Leadtab Assembly With Elastic Bending for Electrode Expansion
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Solution Overview
Problem
Lithium secondary batteries experience breakage of the electrode non-coating portion due to expansion, leading to reduced capacity and increased resistance, which is not effectively addressed by existing technologies.
Innovation Solution
A leadtab assembly with an elastic structure, featuring an arched bending portion and insulation portion, is integrated to prevent bonding breakage by allowing deformation in response to electrode expansion, maintaining a stable current path.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the electrode non-coating portion is bonded to the leadtab, then the current path is established, but the bonding portion breaks due to electrode expansion
Solution Approach 1:
The leadtab structure is changed from a flat configuration to one including an arched bending portion with a predetermined curvature radius. This geometric parameter change allows the leadtab to deform elastically in response to electrode expansion, maintaining bonding reliability while preventing breakage at the bonding portion
Solution Approach 2:
The leadtab is designed with a flexible arched bending portion that can dynamically adjust its shape during battery operation. As the electrode expands during charging, the arched portion deforms to accommodate the volume change, preventing stress concentration and bonding breakage while maintaining the electrical connection
2Quantity of substance
If the electrode volume increases during charging, then the battery capacity is improved, but the electrode non-coating portion bends and breaks
Solution Approach 1:
The leadtab geometry is modified to include an arched bending portion with a specific curvature radius that is optimized to match the electrode expansion characteristics. This parameter optimization allows the leadtab to accommodate volume changes during charging cycles without causing breakage to the electrode non-coating portion
Solution Approach 2:
The arched bending portion is pre-formed with a curvature that provides built-in flexibility and stress absorption capacity. This pre-designed geometric feature acts as a cushion that absorbs the stress generated during electrode expansion before it can transmit to the bonding portion, preventing breakage while allowing full electrode capacity utilization
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
Prevents breakage of the electrode non-coating portion, thereby maintaining battery performance by minimizing capacity decrement and resistance increase due to electrode expansion.
Implementation Method 1
an elastic structure is deformed depending upon electrode expansion at the bonding portion that mutually bonds (or fuses) an electrode non-coating portion inside the battery cell and a leadtab extending to the outside of the battery cell
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
A leadtab assembly may include an electrode non-coating portion having a plurality of stacked electrodes collected inside a battery cell, a leadtab for forming an electrical path to the outside of the battery cell, and a bonding portion for mutually bonding the electrode non-coating portion and the leadtab, wherein a cutting prevention portion is elastically deformed by the force applied to the electrode non-coating portion as the electrode is expanded at the bonding point located between the bonding portion and the leadtab.