The 150kWh NIO ES6 is ground breaking for a number of reasons and perhaps 260Wh/kg at pack level is not the most significant.

- Total energy = 150kWh
- Usable energy=136.7kWh
- SoC Window = 91.1%
- Nominal Voltage = 340 V
- Voltage range = 408V to 240V
- Nominal Capacity = 446Ah
This post has been built based on the support and sponsorship from: About:Energy, AVANT Future Mobility, Quarto Technical Services, TAE Power Solutions and The Limiting Factor.
NIO chairperson and CEO has shared the ES6 will be able to garner 930 km (577 miles) of range on a single charge with the 150 kWh pack. 930km range and an energy consumption of 147Wh/km [2] for the 100kWh version that is 20kg lighter gives a usable battery pack energy of 136.7kWh.
The pack capacity of 446Ah as given by reference 1 doesn’t match the cell capacity of 110Ah and 4 cells in parallel
- Configuration = 96s 4p
- Pack Mass = 575 kg
- Cell Mass = 416 kg
- Pack-Cells = 159 kg
- Cell to Pack Mass Ratio = 72%
- Pack Dimensions = 2062 x 1539 x 185.6 mm
- Pack Volume = 589 litres

The 159kg mass of the pack when you remove the cells for a 150kWh pack is remarkably good.

Plotting volumetric density versus gravimetric density we see that NIO battery packs are not well packaged with respect to volume.
The Mercedes EQXX leads on volumetric density by a considerable margin.
Charging
With a nominal pack voltage of 337V the fast charge rate will be limited by the maximum current for the charging system.
- 20 to 80% in 40 minutes
NIO have a battery swap system that allows customers to recharge rapidly and to swap between pack energy capacities. Pack swapping is an interesting way of launching a new battery technology and giving customers confidence.
Cell
The cell is described as a semi-solid state cell from WeLion.

- Nominal Capacity = 110 Ah
- Nominal Voltage = 3.55 V
- Nominal Energy = 390Wh
- Mass = 1.083 kg
Metrics
- Gravimetric Energy Density = 261 Wh/kg
- Cell = 360Wh/kg
- Volumetric Energy Density = 255 Wh/litre
Perhaps more remarkable is the fact that these cells were only coming off the production line at the end of 2022, for a new cell this is a remarkably short time to vehicle launch.
References
- NIO’s 150-KWh Battery Pack Reveals Its Secrets Ahead of Schedule in New Owner’s Manuals, autoevolution
- 2019 NIO ES6 Specs, Range, Performance, ECARSRANGE.com
- NIO finally adds its solid-state battery to user manuals, arrival of 930 km range option imminent, electrek
- Jerry Wan, Welion 360Wh/kg Solid State Battery Analysis, LinkedIn