Nio’s 925-volt electric propulsion system has passed one million units produced and won the first prize in the 2026 China-SAE Science and Technology Progress Awards. The award was announced on October 28 and recognizes work by Nio, Tongji University, Harbin Institute of Technology and Baoshan Iron & Steel. The system entered mass production in December 2024 and is fitted to the Nio ET9, ES8 and ES9, as well as the Onvo L90 and L80.
A key element is Nio’s W-Pin stator winding, which uses 12 continuous, five-metre copper conductors shaped into 24 bends rather than many separate pieces joined by welding. The long, rigid wires are difficult to shape without damaging their insulation. Nio’s process forms them in a plane, controlling insulation thickness to 0.14 mm and motor assembly tolerances to 0.02 mm. The award also covers thermal integration and a charging approach that uses the motor windings and inverter to raise incoming DC voltage, avoiding a dedicated converter. The system is rated for up to 275.70 metric horsepower in this operation, depending on the charger and operating conditions.
Nio reports motor power density of 25.91 metric horsepower per kilogram and controller density of 308.53 metric horsepower per litre; these figures describe separate components, not complete drive units. Testing included 1,300 hours at high temperature, more than 500 hours under simulated conditions equivalent to 5,500 metres altitude, and exposure to vibration and temperatures from -40°C to +85°C. Nio says its propulsion development began in 2015 and has produced 146 authorized patents and contributions to six Chinese national automotive standards.