Curved Secondary Battery Hot Pressing for Spring-Back Compensation
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Solution Overview
Problem
Existing methods struggle to maintain the target radius of curvature of curved secondary batteries after activation due to the spring-back phenomenon, leading to inconsistencies in the final product's shape and capacity.
Innovation Solution
A manufacturing method involving two hot press steps is employed, where the first hot press sets the initial curvature and the second hot press adjusts the curvature to compensate for the spring-back effect, ensuring the final product maintains the target radius.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a single hot press step is performed to form the curved surface, then the manufacturing process is simple and fast, but the radius of curvature changes due to spring-back phenomenon after activation
Solution Approach 1:
The hot press process is divided into multiple sequential steps: a first hot press step to form an initial curved surface, followed by activation steps, and then a second hot press step to adjust and finalize the radius of curvature. This segmentation allows the manufacturing process to maintain productivity while achieving the required precision by correcting spring-back effects in subsequent steps.
Solution Approach 2:
The first hot press step performs a preliminary forming action to create the initial curved surface before activation. This preliminary action establishes the basic shape, and subsequent hot press steps after activation make final adjustments to compensate for spring-back, ensuring the final radius of curvature meets specifications.
2Loss of time
If the hot press is performed immediately after battery assembly, then the shape can be formed quickly, but the spring-back phenomenon causes the radius of curvature to deviate from target values
Solution Approach 1:
The manufacturing process employs periodic hot press actions separated by activation periods. The first hot press forms the initial shape, then activation occurs (including degassing and capacity confirmation), followed by a second hot press to adjust the radius of curvature. This periodic action pattern allows the battery structure to settle during activation while maintaining shape control through scheduled hot press interventions.
3Manufacturing precision
If multiple hot press steps are implemented to compensate for spring-back, then the radius of curvature precision is improved, but the manufacturing complexity increases
Solution Approach 1:
The process incorporates feedback through quality inspection after activation to determine whether a second hot press step is necessary. The inspection results feed back into the process decision-making, allowing the manufacturing system to adaptively apply additional hot press steps only when needed to correct spring-back deviations, thereby managing complexity while ensuring precision.
4Productivity
If the curved shape is formed before activation, then the manufacturing process is efficient, but the spring-back during activation changes the final shape from the target
Solution Approach 1:
The process applies beforehand cushioning by performing a second hot press step after activation to pre-compensate for and counteract the spring-back phenomenon. This anticipatory correction ensures that even though the shape changes during activation, the final product meets the target radius of curvature specifications.
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
The method effectively stabilizes the radius of curvature, ensuring the final product meets the target specifications by compensating for the spring-back phenomenon, thus achieving consistent shape and capacity.
Implementation Method 1
a hot press step is performed to have a target radius of curvature
Data Source
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AI summary
The present disclosure relates to a method of manufacturing a curved secondary battery having a target radius of curvature, the method comprising the steps of: (a) incorporating an electrode assembly including a cathode, an anode, and a separator interposed between the cathode and the anode into a battery case together with an electrolyte to manufacture a secondary battery; (b) subjecting the secondary battery to a first activation and degassing it; (c) subjecting the degassed secondary battery to a first hot press so as to have a first radius of curvature; (d) subjecting the secondary battery passed through the first hot press step to a second activation; and (e) subjecting the secondary battery passed through the second activation to a second hot press so as to have a second radius of curvature.