Vincent Sergère's visit to BYD's factory

Vincent Sergère visited a factory belonging to FinDreams Battery (Fudi), a subsidiary of BYD, located in Qiaotou, Yongjia district, north of Wenzhou. The factory, which began construction in early 2023, is part of a major investment plan with an initial capacity of 20 GWh per year.

Factory's strategic location and expansion

The factory is one of many FinDreams Battery sites across China, illustrating BYD's strategy of producing its own batteries instead of relying on external suppliers. The site is part of a broader network that spans from Chongqing to Xi'an and beyond.

Anode coating process

The journey through the factory begins with the anode coating line, where an automated system removes metal impurities from the electrode paste. The process involves applying a thin layer of graphite onto copper sheets, which are then dried in large ovens.

Calendering and precision

After drying, the anode strip undergoes calendering, where it is compressed between massive rolls to ensure a uniform thickness. This is a critical step, as uneven thickness can lead to uneven aging of the battery cell. BYD claims a precision of 2 microns in thickness.

Cutting and stacking

The coated anode strip is then cut into precise dimensions using a slitting line. This is followed by the stacking process, where the Blade Battery's unique design—made of stacked layers rather than rolled—requires meticulous alignment and precision to ensure optimal performance and safety.

Welding and assembly

The next stage involves welding the electrode tabs to the cell's terminals using ultrasonic or laser techniques. This is crucial for managing high charging speeds, as the Blade 2.0 battery can handle up to 1,500 kW of power. The rest of the assembly, including electrolyte injection, takes place off-site.

Blade Battery 2.0 features

Sergère observed the new Blade Battery 2.0, which offers improved energy density and faster charging times. It can charge from 10 to 97% in nine minutes and is optimized for extreme temperatures. The battery's design includes advanced materials and a redesigned SEI layer for better performance.

Production challenges and quality control

Despite its advanced features, producing the Blade 2.0 in volume has been challenging for BYD, with reports of production delays. Quality control is strict, involving formation of the battery, aging, and individual testing before cells are integrated directly into vehicles without traditional modules.

Testing new models

After the factory visit, Sergère tested the new off-road models of Fang Cheng Bao and Yangwang. Fang Cheng Bao, a brand launched in 2023, has seen significant growth, driven by models like the Tai 7, which uses the Blade Battery 2.0.