Lithium-ion Battery Winding Process Guide

1. Material confirmation

Potential risks

It is necessary to confirm whether the length, width and thickness of the electrode meet the process standards

Poor jelly roll coverage, size does not meet requirements

It is necessary to confirm whether the length, width and thickness of the diaphragm meet the design specifications

Jelly roll size does not meet requirements, finished battery performance affected

It is necessary to confirm whether the type and size of the winding needle meet the process requirements

Battery deformation, jelly roll size does not meet requirements

It is necessary to confirm whether the termination tape meets the process requirements

Jelly roll thickness and appearance unqualified

2. Parameter confirmation

Potential risks

It is necessary to confirm whether the winding speed meets the process requirements and record it

Electrode broken and battery deformation

It is necessary to confirm whether the tension of the positive and negative electrodes is too large and record it

Electrode broken and battery deformation

It is necessary to confirm whether the tension of the diaphragm is too large and record it

Battery deformation

3. Confirmation of the appearance and size of the jelly roll

Potential risks

It is necessary to confirm whether the inner and outer layers of the jelly roll are aligned

Internal short circuit, poor packaging

It is necessary to confirm whether the height of the tab glue meets the design requirements

Poor packaging, unqualified size

It is necessary to confirm whether the height, width and thickness of the jelly roll meet the process standards

Cannot be put into the shell, unqualified appearance, finished battery size exceeds the standard

It is necessary to confirm whether the tab margin and center distance meet the design requirements

Poor packaging, unqualified size, affecting use

It is necessary to confirm whether there is a possibility of contact between the negative electrode and the aluminum-plastic film layer

Al layer is corroded, battery leakage, flatulence

Disassembling the battery, it is necessary to confirm whether the end position of the electrode is correct

Unqualified size, internal short circuit

When disassembling the battery, it is necessary to confirm whether the diaphragm and the negative electrode, and the negative electrode and the positive electrode are completely covered

Low capacity, lithium deposition, internal short circuit

Disassembling the battery, it is necessary to confirm whether the positive electrode, negative electrode, and diaphragm are wrinkled

Poor battery interface, lithium deposition

Disassembling the battery, it is necessary to confirm whether the first fold of the positive electrode and the negative electrode are broken or transparent

Large battery internal resistance, low capacity

Disassembling the battery, it is necessary to confirm whether there is contact between the exposed Al foil and the negative electrode material

Poor safety performance