Roll-Core Winding Battery Cell for Lower Electrode Bending Stress
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Solution Overview
Problem
High-capacity and large-volume winding type battery cells face issues with electrode sheet deformation or fracture due to excessive bending stress, leading to active material loss and reduced performance.
Innovation Solution
A roll core is introduced to increase the winding radius of electrode sheets, reducing bending stress by separating positive and negative electrode sheets with a separator and connecting them to connection parts, thereby forming a winding type battery cell.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the number of winding turns of the electrode sheet is increased to improve capacity, then the capacity of the battery cell is improved, but the bending stress on the electrode sheet increases causing deformation or fracture
Solution Approach 1:
A roll core is introduced as an intermediary component around which the electrode sheet is wound. The roll core provides structural support and maintains a larger winding radius, thereby reducing the bending stress on the electrode sheet while still accommodating multiple winding turns to achieve high capacity.
Solution Approach 2:
The patent transitions from a traditional flat winding approach to a three-dimensional cylindrical winding structure around a roll core. This dimensional change allows the electrode sheet to be wound with a larger radius, reducing bending stress while maintaining multiple turns for high capacity.
2Quantity of substance
If the diameter of the battery cell is increased to improve capacity, then the capacity is improved, but the bending degree of the inner side of the electrode sheet increases causing deformation or fracture
Solution Approach 1:
The roll core acts as a mediator that distributes the winding stress evenly across the electrode sheet. By providing a cylindrical surface with optimized radius, it reduces the bending degree on the inner side of the electrode sheet while still allowing for increased cell diameter and capacity.
Solution Approach 2:
The patent optimizes the winding radius parameter by introducing a roll core with specific dimensional parameters. This parameter change allows the battery cell to achieve larger diameter for high capacity while maintaining the electrode sheet shape by controlling the bending degree through the roll core radius.
Data Source
AI summary
A winding type battery cell includes a roll core and at least one electrode sheet unit. The roll core includes a positive connection part, a negative connection part and an insulation part located between the positive connection part and the negative connection part. The positive connection part and the negative connection part are respectively connected with two ends of the insulation part. The electrode sheet unit includes a positive electrode sheet, a negative electrode sheet and a separator. The positive electrode sheet and the negative electrode sheet are separated by the separator. The positive electrode sheet is connected with the positive connection part, and the negative electrode sheet is connected with the negative connection part. The winding type battery cell is formed by winding the electrode sheet unit around the roll core. A winding battery with the winding type battery cell is also provided.