Battery Electrode Folded Current Collector Lead Connection
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Solution Overview
Problem
Lithium-ion secondary batteries experience electrode distortion and capacity decrease due to separation of active materials from current collectors, leading to variations in reactions caused by unequal electrode intervals during the connection of electrode terminals and current collector exposed portions.
Innovation Solution
A battery design featuring a current collector folded region where the electrode lead is connected, reducing the thickness difference between the active material coated and exposed portions, thereby minimizing distortion and maintaining even electrode intervals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the current collector exposed portion is gathered to be in contact with the electrode terminal, then the connection between electrode terminal and current collector is achieved, but large distortion is caused in part of the electrode
Solution Approach 1:
The current collector exposed portion is folded in advance before connection to the electrode terminal. This preliminary folding action prepares the current collector in a pre-positioned state that eliminates the need for gathering during assembly, thereby preventing electrode distortion while maintaining connection ease.
Solution Approach 2:
The current collector is divided into distinct functional regions: an active material coated portion and a current collector exposed portion. The exposed portion is further segmented into a folded region that is specifically dedicated to terminal connection, separating the connection function from the active material region and preventing distortion.
2Reliability
If parts of the current collector exposed portion are gathered to contact the electrode terminal, then electrical connection is established, but capacity decrease occurs due to separation of active material from current collector
Solution Approach 1:
The current collector exposed portion is folded beforehand to create a stable connection structure. This preliminary action ensures reliable electrical connection without requiring gathering operations that would cause active material separation, thereby preserving battery capacity.
Solution Approach 2:
The current collector is segmented into an active material coated portion and a current collector exposed portion with a folded region. This segmentation isolates the connection function to the exposed folded region, preventing mechanical stress from transferring to the active material and avoiding capacity loss.
3Ease of manufacture
If the current collector exposed portion is gathered for terminal connection, then connection is achieved, but variations in reactions occur due to unequal electrode intervals
Solution Approach 1:
The current collector exposed portion is folded in advance to establish a predetermined geometry. This preliminary folding creates uniform electrode intervals from the start, ensuring consistent reaction conditions throughout the battery while maintaining easy terminal connection.
Solution Approach 2:
The current collector is divided into functional segments including a folded region for connection. This segmentation ensures that the connection operation occurs in a dedicated region that does not affect the uniformity of electrode intervals in the active material regions, maintaining reaction stability.
Data Source
AI summary
To provide a battery in which electrode distortion is suppressed in connecting an electrode terminal and a current collector exposed portion. The battery includes an electrode, an exterior body surrounding the electrode, and a lead extending from the inside to the outside of the exterior body. The electrode includes a current collector and an active material layer. The electrode includes a first region where the active material layer is provided over the current collector, and a second region where the current collector is exposed. The second region of the electrode includes a third region where the current collector is folded. The lead is connected to the electrode in the third region.