1000km measured endurance, which concepts on the EQXX can be illuminated into reality?

It is said that the concept of Lin Chiling, mass production of Luo Yufeng, then EQXX's wonderful 1000 +km endurance and 8.7kWh/100km ultra-low energy consumption behind what technology can be applied in the mass production car?

Although the EQXX is already a road model that can be put on the road, just as car companies can mass-produce and sell 200 prototypes for Group B racing cars, the purpose of EQXX development is not to mass-produce itself, but to verify technology. So a lot of design and technology is radical, not universal.

This means that some technologies can be seen in the wider EQ series, while others cannot. This article will take a look at the core technologies that achieve EQXX ultra-long endurance and ultra-low energy consumption, such as the ultra-low wind resistance coefficient of 0.17, the high-efficiency electric drive system, the lightweight body, the high-energy density battery pack, etc., which is close to us and which is far.

The lowest drag coefficient in the legal road model - 0.17

Like the EQS, which has the lowest wind resistance in production cars, the EQXX has an unforgettable and unique shape, with a drag coefficient of only 0.17, and this concept of low wind resistance does not sacrifice its beauty and legitimacy: the EQXX still uses traditional rearview mirrors. But that doesn't mean the 0.17 of the EQXX can simply be replicated in a production model.

As mentioned in the previous lecture hall, the vehicle wind resistance has four main components, the largest and most core of which is called the appearance resistance or pressure difference resistance, which is the resistance between the high pressure in front of the vehicle and the low pressure of the vortex left at the rear of the vehicle after the vehicle breaks the wind.

The vortex behind the rear of the car is the main source of low air pressure, and in simple terms, the vortex is like a small whirlpool dragging the car behind the butt, the more and larger the whirlpool, the greater the resistance. The best way to address this drag is to lengthen the rear and make it flatter and narrower like a real tail. This allows the airflow to flow as closely as possible along the body to maintain a laminar flow state, reducing the vortex behind the rear of the car.

From the side view, it can be clearly seen that the tail of the EQXX is not only long, but also the slip curve does not stop at the height of the window, but continues to dive downwards, and the bottom of the car also has a tendency to rise.

As you can see from the top view, from the rear wheel arch to the rear, the rear of the car is also narrowing, and the rear wheelbase of the EQXX is 2 inches smaller than the front wheelbase. Such a design is extremely detrimental to the practicality of the trunk. And the excessively long rear suspension also brings problems with body proportions. The EQS's compromise on the design of wind resistance has been controversial.

For EQXX, I can only admire that Mercedes-Benz's styling design skills are indeed excellent, so that this forced service drag coefficient of the shape still carries some elegant beauty.

In order to ensure practicality, this extreme long tail will inevitably be impossible to retain in the commercial production car, but there are some technologies on the EQXX management wind resistance that can be borrowed by the mass production model, such as the active airflow management components in front of and behind the body, especially the active diffuser at the rear, the ultra-smooth A-pillar and so on.

The drag coefficient of 0.17 is still out of reach, but it can save a little.

4.7 Low rolling resistance ultra-narrow tires with rolling resistance coefficient

Bridgestone customized the Terranza Eco tire for the Mercedes-Benz EQXX, which uses ENLITEN technology to reduce the weight of the tire by 10% and the rolling resistance by 20%.

EQXX's tires have been deeply customized, with sidewall and bead areas optimized to match the hood mounted on 20-inch forged magnesium wheels, greatly improving the aerodynamics of the tires. Compared with the current low-wind resistance wheels, which mainly modify the hub spokes, the Design Concept of Mercedes-Benz goes a step further, and the tire wall has become an object of optimization.

In order to achieve ultra-low rolling resistance, the tire width of this tire is only 185, and the formula and pattern of the low rolling resistance tire can be promoted and applied, but the width of 185 is really not related to the production car. Versailles' 205 is a lesson for the past.

Is the high energy density battery brought by air cooling a clever or effective?

EQXX provides a 100kWh battery pack at the same time, the empty load weight is only 1755 kg, and a 60 kWh model 3 is comparable, and the lightweight work is quite excellent. Compared to the 107.8-degree battery pack on the EQS, the volume is reduced by 50% and the weight is reduced by 30%.

The largest contribution is naturally the volume energy density of the battery pack, and the mass energy density is improved. The 100kWh battery pack weighs only 495kg overall, with a mass specific energy density of 202Wh/kg and a volume specific energy density of 400Wh/L. All are at the top level in the world.

The main technical features of this battery pack include: 1. Anode doped silicon to increase the specific capacity, thereby improving the energy density of the battery cell; 2.CTP moduleless design; 3. Passive cooling system; 4.900V high voltage.

With the exception of the 900V high voltage, none of the other three technologies are far ahead. The first two do not need to be said much, respectively, the current two representatives of the development of battery cell materials and engineering design, there have been many practical application cases. Passive cooling systems, commonly known as battery air cooling, are somewhat ambiguous.

Passive air cooling allows the battery pack to reduce cooling ducts, coolant, water pumps, and heat exchangers, which are beneficial to both weight and volume. According to Mercedes-Benz calculations, compared with liquid cooling, the cruising range of about 20 kilometers can be increased. From the perspective of cooling efficiency, passive air cooling is certainly not as good as active liquid cooling, which is bound to be unable to cope with the cooling requirements of the battery pack at a large power output.

But for the other design and needs of EQXX, passive cooling is not so unforgivable. After all, EQXX is designed for battery life, not performance, and it is equipped with only a 150kW electric motor, and there are fewer applications for high power output. The low current and low loss brought by the 900V high voltage platform also make the heat generation of the whole electric drive system itself low.

The opposite of passive air cooling of the battery

Active air cooling of the whole vehicle

And EQXX is equipped with an active cooling system. When air conditioning refrigeration needs to be turned on through hot environments, or when a heat pump is running in cold weather, the air conditioning system activates the "smart air curtain" of the active intake grille to open an additional air diversion channel. The air channel connects the high-pressure zone at the front of the car with the low-pressure zone at the top of the hood for efficient thermal management with minimal air resistance. Even if the "smart air curtain" is turned on, the wind resistance coefficient increases by only 0.007.

The system effectively directs airflow to cool the battery's integrated heat sink. When the battery temperature rises, the battery pack itself also opens additional vents to gain more airflow for cooling. Passive cooling, active wind control, fun.

It's just that for more models, passive battery cooling is always not a good solution, the heat dissipation limit is not high enough, and it is impossible to actively keep the battery pack warm in winter, which is a fatal injury.

A large number of perforated structural parts are a carnival of materials

In order to achieve the goal of lightweighting, while meeting the perforated structural parts can provide sufficient strength. Mercedes-Benz has also made a drastic investment in the body materials of the vehicle. The MS1500 ultra-high strength martensitic steel used in vision EQXX is the first of its kind for Mercedes-Benz body-in-white applications. The special strength of this material provides excellent occupant protection in the event of a collision while keeping weight to a minimum.

For the first time, vision EQXX's body-in-white also uses electric arc furnace technology to create low-CO2 flat steel produced from 100% scrap. Vision EQXX's doors are made of CFRP and GFRP (carbon fiber and glass fiber reinforced plastic) parts mixed with aluminum reinforced materials. In addition to reducing weight, the design achieves a careful balance of stiffness and ductility in the event of a collision. At the same time, a new polyamide foam strengthens the lower edge of the doors and optimizes energy absorption in side impacts.

More than just body materials, EQXX replaces the traditional steel brake discs with aluminum brake discs, significantly reducing weight. In addition to being completely corrosive-free, the advanced engineering brake system by Mercedes-Benz reduces brake dust emissions by 90 percent with an innovative coating. At the same time, EQXX replaced the traditional coil spring with a new advanced glass fiber reinforced plastic spring developed in collaboration with Rheinmetall Automotive, reducing weight.

It is precisely because of the addition of so many new processes and new materials that EQXX can achieve good enough safety with a body structure that has lost weight and is "full of holes". And these new materials are expected to be applied in more models.

Multi-source heat pump

The heat pump systems used by EQXX can absorb heat from a variety of sources, and it is not uncommon to be able to absorb waste heat from the drive system and the external environment. Miraculously, it is also able to absorb the "enthalpy of evaporators" produced during dehumidification: the potential of water vapor in the air to release in the form of heat when it changes from gaseous to watery.

"One of the best ways to improve efficiency is to reduce losses" – high-performance drive assemblies

EQXX's ultra-efficient electric drivetrain uses a new generation of silicon carbide electronic control, including reducers and drivetrains, and the energy transfer efficiency from the battery to the wheels has reached 95%.

95% of the probability is the peak efficiency, although amazing, but not surprising, the current market first echelon level can also have more than 93%. And if it is the average efficiency of the operating conditions, then this value is quite frightening.

The Formula 1 experts at Mercedes-AMG High Performance Powertrain (HPP) were closely involved in the development of the powertrain. During development, Mercedes-Benz's simulation tools help engineers quickly assess the contribution of system design, material selection, lubrication and thermal management systems to efficiency, so as to quickly identify effective solutions.

The technology of this electric drivetrain is based on the upcoming Mercedes-AMG Project ONE supercar. Although the AMG ONE has been jumping tickets for many years, his various technologies have also begun to contribute to the new generation of Mercedes-Benz models. That's what EQXX makes.

Roof solar cells

The roof of the EQXX is equipped with a total of 117 solar arrays, which were developed in collaboration with the Fraunhofer Institute for Solar Systems ISE, Europe's largest solar energy research institute. Its main role is to power the low-voltage auxiliary equipment on the car, thereby reducing the power consumption of high-voltage batteries. Under ideal conditions, it is possible to save about 25 kilometers of electricity in a single day.

EQXX's solar cells connect the vehicle's lithium iron phosphate battery, look at the display in the upper right corner of the picture, not less than 0.3kW of power generation power can not afford to drag any large pieces, but the supply of the car screen, the vehicle's ECU, ventilation to the air conditioning is still enough. At present, this solar panel is not yet able to charge the high-voltage battery, but Mercedes-Benz is working in this direction.

Equipping the roof with solar cells is not the original of Mercedes-Benz, before which such as Toyota bZ4x, GAC Aehan S can be equipped with solar cells on the roof. However, the application of solar cells in electric vehicles is the first to solve the cost problem.

Integrate energy savings into every corner of the carriage

Mini-LED all-in-one screen

EQXX's 47-inch 8k all-in-one interior screen is also a big energy consumer, but it uses mini-LED technology, and the display area is composed of more than 3,000 local dimming areas. Like OLED, it is a self-illuminating display element, which means it consumes power only when specific parts of the screen are needed.

The information processing behind the screen is also exquisite, and it uses a neuromorphic network computing technology. The information is encoded in discrete spikes that consume energy only when spikes occur, reducing energy consumption by several orders of magnitude. Mercedes-Benz engineers worked with California-based artificial intelligence expert BrainChip to develop the system based on BrainChip's Akida hardware and software.

EQXX's voice system applies this technology, which only triggers when it detects the "Hey Mercedes" keyword, consumes energy for calculations, and does not need to keep running in the background, which is five to ten times more energy efficient than traditional voice control.

EQXX's sound is also exquisite, Mercedes-Benz engineers reduced the total number of speakers and placed them very close to the passengers, such as headrests and seats, thereby shortening the propagation distance of the sound waves and reducing the attenuation caused by the reflection and absorption of sound waves on the surface of the cabin. This optimizes the sound experience while minimizing energy consumption. At the same time, the layout close to the occupant makes it easier to convey the cue to the driver via audio.

Finally, to sum up, at present, there are two models in the world that have achieved a range of 1000 kilometers, GAC Aion LX and Mercedes-Benz EQXX. They represent the two directions of electric vehicle endurance development, open source and throttling. The Aion LX's battery life relies on the largest 144-degree battery in its production passenger cars. The insertion of a larger capacity battery pack in a body of the same size reflects the advancement of battery material technology.

The core of EQXX's 1000 km endurance is to reduce losses, and its main technologies include: low wind resistance, low rolling resistance tires, high energy density batteries, lightweight body brought by new materials, multi-source heat pumps, high-efficiency electric drive assemblies and roof solar cells.

Many of these technologies can be delegated to mass production vehicles, and although the remaining part cannot be directly applied to mass production vehicles due to cost and practical considerations, they play an exploratory significance, and the auxiliary tools developed in the development process (such as software in the ring SiL, etc.) are important references for future automobile research and development.

This article is written by The Kickbox Gang Route 64