Nio’s 925-volt electric motor, now used in several Nio and Onvo models, has been recognized with an engineering award. Its figures include a motor power density of 19.06 kW/kg, a controller density of 226.92 kW/L and peak power of 202.78 kW. The motor and controller measurements apply to those components separately, not to a complete drive unit that may also include a reducer, differential, inverter and housing.
The motor uses Nio’s W-Pin continuous-winding design rather than conventional hairpin windings assembled from separate copper pieces joined at their ends. Each winding starts with 12 flat copper strands, five metres long, which are precisely shaped through 24 bends. Nio’s engineers abandoned a method involving repeated 180-degree twists because it stretched the conductors and risked damaging their insulation. The alternative flat-forming process preserves insulation just 0.14 mm thick, while motor assembly tolerances are kept within 0.02 mm.
Nio tested the insulation through 1,300 hours of continuous high-temperature operation without a reported failure. Further tests included more than 500 hours simulating conditions at 5,500 metres, vibration up to 5.5 g across three axes, and over two months at temperatures from -40°C to +85°C. The motor’s windings and inverter semiconductors also help raise the voltage from lower-voltage DC chargers, avoiding a separate converter. The stated peak charging power is 202.78 kW, though actual output depends on the charger and operating conditions.