Secondary Battery Electrode Lamination With Thermal Aging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The manufacturing method for secondary batteries faces a challenge in balancing process performance and battery performance, as strong lamination improves bonding strength but can lead to defects, while weak lamination results in reduced separator bonding strength and battery deterioration.
Innovation Solution
A method involving the lamination of an electrode assembly at a pressure of 5 kgf/cm² or more, followed by high-temperature aging of the preliminary battery at 60°C to 100°C for 1 to 6 hours, which includes charging, discharging, and a degassing process to enhance ion conductivity and prevent battery degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If lamination is strengthened to improve bonding strength between electrode and separator, then process performance is improved, but battery performance is deteriorated
Solution Approach 1:
The patent applies parameter changes by modifying the lamination pressure from conventional high pressure (10-20 kgf/cm²) to a lower range (5-15 kgf/cm²), and by introducing a specific thermal treatment process (aging at 60-100°C for 1-6 hours) to achieve optimal bonding strength without compromising battery performance. This resolves the contradiction by finding an optimal parameter range that satisfies both process performance and battery performance requirements.
2Reliability
If lamination is weakened to maintain battery performance, then battery performance is maintained, but bonding strength between electrode and separator is reduced causing defects
Solution Approach 1:
The patent applies preliminary action by performing thermal treatment (aging) at 60-100°C for 1-6 hours after lamination. This preliminary thermal treatment enhances the bonding strength between electrode and separator, allowing the use of lower lamination pressure (5-15 kgf/cm²) while still achieving sufficient bonding strength and maintaining battery performance. The thermal treatment compensates for the reduced mechanical bonding from lower pressure lamination.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach significantly increases bonding strength between the electrode and separator, improves ion conductivity, and extends the battery's lifespan by reducing concentration polarization resistance and open circuit voltage, thereby enhancing both process and battery performance.
Implementation Method 1
a step (b) of laminating the electrode assembly at a pressure of 5 kgf/cm 2 or more
Implementation Method 2
a step (e) of thermally treating the preliminary battery by aging the preliminary battery at a high temperature
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method for manufacturing a secondary battery according to the present invention comprises: a step (a) of alternately stacking an electrode and a separator to manufacture an electrode assembly; a step (b) of laminating the electrode assembly at a pressure of 5 kgf/cm2 or more to bond the electrode and the separator, which are provided in the electrode assembly, to each other; a step (c) of accommodating the electrode assembly in a battery case and injecting an electrolyte into the battery case to seal the battery case, thereby manufacturing a preliminary battery; a step (d) of charging and discharging the preliminary battery to activate the preliminary battery; and a step (e) of aging the preliminary battery at a high temperature of 60°C to 100°C for 1 hour to 6 hours to thermally treat the preliminary battery.