Pouch Cell Formation Sequence to Limit Deformation and Restore Capacity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing secondary battery manufacturing processes face issues such as yield decrease, physical deformation, and reduced energy density due to the characteristics of anode active materials like silicon-based materials, leading to structural imbalances and decreased efficiency.
Innovation Solution
A method involving inserting an electrode assembly into a pouch, injecting electrolyte, aging, degassing, discharging gas, and charging to a shipment voltage, with a CC/CV discharging method to prevent deformation and improve capacity prediction, omitting additional charging steps post-degassing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If additional charging process is performed after degassing, then capacity can be restored, but manufacturing time increases and process complexity increases
Solution Approach 1:
The patent extracts and eliminates the unnecessary additional charging process from the manufacturing sequence. By analyzing the actual needs, it determines that degassing alone suffices to restore battery capacity, removing the redundant charging step that only added time and complexity without providing additional benefit.
Solution Approach 2:
The patent performs capacity restoration through degassing as a preliminary action before final assembly, rather than requiring a subsequent charging step. This preliminary degassing action adequately prepares the battery for use, eliminating the need for post-degassing charging.
2Quantity of substance
If electrode assembly is compressed during charging, then energy density increases, but physical deformation occurs
Solution Approach 1:
The patent changes the timing parameter of compression from 'during charging' to 'before charging'. By compressing the electrode assembly prior to the charging process, it achieves the desired density without subjecting the compressed structure to additional expansion forces during charging, thereby preventing physical deformation.
3Productivity
If charging current is increased to reduce manufacturing time, then productivity increases, but heat generation increases causing safety issues
Solution Approach 1:
The patent converts the potential harm of heat generation into a benefit by implementing controlled heating during the degassing phase. The heat generated during degassing is utilized to facilitate gas removal and electrode activation, turning what would be a safety concern into a useful process aid that reduces the need for high-current charging.
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 method reduces thickness variation, enhances manufacturing reliability, and increases energy density by minimizing physical deformation and heat generation, allowing for precise assembly and improved energy efficiency.
Implementation Method 1
when the secondary battery is charged, a charging current flows as metal atoms move from the cathode to the anode through the separator. Conversely, when the secondary battery is discharged, a discharging current flows as the metal atoms move from the anode to the cathode
Implementation Method 2
discharging is the movement of electrons from the high-voltage anode to the low-voltage cathode (electricity is generated as much as the voltage difference between the cathode and anode), and charging is the movement of electrons from the cathode to the anode
Implementation Method 3
injecting an electrolyte into the pouch and performing ageing
Data Source
AI summary
Proposed is a method of manufacturing a secondary battery. The method includes inserting an electrode assembly into a pouch, injecting an electrolyte into the pouch and aging, charging the electrode assembly, degassing to discharge gas from the pouch, discharging the electrode assembly, and charging to a shipment charge level. Since an anode active material is added to an anode material of a secondary battery through the method, there is an effect of further enhancing the reliability of the secondary battery in the manufacturing method of the secondary battery.