Background

With the rapid growth of the number of new energy vehicles, the demand for the regeneration and utilization of retired blade batteries has become increasingly urgent. Due to the size of blade batteries (up to 2500mm in length) far exceeding traditional square shell batteries and their higher energy density, this poses new challenges to the feeding and crushing processes of existing battery powder lines, prompting the industry to upgrade related process technologies.

Core challenge

At present, mainstream battery recycling production lines are designed with a processing specification of only 350mm for the longest end of square shell batteries. However, the size span of BYD’s retired blade batteries is extremely large, with the longest end range extending from 435mm to 2500mm. This difference directly highlights two core shortcomings of the current process:
Firstly, the size adaptability is severely lacking. The traditional feeding system is simply unable to accommodate blade batteries with a length exceeding 2000mm, resulting in the batteries being unable to enter the crushing process smoothly, and the frequent occurrence of “shell jamming” in the production line, seriously affecting the continuity of the production process.
Secondly, the security risks have significantly increased. Due to the higher energy density of blade batteries, once a short circuit occurs during the crushing process, the temperature rise rate will sharply increase, and the probability of causing heat loss, smoke, or even fire is much higher than that of ordinary batteries. However, the safety protection capabilities of traditional crushing processes are difficult to match, which poses great risks to production safety.

Upgrading direction of process technology

Feeding process: customized innovation, smooth delivery of large-sized batteries
The traditional fixed size feeding port can no longer meet the feeding requirements of large-sized blade batteries. We boldly abandon this design and introduce a “special feeding device” with adjustable width. Through the flexible expansion and contraction of the mechanical structure, this device can easily handle the smooth transportation of blade batteries with different lengths ranging from 435mm to 2500mm, effectively avoiding pre damage caused by compression and collision during the feeding process, laying a good foundation for the smooth development of subsequent processes.

Crushing process: pre crushing support, safety upgrade
Faced with the safety challenges of blade batteries, the traditional “one-step crushing” process seems inadequate. We have added a ‘pre crushing process section’, which first disassembles the large-sized blade battery into short sections before entering the subsequent crushing process, greatly reducing safety risks. The two types of pre rupture solutions in the industry each have their own characteristics:

Option 1: Four shaft crushing (nitrogen protection+oxygen and temperature control)
By using a nitrogen environment to suppress oxidation reactions and controlling oxygen and temperature to reduce the temperature rise during crushing. However, in actual operation, there are frequent occurrences of severe deflation and smoking of blade batteries, and safety hazards still exist.

Option 2: High speed shear crushing (with special feeding coordination)
Combined with a customized feeding device, the long battery is precisely cut into short segments using high-speed rotating cutting tools. This crushing method is gentler and significantly improves the safety factor, undoubtedly making it the current better technological choice.

Conclusion

The recycling of retired blade batteries is not only a key link in achieving the “dual carbon” goal, but also an important support for the closed-loop of the new energy industry chain. In the selection of process technology, it is necessary to always prioritize “safety” over efficiency and effectiveness, and solve the processing problems of large-sized and high-energy density batteries through pre breaking process upgrades and feed system modifications.