Cylindrical Battery Electrode Assembly for Faster Electrolyte Wetting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The manufacturing process of cylindrical batteries is hindered by low electrolyte wetting efficiency due to blocking by current-collecting members and tabs, affecting production efficiency and battery performance.
Innovation Solution
A secondary battery design with a first cut segment forming an annular region and a tab-free third annular region exposed within a filling hole, allowing direct electrolyte absorption and penetration, combined with a current-collecting member projection covering the third annular region to prevent blocking and miswelds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If tabs are arranged at both ends of the electrode assembly and electrically connected to current-collecting members, then electrical connection is achieved, but the current-collecting members and tabs block electrolyte injection and electrode assembly wetting
Solution Approach 1:
The uncoated foil region is divided into three segments: a first cut segment forming an annular region, a second cut segment forming another annular region, and an uncut segment forming a tab. This segmentation allows different regions to serve different functions - the cut segments create electrolyte access paths while the uncut segment provides electrical connection.
Solution Approach 2:
Different regions of the uncoated foil are given different properties: the first and second cut segments create open annular regions for electrolyte penetration, while the uncut segment maintains continuity for tab formation. The current-collecting member is designed with a filling hole that aligns with specific annular regions to optimize electrolyte flow while maintaining electrical connection.
2Productivity
If the electrode assembly uses a wound structure with tabs at both ends, then the structure is compact and efficient, but the production efficiency is limited due to low electrolyte wetting efficiency
Solution Approach 1:
The uncoated foil region is pre-cut in specific patterns before winding to create annular regions that will facilitate electrolyte penetration. The first and second cut segments are removed in advance, creating predetermined pathways for electrolyte flow that become active after the electrode assembly is wound and assembled.
3Manufacturing precision
If the third annular region is exposed outside the second annular region without being blocked by the tab, then electrolyte can flow directly into the third annular region, but the current-collecting member may block the region
Solution Approach 1:
The current-collecting member is positioned within the electrode assembly structure, with its filling hole aligned to expose the third annular region. The projection of the filling hole covers the third annular region, creating a nested arrangement where the filling hole provides access to the annular region while being integrated within the overall battery structure.
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
Enhances electrolyte wetting efficiency and uniformity, reduces the risk of miswelds, and improves battery performance and service life by ensuring unobstructed electrolyte flow and absorption.
Implementation Method 1
the electrolyte directly flows into the third annular region exposed within the second filling hole. The electrolyte is directly absorbed by the separator of the third annular region and penetrates radially to wet the electrode assembly during the flowing process
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A secondary battery (100), a battery pack (10), and an electronic device (1) are provided. The secondary battery (100) includes a casing (110), an electrode assembly (120), and a current-collecting member (140). The casing (110) includes an end wall (111) provided with a first filling hole (115). The electrode assembly (120) accommodated in the casing (110) includes a first electrode sheet (123), a second electrode sheet (121), and a separator (122) stacked and wound to form a wound structure (126). An end portion of the first electrode sheet (123) includes an uncoated foil region (1233) extending from the separator (122) in an axial direction of the electrode assembly (120) and including a first cut segment (12331) and an uncut segment (12332), and the uncut segment (12332) is bent to form a tab (124). The current-collecting member (140) connected to the tab (124) includes a second filling hole (143).