Cylindrical Battery Tab Structure for Faster Electrolyte Wetting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The low wetting efficiency of electrolyte in cylindrical batteries due to blocking by current-collecting members and tabs during the manufacturing process, which limits production efficiency and battery performance.
Innovation Solution
A secondary battery design with a first cut segment forming a first annular region and a projection of a second filling hole covering a third annular region, allowing direct absorption and radial penetration of electrolyte, while minimizing interference from tabs and current-collecting members.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If current-collecting members and tabs are used to connect electrode sheets, then electrical connection is achieved, but electrolyte wetting efficiency is reduced due to blocking
Solution Approach 1:
The current-collecting member is divided into multiple segments: a first current-collecting member with a first filling hole, a second current-collecting member with a second filling hole, and transition connection portions. This segmentation allows electrolyte to penetrate through the filling holes while maintaining electrical connection, resolving the contradiction between electrical connectivity and electrolyte wetting efficiency
Solution Approach 2:
The filling holes act as intermediaries that allow electrolyte to pass through the current-collecting members. By introducing these holes, the current-collecting members no longer completely block electrolyte flow, enabling both electrical connection and effective electrolyte distribution to the electrode assembly
2Reliability
If tabs are bent to form current connections, then electrical connectivity is established, but electrolyte flow paths are blocked
Solution Approach 1:
The uncoated foil region is segmented into a first cut segment and an uncut segment. The uncut segment is bent to form the tab for electrical connection, while the first cut segment forms an annular region with a filling hole that allows electrolyte to flow through, preventing complete blockage of electrolyte paths
Solution Approach 2:
The filling hole introduces a new dimension (axial penetration) for electrolyte flow, allowing electrolyte to pass through the current-collecting member from one end to the other, rather than being blocked by the tab structure in the radial direction
3Reliability
If current-collecting members are placed to connect tabs, then electrical connection is achieved, but electrolyte injection and distribution are hindered
Solution Approach 1:
The filling holes are pre-formed in the current-collecting members before assembly. This preliminary action ensures that electrolyte injection paths are already established, making the subsequent electrolyte injection process easier and more effective without being hindered by the current-collecting members
Solution Approach 2:
The filling holes serve as intermediaries that facilitate electrolyte injection through the current-collecting members. By introducing these holes, the current-collecting members transform from obstacles to facilitators of electrolyte distribution
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
Improves electrolyte wetting efficiency, enhances uniformity of electrolyte distribution, and increases battery performance and service life by ensuring unobstructed electrolyte flow and reduced risk of miswelds.
Implementation Method 1
The uncut segment of the uncoated foil region is bent to form a tab
Implementation Method 2
In a radial direction of the electrode assembly, the first cut segment is wound to form a first annular region
Implementation Method 3
The current-collecting member is arranged between the electrode assembly and the end wall, connected to the tab by welding
Data Source
AI summary
A secondary battery, a battery module, and an electronic apparatus are provided. The secondary battery includes a casing, an electrode assembly, and a current-collecting member. The casing includes an end wall provided with a first filling hole. The electrode assembly accommodated in the casing includes a first electrode sheet, a second electrode sheet, and a separator stacked and wound to form a wound structure. An end portion of the first electrode sheet includes an uncoated foil region extending from the separator in an axial direction of the electrode assembly and including a first cut segment and an uncut segment, and the uncut segment is bent to form a tab. The current-collecting member connected to the tab includes a second filling hole.