NIO has officially launched today an all-new 75 kWh standard-range, hybrid-cell battery pack, which replaces the previous 70 kWh battery option (NCM). Orders are accepted now, while customer deliveries will start in November.
The "hybrid-cell" is just a marketing name, as there are no hybrid cells - the battery pack is a hybrid that consists of two different lithium-ion battery cell chemistries: NCM (nickel:cobalt:manganese) and LFP (lithium iron phosphate). The ratio of NCM/LFP was not disclosed (we guess that it might be simply 1:1 or 2:1).
The purpose of combining the two types is to enhance the overall parameters of the battery. The NCM cells are known for their high energy density, while the LFP is the least expensive.
The new hybrid-cell battery also has no battery modules as NIO applied its new-generation cell-to-pack (CTP) technology. That simplifies production, reduces costs and additionally improves energy density.
The results are pretty interesting, as the company is now able to offer a 75 kWh at a price of the outgoing 70 kWh version, which increases the range of ES8, ES6 and EC6 cars by at least several percent.
NIO standard-range, hybrid-cell battery pack stats:
- 75 kWh (5 kWh or 7% more than 70 kWh previously)
- battery cell chemistry: NCM and LFP
- NCM/LFP ration: N/A
- cell-to-pack (CTP) technology (no modules)
- simplified manufacturing and assembly by 10%
- increased volume utilization by 5%
- increased energy density by 14% to 142 Wh/kg
One might ask why not switch to all-LFP battery if it's less expensive. Well, the energy density would be lower and there are other issues with the LFP chemistry like lower capacity and performance in cold weather and not as accurate estimation of the state-of-charge (SOC) due to the mostly flat voltage curve.
NIO says that it addressed the low-temperature issues through software and hardware solutions.
"NIO has designed a complete thermal management software and hardware system for the standard-range battery (75 kWh), which reduces the range loss in low temperature by 25% compared to its LFP counterpart."
"The comprehensive environment shielder applies low-thermal conductivity materials and innovative structural design for the source of heat loss in extremely cold environments in order to effectively improve passive thermal insulation performance.
The intelligent thermal system coupling battery heat generation dynamically adjusts thermal control targets in combination with battery heat to balance the drive experience and energy consumption. The radiant thermal compensation heater uniformly heats the battery cells to maintain the working temperature of the battery while taking into account the energy consumption.
The hybrid layout of ternary lithium cells and LFP cells makes full use of the low-temp performance advantage of ternary lithium cells to improve the overall battery performance in low temperature. And the dual chemistry control algorithm precisely controls the performance of ternary lithium and LFP cells in cold temperature to improve low-temp energy efficiency of the whole battery system.
The LFP's SOC estimation accuracy has been improved too so it's now at the level of NCM type.
"NIO’s self-developed hybrid-cell battery SoC estimation system integrates the innovation of software algorithm and hardware application, which reduces the estimation error to less than 3%, reaching the level of ternary lithium battery SoC estimation. The dual chemistry SoC algorithm fully takes advantage of ternary lithium and LFP battery systems to realize constant battery SoC estimation and guarantee the accuracy. A high-power DCDC within the battery ensures fast, real-time and balanced SoC calibration"
More hybrid batteries in the future?
As of now, the 100 kWh battery version remains 100% NCM 811, but we guess that it might also switch to a hybrid at some point in the future.
As long as the LFP battery is significantly less expensive than the NCM, a hybrid solution that would not affect the overall battery parameters too much is interesting.
According to the media reports from China, in September NIO applied for MIIT production/sales license for the NIO ET7 model (the upcoming flagship), also equipped with a hybrid battery.
As far as we know, NIO uses lithium-ion cells from CATL, which recently proposed a hybrid battery pack - CATL AB - specifically for its new sodium-ion batteries (but it might be any cell chemistry combination).
We would not be surprised if the latest NIO battery is the fruit of a joint partnership with CATL. The overall design approach looks similar.