"We're doing this to go further." This slightly chicken soup-flavored phrase is indeed very appropriate for electric vehicles.
Since the birth of electric vehicles, how to make the mileage higher has become the goal of the entire industry. I don't know when it started, "1000 kilometers" has become an "obsession" of electric vehicles. Although most fuel vehicles may not be able to run 1,000 kilometers with a tank of fuel, "endurance breaks a thousand" sets an anchor point for the hearts of electric vehicle users to feel secure: "After 1,000 kilometers, I will not be anxious about mileage."
It is precisely because of this "obsession" that 1,000 kilometers has become a gimmick frequently appeared at the press conference. However, whether it is Weilai's release of a 150kWh semi-solid-state battery with a range of 1000 kilometers, an AION LX PLUS with a range of 1008 kilometers, or a 1000-kilometer endurance of the Zhiji L7, it is a surprise for us, but it is also more of an expectation. After all, it will take a while to wait for the delivery of the product, and we will not be able to see the measured battery life before that.
That's why the shock was different last week when the Mercedes-Benz VISION EQXX concept achieved a single charge in Europe for more than 1,000 kilometers.
Some people may ask, "Do you really need a range of 1,000 kilometers?"
Before discussing whether it is necessary or not, let's first consider the question of "can not". After all, only when it is realized can we have the freedom to choose.
For battery life, do you know how hard "it" works?
A few years ago, there was a very popular joke in the rice circle, "Do you know how hard my brother works?"
It may be difficult for us to detect how much effort aid beans have put in; but for the battery life of electric vehicles, it is really a gain for every effort. Every bit of technological improvement is truly reflected in the energy consumption and mileage of electric vehicles, and numbers are the most intuitive measurement tools.
A few days ago, the Mercedes-Benz VISION EQXX concept car departed from Sindelfingen, Germany, with a high-speed cruising speed of 140 km / h and an average speed of 87.4 km / h, through multiple road conditions such as highways and mountain tunnels, through the complex climate of wind and rain, slippery, high and low temperature differences, and finally arrived in Cassis, France.
After a single charge, the journey lasted 11.5 hours, covered more than 1,000 kilometers, and had about 15 percent of the remaining charge at the finish line, which is about 140 km of cruising range. For the most "eating" high-speed road conditions, the whole process of such a high-speed driving undoubtedly puts forward a lot of tests for endurance.
What efforts has EQXX made for this energy efficiency journey?
01
Long battery life ≠ stack of battery packs
When it comes to mileage, the first thing that comes to mind is the power battery. After all, electric vehicles are not perpetual motion machines, and even the energy-saving design of cattle cannot get rid of the power battery power to walk independently.
At this stage, in the case of lithium battery energy density is difficult to achieve a qualitative leap, the most direct means of long endurance is "stack battery": expand the battery pack, double the battery capacity, and always achieve the effect of "vigorous miracle".
However, in reality, the simple stacking of battery packs, while increasing the battery capacity, the weight of the whole vehicle has also increased, so that the car can carry the weight forward, and the increased battery capacity is consumed by the battery pack itself, while sacrificing the space of the chassis and the handling of the whole vehicle, which is not worth the loss.
The VISION EQXX Concept is equipped with a power battery of nearly 100kWh, which is almost the same as the battery level of the new EQS in terms of capacity, but the battery pack size is reduced by 50% and the weight is reduced by 30% - only 495 kg.
According to the extranet media, the EQXX battery is likely to be jointly built by Mercedes-Benz and Ningde Times, using CTP 3.0 technology, reducing the weight between the battery pack modules, while increasing the energy density to more than 400kW/L through high silicon content anode and other technologies, so it can achieve volume and weight compression. The active cell balancing function also ensures that energy is drawn evenly from each battery to improve efficiency during endurance.
Increasing the energy density by increasing the silicon content of the electrode is not just the way the Mercedes-Benz family plays. Previously, the 150kWh semi-solid-state battery released by Weilai achieved an energy density of 360Wh/kg through the method of inorganic pre-lithionized silicon carbon anode; Tesla 4680 also achieved a breakthrough in the energy density of lithium batteries through the high nickel and silicon-based anode route. "Silicon-doped lithium" is the main means for lithium batteries to improve energy density at this stage.
With the gradual landing of this series of lithium batteries with high silicon content, it is believed that in the next period of time, the mileage of electric vehicles will have a big breakthrough.
EQXX has made great efforts in the power battery while improving the energy density of the power battery. For example, the vision EQXX concept car's electric drive consists of an electric motor, transmission and power electronics, developed by Mercedes-Benz in collaboration with F1 experts from High Performance Powertrain GmbH (HPP), with a peak output of 180 kilowatts and the ability to transfer up to 95% of the battery energy directly to the wheels. In order to maximize the range, Mercedes-Benz engineers succeeded in reducing the losses of the VISION EQXX concept drivetrain (electric motor, inverter and transmission) by 44%, combined with 900V high-voltage pure electric technology.
02
Black technologies that reduce "power consumption"
If it is said that increasing battery capacity gives electric vehicles more capital to "squander" electric energy, then reducing energy consumption requires the accumulation of vehicle design bits and pieces.
In this test, the overall energy consumption of EQXX reached 8.7 kWh per 100 kilometers. It should be known that the energy consumption of 100 kilometers of Tesla Model 3, Xiaopeng P7 and other common electric cars is about 13.5kWh, and the energy consumption of 100 kilometers of BMW iX3 is close to 14kWh, and limited by the size of the vehicle, Mercedes-Benz's own EQS 100 kilometers energy consumption is 20kWh. The energy consumption of the EQXX concept car at the time of release was 100 km 10 kWh, which was lower in actual measurements, and in order to achieve this goal, it can be said that it is "armed to the teeth".
When it comes to reducing energy consumption, one of the models that must be mentioned is the Volkswagen XL 1.
As an ultra-energy-efficient predecessor, the Volkswagen XL 1 has the lowest wind resistance in a production car - 0.189, and the fuel consumption per 100 kilometers is only 0.92L. To achieve ultra-energy savings, the Volkswagen XL 1 utilizes a large amount of carbon fiber material to reduce vehicle weight, reduce wind resistance through a streamlined design, and reduce the center of gravity. At the same time, through the ultra-narrow tire design, most of the body weight is borne by the rear wheels to ensure driving maneuverability.
Fuel-intensive cars each have their own fuel costs, but energy-saving vehicles, energy-saving means can often find similarities.
Similar to volkswagen XL 1, the energy-saving king of fuel vehicles, in order to achieve the purpose of extreme energy saving, EQXX also does its homework in various aspects such as wind resistance, weight reduction, and tires.
When EQXX's predecessor, EQS, was unveiled, the low wind resistance of 0.2Cd surprised everyone. It should be known that the wind resistance is directly proportional to the square of the speed, and for pure electric vehicles, the wind resistance under high-speed driving has a greater impact on the car. Data show that for every 0.01Cd reduction in the wind resistance of pure electric vehicles, the cruising range can be increased by 5 to 8km. On the basis of EQS, EQXX reduces the drag coefficient to 0.17Cd, which is reduced by 0.03C. To achieve this, body lines, the front face, the wheelbase, and even the tires all contribute.
The roof curve is smooth and smooth, gracefully extending like a water droplet to the rear of the car, and the extremely low windward area of 2.12 square meters and the compact rear track enhance aerodynamic performance. At speeds of 60 km/h, the active rear diffuser automatically opens to optimize airflow, significantly reducing the drag coefficient. Mercedes-Benz has partnered with Bridgestone to reduce the roll resistance coefficient of vision EQXX concept tires to 4.7, further optimizing energy efficiency.
The vision EQXX concept's electric drivetrain produces virtually no waste heat, and the heat sink mounted on the vehicle's baseplate uses airflow to evenly cool the drivetrain, increasing the vehicle's range by approximately 20 km.
While reducing the wind resistance, the weight reduction of the body is also carried out simultaneously. The VISION EQXX concept car has an empty weight of only 1755kg, in addition to the high-energy density power battery with a weight of only 495kg mentioned earlier, the body draws on the weight reduction process of formula 1 racing cars and uses sustainable carbon fiber-sugarcane composite materials; the BIONEQXXTM rear bottom plate casting uses an aluminum integrated casting process, reducing the weight of splicing between multiple parts, reducing weight by 20%.
By reducing wind resistance and vehicle weight, EQXX reduces energy consumption to the extreme with a lighter attitude.
03
Those "life-sustaining" tricks
On the one hand, it is to improve battery capacity and energy utilization, and on the other hand, to reduce vehicle energy consumption, EQXX can be said to be used to the extreme in "open source and throttling". But I have to say that vision EQXX also has a lot of help in this 1000-kilometer long-distance attack.
For example, the VISION EQXX concept car is equipped with 117 solar panels on the roof, which begin to charge the 12V battery system in the Po River Valley near Milan, providing power needs such as navigation. Although the conversion rate of solar power is limited and the generated electrical energy cannot directly drive the vehicle, with this additional energy, the electric power in the power battery that was originally used for entertainment equipment such as navigation is saved, indirectly extending the additional endurance of 25km.
At the same time, during this 1000-kilometer drive, the VISION EQXX concept car went through a long downhill road, which was further replenished by energy recovery through the electric braking system. Using energy recovery to replenish energy sounds like a bit of a "no win", after all, if you choose a downhill test, the energy recovery system will not be able to extend the range indefinitely. But for an 11.5-hour journey, where to find that big downhill? The electrical energy recovered by the braking system is more of a fraction of the endurance increased.
Where is the threshold for breaking endurance anxiety?
Whether it is the 1000 km actual measurement of vision EQXX, or the previous GAC AION, Weilai, and Zhiji claiming to break through 1000 km endurance, we will hear different voices: Do we really need 1000 km endurance? When the electric car reaches 1000 kilometers, will there still be range anxiety?
It is true that most fuel vehicles can not run 1000km with a tank of fuel, and few people will have the need to run long distances in daily life, but battery life and replenishment are like "hoarding goods" in the refrigerator, which may not be used in ordinary times, but when they think of special periods, they have become synonymous with "security". The endurance, energy replenishment system, fast charging, and power exchange are not mutually exclusive. For example, the VISION EQXX concept car uses a 900V high-voltage system while having a long endurance, which reserves fast charging capacity for future mass production models.
For car companies, improving the mileage, whether it is to improve the energy density of the power battery, reduce energy consumption through design, or supplement the energy through solar panels, is a gradual attempt at technological innovation, trying to achieve a goal to the extreme. When the market needs it, these innovative technologies will become their moat.
At last
Vision EQXX's 1,000 km measurement reminds me of the famous marathon "Break 2 Challenge".
At the 2019 Vienna Marathon, the organizers chose the most suitable weather, location, and professional pacemakers to break the wind, and finally Kipchoge achieved the first two-hour marathon for humans. Some people may question the elaborate arrangement of the challenge, but no one will question Kipchoge's ability, and no one will question the significance of "breaking 2" to the human limit. Because challenging the limit itself requires the all-round cooperation of time and place and ultimate technology.
The same is true of today's electric vehicles. "1,000 kilometers" seems to be a "benchmark" that is close at hand for mass-produced electric vehicles. Maybe it's hard for us to use 1,000 kilometers in our lives, but we can't deny its significance for electric vehicles; maybe these technologies have been repeatedly verified in the laboratory, but from the laboratory to the concept car, from the concept car to the actual test road, there are countless bumps.
Because of this, when the VISION EQXX concept car completes a journey of 1000 kilometers on a single charge, it is not only an energy efficiency journey, but also allows us to see the extreme that traditional car companies can do for a goal. As a concept car, VISON EQXX carries not only the concept, but the obsession with technological innovation, and the original intention of the automotive industry to verify the theory.
Maybe one day in the future, when the EQXX mass production car version finally landed, some of today's exquisite designs may not all appear on the mass production car, and the driving habits, environmental climate and other factors in reality will also affect the actual endurance of the mass production car, but this does not negate their value, they are the exploration of electric vehicles on the road of continuous growth.
Maybe in a few years, there will be one production car after another with a range of 1,000 kilometers, but we will remember the "zero breakthrough" in the first actual test, just as we remember the birth of the first diesel locomotive.