Battery Cell Double Welding Structure for Tab Length Reduction
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Solution Overview
Problem
Conventional battery cell designs face challenges in increasing energy density due to long electrode tabs, which lead to reduced active material area and potential disconnection risks when shortened, compromising safety and stability.
Innovation Solution
A battery cell design featuring electrode groups with conductive connecting members having circular arc bent sections, forming first and second welding junctions to securely connect electrode tabs to leads, minimizing tab length while maintaining a stable connection and increasing active material area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the electrode tabs are lengthened to ensure proper connection to electrode leads, then the connection reliability is improved, but the area coated with electrode active material decreases, reducing battery capacity
Solution Approach 1:
The electrode tab connection structure is segmented into multiple components: electrode tabs, conductive connecting members, and electrode leads. The conductive connecting members act as intermediate segments that bridge the electrode tabs and leads, allowing the electrode tabs to be shorter while maintaining connection reliability through the distributed connection structure.
Solution Approach 2:
Conductive connecting members serve as intermediary elements between the electrode tabs and electrode leads. These intermediaries transfer electrical connection functionality from the tabs to the leads, enabling shorter tabs without compromising connection reliability. The conductive connecting members mediate the connection task, decoupling the tab length from the connection distance requirement.
2Quantity of substance
If the electrode tabs are shortened to increase the area coated with active material, then the battery capacity is improved, but the bonding force of the electrode tab junction weakens, increasing disconnection risk
Solution Approach 1:
The connection system is segmented so that the electrode tabs do not need to span the entire distance to the leads. Instead, the conductive connecting members are segmented elements that provide multiple bonding interfaces, distributing the mechanical stress and maintaining bonding strength even with shorter tabs.
Solution Approach 2:
The conductive connecting members act as intermediary elements that bear and distribute the mechanical bonding load. They mediate between the short electrode tabs and the electrode leads, providing sufficient bonding force through their own structural design and multiple connection points, thus compensating for the reduced tab length and bonding area.
3Quantity of substance
If the number of stacked electrodes is increased to enhance energy density, then the battery capacity is improved, but the length of electrode tabs required for connection increases, reducing the active material area
Solution Approach 1:
Conductive connecting members serve as intermediary elements that decouple the relationship between electrode stack height and tab length. They provide a flexible connection path that can accommodate increased electrode stacking without requiring proportionally longer tabs, as the connecting members bridge the increased distance independently of tab length.
Solution Approach 2:
The connection structure transitions from a planar tab-extension approach to a three-dimensional arrangement using conductive connecting members. These members can be positioned and routed in multiple dimensions, allowing connection across increased electrode stacking heights without extending tab length in the plane of the electrodes, thus preserving active material area.
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 design enhances energy density by shortening electrode tabs, reduces stress on connections, and ensures a stable and safe coupling between electrode tabs and leads, thereby improving battery performance and safety.
Implementation Method 1
a first welding junction formed between one end of the conductive connecting member and the electrode tab junction and a second welding junction formed between the other end of the conductive connecting member and the electrode lead
Data Source
Figure 1~2
Figure 2b~3a
Figure 3b~4
AI summary
The present disclosure provides a battery cell including: two or more electrode groups having a structure in which electrodes including a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode are stacked, wherein each of the electrode groups includes an electrode tab junction on one side and is electrically connected to an electrode lead drawn to an outside of a battery case via a conductive connecting member, and has a structure including a first welding junction formed between one end of the conductive connecting member and the electrode tab junction and a second welding junction formed between the other end of the conductive connecting member and the electrode lead.