In-depth analysis: Volkswagen's standardized battery cell, from winding to stacking flat pouch.

Author: Zhu Yulong

There have been some doubts about Volkswagen’s battery production. Recently, the groundbreaking ceremony for Volkswagen’s first European battery factory, located in Salzgitter, Germany, has taken place. The entire investment is approximately 2 billion euros, with plans to begin production in 2025. At full capacity, the factory will be able to produce 40GWh of power batteries, supplying 500,000 electric vehicles. During the groundbreaking ceremony, Volkswagen introduced the concept of a standard factory and also showcased the new-generation Unified battery cell definition. As Chinese technology develops, the definition of European batteries is also rapidly adjusting, quickly transitioning from the traditional winding method to the new method, which combines the characteristics of soft-package and box-shaped batteries. The blueprint for Volkswagen’s 6 European battery factories will be managed by the newly established company, PowerCo, which will also be responsible for the entire value chain of power batteries. Alongside its partners, PowerCo will invest more than 20 billion euros in the development of the power battery business, with an expected annual sales revenue of over 20 billion euros.

In the future, Europeans will establish barriers such as raw material carbon footprint, battery recycling, and reutilization. We will find that, based on the advantageous industrial chain in China, other countries have some unique ways of overtaking on the bend, and we need to consider this.

In the era of high penetration of electric vehicles, batteries are the cornerstone of automakers. Volkswagen’s original words are: Sebastian Wolf, Volkswagen’s battery operation director, said, “In the case of battery cells, we are nothing more than fast followers at the moment, but if we do things right, we can be among the leaders in a number of years.”

▲Figure 1. Volkswagen's Standardized Battery and Standardized Factory

Volkswagen Standardized Battery Cell

In contrast to many comrades who are optimistic about China’s evolution route, the core difference after choosing cylindrical, soft-package, and box-shaped batteries lies in the usage state of the battery cell on the car. As weight and energy density no longer have the significance of subsidizing hard thresholds, future development requires a shift from battery cell cost and manufacturing efficiency to battery cell efficiency in vehicle space utilization.

Therefore, at Battery Day, we still see Volkswagen choosing the box-shaped battery cell of MEB 590. With this release, we see the box-shaped battery cell with double ends.▲Figure 2. Volkswagen Unified Battery Cell Conversion

The following figure is more direct, showing the evolution process.

▲Figure 3. Volkswagen Unified Battery Cell Conversion

The specific specifications can be found in the data of Guoxuan High-Tech Environmental Assessment. The dimension of the cell is 25610624.8, where 256mm is the width, corresponding to the direction of the tab. 106mm is the height, which is significantly higher than the cell shoulder height with tab. 24.8mm is the thickness, which is generally adopted from the square shell battery.

In this design, we can see that the energy density for the ternary version is 425Wh and for the lithium iron phosphate version is 294Wh. The corresponding energy densities are 265Wh/kg and 190Wh/kg, and the volume energy densities are 630Wh/L and 435Wh/L.

Designs with charging rates of 2C and 3C are available.

▲Figure 4. Volkswagen Standard Battery Cell Specifications

From the design perspective, the core logic is a judgment based on a proportion, where battery factories with projecting tabs in the Z-direction are not top-tier in terms of level, with the exception of the 4680 cylindrical cell, which is excellent in terms of electrochemical systems and standardization.

▲Figure 5. The Underlying Logic of Volkswagen's Transformation

From a cost perspective, Volkswagen is very optimistic about the cost reduction brought by this blade battery.

▲Figure 6. Volkswagen's Judgment on Products

Barriers to Battery Cell Manufacturing

From all aspects, the core needs for Volkswagen in building multiple battery factories are:

Strong team: Volkswagen has also established a base in the United States and is looking for top international experts in the battery industry to continue to expand its team.

Suitable partners: The construction and operation of battery factories.### Standardization

If individually planning each factory’s budget takes too much time, the concept of a standard factory is used to maintain adaptability and flexibility. Standard design simplifies and speeds up planning and procurement, and all factories use identical components for buildings and equipment (approval processes vary in different countries). The foundation of the standard factory is Volkswagen’s unified unit, which brings high economies of scale.

▲Figure 7. Volkswagen's 240GWh factory

At present, the first 50GWh factory is indeed likely to collaborate with Northvolt or Guoxuan High Tech. The former has a better winding shell, while the latter was initially given the route of soft pack stacking.

▲Figure 8. The first 50GWh factory

A careful analysis of this battery factory shows that it is like a complex, a place where Volkswagen gathers talents to build batteries, and you can see that it encompasses not only manufacturing, but also all aspects.

▲Figure 9. Volkswagen is serious in dealing with batteries

Summary

At a 10% penetration rate, each automaker can buy batteries; at 25%, it becomes difficult to acquire batteries and prices are no longer controllable, making it a burden for OEMs to have large procurement demands. When the penetration rate reaches 50% and 100%, what should automakers do? Everyone can imagine it.

This article is a translation by ChatGPT of a Chinese report from 42HOW. If you have any questions about it, please email bd@42how.com.