What is the difference between repair and rework in lithium-ion battery manufacturing?

In the manufacturing of lithium-ion batteries, rework and repair are two different methods for handling non-conforming products, with the main differences being the processing objectives, methods, and impact on product specifications.

1. Rework

definition:

Repair is the process of partially correcting batteries with minor defects to restore them to their original design specifications and meet factory standards.

characteristic:

Do not change the design: only repair process or material issues (such as poor welding, electrode alignment deviation).

No need for re certification: The repaired product still meets the original performance and safety standards.

The process is simple: it usually involves local adjustments (such as re welding, fluid replenishment, and re packaging).

Example:

When the electrolyte injection volume is insufficient, replenish the electrolyte.

2. Rework

definition:

Rework is the deep treatment of severely defective batteries, which may require changes to the original design or specifications to meet secondary use or specific customer requirements.

characteristic:

Possible specification adjustment: The repaired product may not be completely consistent with the original design (such as capacity degradation, voltage adjustment).

Re evaluation is required: Additional testing or certification is needed to ensure compliance with the adjusted standards.

The process is complex: it may involve disassembling core components (such as replacing battery cells, reconstructing electrodes).

Example:

Batteries with insufficient capacity are downgraded for use in low-end product lines.

3. Summary of core differences and dimensions: Rework. The goal of rework is to restore to the original specifications, adjust to secondary specifications, or use special methods for local repair (process correction). Deep processing (possible replacement of core components). Compliance meets factory standards and does not require re certification. Re testing or certification may be necessary. Low cost/risk (quick repair). High (complex operations, potential performance changes)

Rework/repair requires strict adherence to operational standards, and the reworked/repaired batteries must undergo full inspection (such as internal resistance, capacity, and cycle testing), while reworked products may only be validated for specific indicators.

In general, repair is "restoring the original state", while rework is "transforming and utilizing". In battery manufacturing, both need to be executed with caution to ensure safety and reliability.

Don't confuse rework and repair when preparing documents or conducting actual operations on site.