- Mercedes' latest concept offers an advanced look at AMG's forthcoming high-performance electric sedan.
- It's axial flux motors offer 3 times the power density of conventional electric motors while also being lighter.
- New battery tech promises super-fast charging and maximum performance.
Mercedes-AMG has unleashed it's take on a high-performance electric sedan with the reveal of the Concept AMG GT XX, a "technology program" that provides insight into the forthcoming four-door series-production sports car.
The Concept AMG GT XX features an advanced drive concept that incorporates three axial flux motors and a newly developed high-performance battery. Mercedes says the motors are integral to the GT XX's performance, offering a power density approximately three times that of conventional electric motors. They are also about two-thirds lighter and occupy only one-third of the space, allowing for more flexible drivetrain packaging.
In an axial flux motor, the electromagnetic flux runs parallel to the motor’s axis of rotation, differing from conventional electric motors where it runs perpendicularly. This design facilitates slim, disc-shaped components, with the stator positioned between two rotors.
The vehicle's system output exceeds 1000kW and the motors are integrated into two "High Performance Electric Drive Units" (HP.EDUs): one at the front and one at the rear. The rear HP.EDU contains two axial flux motors, each with a planetary gearset and an inverter, all housed in a single, oil-cooled casing. The inverters are water-cooled and utilise silicon carbide for high-voltage, high-current applications.
The front HP.EDU includes one axial flux motor, a spur-gear transmission and an inverter, and functions as a booster, engaging when additional power or traction is needed at the front wheels. The front HP.EDU can be decoupled by a Disconnect Unit (DCU) to reduce drag and enhance efficiency during steady driving or low load.
The technological foundation for the axial flux motors was initially developed by YASA, a Mercedes-Benz AG subsidiary, while the concept was further refined in collaboration between Mercedes-AMG and YASA for its application in the Concept AMG GT XX and future series production.
Production of these axial flux motors will occur at the Mercedes-Benz plant in Marienfelde, Berlin. The manufacturing process involves approximately 100 steps, with about 65 being new for Mercedes-Benz and 35 being newly developed globally, incorporating laser technology, joining processes, and artificial intelligence. These innovations have led to over 30 patent applications.
The high-voltage battery in the Concept AMG GT XX is also a new development, leveraging experience from the AMG ONE and Formula 1, alongside engineers from Mercedes-AMG and Mercedes-AMG High Performance Powertrains (HPP).
The company says the "High Performance Electric Battery" (HP.EB) is designed for high power output with consistent repeatability, fast energy absorption, and high power density. Its performance is supported by new battery cell developments, direct cell cooling, and a high voltage system.
The battery uses cylindrical cells that are tall and slim, a design chosen for effective heat dissipation due to the small distance from the cell core to the casing. The cells are enclosed in a laser-welded aluminium housing, which is lighter and offers improved electrical and heat conductivity than traditional steel containers, aiding in precise thermal control.
The cell chemistry is a specific NCMA (nickel/cobalt/manganese/aluminum) cathode with a silicon-content anode. Mercedes says this combination provides an energy density of 300Wh/kg, robust charging performance, and a long lifespan.
Direct cooling is integrated into the laser-welded plastic modules that house the cells, and an electrically non-conductive oil coolant flows around each of the more than 3000 individual cells, ensuring optimal temperature maintenance.
This system, combined with the cell design, supports high sustained power density. The battery operates at a high voltage of more than 800 volts, contributing to overall performance by allowing lighter cabling, higher continuous power output, and reduced charging losses.
The Concept AMG GT XX features rapid charging capabilities, allowing it to recharge enough energy for approximately 400 kilometres of range in about five minutes, and achieves a high average charging power of more than 850kW.
Mercedes-Benz says it has collaborated with high-power charging specialist Alpitronic to develop a prototype charging station capable of transmitting such high current via a standard CCS cable, and the company plans to expand its charging network with next-generation stations to support very fast charging times that are comparable to conventional refuelling.
Aerodynamic efficiency has been a significant focus with the development of the Concept AMG GT XX, and it achieves a low drag coefficient of 0.198, despite its wide high-performance tyres. The underbody has a specially developed contour that creates a Venturi effect to reduce lift at the rear without significantly impacting the drag coefficient.
Aerodynamics also support cooling functions, with a passive cooling plate at the front of the underbody and an active air control system that manages airflow through louvers behind the front bumper's air intake, optimising the balance between cooling and aerodynamic drag.
The interior design is simplified, resembling a racing car, with a focus on technical elements. It features two integrated, ergonomically angled LCD displays: a 10.25-inch instrument cluster and a 14-inch multimedia touchscreen, while the steering wheel is rectangular, inspired by motor racing, with paddles for recuperation control and LEDs indicating charge state and performance.
A distinctive interior feature is the exposed extrusions of the body-in-white around the centre console, illuminated with orange pipes, visually suggesting high-voltage cables.
For weight savings, the carbon-fibre bucket seats in the rear are integrated into the rear bulkhead, and the roof has no headliner, exposing the carbon-fibre structure. The floor covering is made from 100 percent recycled materials with a motorsport-inspired checkered flag design.
The Concept AMG GT XX incorporates innovative, biotechnology-based "Labfiber" materials. This includes a "Biotech Leather Alternative", developed with US bio-design start-up Modern Meadow. This material is made from recycled rubber, vegetable proteins, and biopolymers, with pyrolysis oil from used AMG GT3 racing tyres forming a base.
One scrap tyre can yield approximately four square meters of this material, and it aims to mimic leather's characteristics while being breathable, waterproof, lighter, and having twice the tensile strength of genuine leather. It can also be fully recycled.
The vehicle includes luminescent paint segments on its flanks, utilising electroluminescence technology to emit light in response to an alternating current. Mercedes says these segments are for visual effect at night and also communicate the charging status.
Another innovation is the integration of external speakers into the front headlights, using the headlight housing as a loudspeaker cavity. This design saves space, reduces weight, enables new sound variants, and serves for pedestrian protection.
At the rear, the MBUX Fluid Light Panel packs more than 700 freely programmable RGB LEDs, enabling active communication with the outside world through a 3D-pixel look. This panel can display real-time vehicle information as text or animations, such as the digital AMG logo or charging progress.
Even the humble wheel hasn't escaped AMGs' drive for innovation at any cost, with the 21-inch forged aluminium wheels packing active aerodynamic elements, namely five movable blades that can seal the wheel to reduce air resistance and improve range, or open to pump cooling air to the brakes and out of the wheel arch, enhancing brake cooling and vehicle aerodynamic downforce.
Each wheel's central actuator is an autonomous unit that generates its own electrical energy via a mini-generator from the spinning wheel, communicating wirelessly with the vehicle's control unit.
Mercedes-AMG boss, Michael Schiebe, said the new performance battery delivers a previously unimagined level of performance and endurance, while the axial flux motors offer a "revolutionary new drive that is unparalleled in terms of power density, weight and packaging."
"The Concept AMG GT XX is the next milestone in the history of AMG and forges a whole new dimension of performance. We’re bringing groundbreaking technology that redefines high performance. And the best thing is that this car is a true AMG with every fibre of its being," said Schiebe.
