, performance, and control safety, new energy vehicles have technical limitations in all aspects of cold sensitivity. So have these complaints, which I hear every year, improved from a technical point of view?
As long as the range is piled up enough, the electric car is not afraid of the cold?
New energy vehicles are afraid of cold is a problem that comes with genes, even if it is a fuel vehicle, it is easy to encounter the phenomenon of difficulty in starting at low temperatures. The main reason is that the core battery cell materials used at this stage will essentially reduce the activity of the battery due to low temperature, which will affect the battery life and performance release. Even if ternary lithium is more frost-resistant than lithium iron phosphate, this is only relative. What's more, the loading volume of lithium iron phosphate batteries is far ahead.
However, the shortcomings of talent can be made up for by the day after tomorrow. Sort out the core of the power battery's cold fear, although there are anxieties about battery life, heating, performance and other aspects. But they all end up at one point, and that's battery capacity. Among them, it can be refined into the capacity of the battery itself, as well as the convenience of energy replenishment. That is to say, in the case of the user's "power in hand", the so-called new energy vehicles are afraid of cold and can be washed away by a miracle.
In order to achieve a long battery life, under the existing technical conditions, it is mainly through two sets of solutions: improving the capacity of the battery cell or increasing the usable volume of the battery pack. In terms of battery cells, even lithium iron phosphate batteries, including CATL and BYD, have developed lithium manganese iron phosphate or similar technical solutions. The intention is to improve the capacity of the battery cell while maintaining the stability of lithium iron phosphate. Another technical case is the gold brick battery of ZEEKR automobile, which has just landed. The same lithium iron phosphate technology route also improves the performance by improving the activity of the positive electrode and strengthening the efficiency of lithium-ion de-intercalation by quickly opening up the electrolyte, negative electrode and other pathways. For example, on the basis of lithium iron phosphate batteries, it is compatible with 800V high-voltage platforms. Of course, if you want to fundamentally solve the anxiety caused by the cold, from a technical point of view, you have to wait until the final landing of technologies such as sodium batteries and solid-state batteries.
As for the technical route of battery packs, it has been widely used. For example, BYD's CTB and Tesla's CTC technology, etc., are all integrated into the interior structure of the power battery, so that it can gain more space for the layout of battery cells. Similarly, CATL's Kirin battery achieves a more efficient cell layout through a non-modular layout. With the ternary lithium battery, the overall energy density can be increased to the level of 255Wh/kg, which can easily achieve thousands of miles of battery life. A real-life example is the ZEEKR 001 with CATL's 140kWh battery pack, which has a CLTC pure electric range of 1,032 kilometers.
With longer cruising range and efficient charging technologies such as 800V high-voltage platforms, charging infrastructure will eventually have to be able to keep up. Because in terms of DC fast charging, domestic car companies generally use high-voltage solutions, rather than Tesla's high-current solutions. Therefore, it naturally matches the 800V high-voltage path of pure electric vehicles. Typical representatives include Xpeng Motors and Huawei. Among them, Xpeng has launched its own S4 super fast charging pile last year, with a maximum charging power of 480kW. Huawei also announced not long ago that it will lay more than 100,000 liquid-cooled ultra-fast charging piles next year. From a technical point of view, Huawei and Xpeng's super fast charging piles have applied liquid cooling technology. It has greater advantages in terms of durability, lightness, and practicality. The application of SiC materials has technically rolled the charging pile to a level with pure electric vehicles. Whether it is efficiency or power, it has pushed the energy supplement of electric vehicles to the era of calculation by seconds (according to rough calculations, if the model is matched, Huawei's charging pile can achieve 1 km of charging in 1 second).
Plug-in mixing and range extension, unexpectedly achieving dimensionality reduction strikes?
After talking about how pure electric vehicles can fight the cold at this stage, you will suddenly find that on this problem, plug-in hybrid (including extended range) models are simply a dimensionality reduction blow? First of all, range anxiety is about the same as non-existent for them. And thanks to the technological advancement of battery cells, the capacity of batteries that can be carried per unit area is also increasing. Among the new cars launched this year, it is already difficult to see plug-in hybrid products with a pure electric range of only more than 50 kilometers. What's more interesting is that the plug-in hybrid (including range extender) model retains the internal combustion engine structure. Therefore, it is theoretically possible to use the waste heat generated by the internal combustion engine to provide heat energy for the cockpit and the battery itself after the water temperature rises. This greatly alleviates energy consumption and improves its own efficiency, which can be regarded as the advantages of both traditional fuel vehicles and pure electric vehicles in another dimension.
And on the issue of fighting the cold, plug-in mixing (including range extension) even has a "windfall". Similarly, due to the retention of the internal combustion engine structure, plug-in hybrid (including range extender) models still need to retain the drive structure on the front axle in most cases, even after deep electrification (unless the original longitudinal rear-wheel drive models such as Mercedes-Benz and BMW can still maintain the rear-wheel drive characteristics after adding a P2 motor). As a result, plug-in hybrid (including extended range) models are naturally technically suitable for front-wheel drive or four-wheel drive architecture. Especially after stripping the mechanical structure such as the transmission shaft, the four-wheel drive structure is objectively lowered by the new energy. Haval Hi4 technology is one of the representatives, P2 + P4 dual motor structure, can easily achieve four-wheel drive. That is, it bypasses the limitations of the traditional longitudinal engine single P2 motor, and compared with the P1+P3+P4 structure, it can achieve controllable cost. However, the above scheme also has a premise, that is, plug-in hybrid (including extended range) in the state of feed-in, the user can resist the cost of using fuel. After all, their all-electric range has increased, and they can't compare with the pure electric models of the same period. Therefore, when the vehicle is in a cold state, the risk of encountering power feeding scenarios will increase.
So why are pure electric vehicles, especially excluding cheap scooters that are mainly front-wheel-drive, mid-to-high-end pure electric vehicles are keen to build rear-wheel drive? Once upon a time, 10,000-rotor motors were called high speeds. But at present, such as Tesla, Huawei, etc., have pushed the speed of a single motor to more than 20,000 rpm. Not to mention the performance, the single-motor rear drive is already in a "surplus" state. Ultra-high-speed motors are even blocking the technical solution of electric vehicle gearboxes. On this basis, the front motor is also added, which is not only unnecessary, but also affects the space that has been saved with great difficulty. Because of the redundancy of space on the front axle, it can be used to arrange more complex suspension structures and even reserve more space for the front and rear counterweights of the vehicle. As you can see, all the technical routes in this area revolve around performance and driving experience. In the same situation, even a fuel vehicle will inevitably test the driver's skills on ice and snow roads.
It's just that for pure electric vehicles, due to the characteristics of the motor output, as well as the absolute advantage in power and torque. Even in most cases with a better center of gravity and even better tires, rear-wheel drive BEVs are still more likely to push the limits of grip. Technically, this could be done by strengthening the limited-slip function, such as a more targeted adjustment of the stability system, or simply equipping it with a rear axle differential. Of course, the latter will undoubtedly push up the cost, so at this stage it is mainly equipped on more expensive models. For more drivers, it is more feasible to choose to develop their driving skills or simply change their snow tires.
In general, new energy vehicles are afraid of cold, and the core is still in battery technology. Before the revolutionary upgrade of battery cell materials, this symptom of cold sensitivity can only be overcome, and it cannot be theoretically eradicated for the time being. However, the larger-capacity battery, more stable performance, and faster energy replenishment have greatly alleviated the anxiety of new energy vehicles at this stage. Even if we take the pure electric rear-drive model that is "most afraid of cold" as an example, as long as it can achieve stable energy replenishment, then under the current technical conditions, it is still a joke to be afraid of cold.