Battery Tab-to-Post Snap-Fit Connection for Weld-Free Assembly
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Solution Overview
Problem
The complex welding process between connecting sheets in batteries complicates assembly, reduces efficiency, and increases the risk of short circuits due to welding slag, affecting the performance and assembly efficiency of the battery.
Innovation Solution
The connection between the tab and post assembly is achieved through a snap-fit mechanism using a connecting sheet assembly with a first and second connecting sheet, where one sheet is snapped onto the other, eliminating the need for welding and reducing the risk of short circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a lithium ion battery uses a conventional diaphragm without liquid retention grooves, then the battery structure is simple, but liquid electrolyte leaks during swelling of the gel polymer electrolyte
Solution Approach 1:
The diaphragm is segmented into multiple functional zones: a liquid retention groove formed as a recess portion, a wick structure with capillary pores, and a base layer. This segmentation allows each zone to perform its specific function - the groove contains electrolyte, the wick transports it via capillary action, and the base provides structural support, thereby preventing electrolyte leakage while managing the swelling gel polymer electrolyte effectively.
Solution Approach 2:
The wick structure acts as an intermediary between the liquid retention groove and the gel polymer electrolyte. It uses capillary forces to automatically transport liquid electrolyte from the groove to the swelling gel polymer electrolyte, mediating the interaction between these components and ensuring continuous electrolyte supply without mechanical pumps or complex mechanisms.
2Reliability
If the diaphragm uses a wick structure with capillary pores, then liquid electrolyte is retained effectively, but the diaphragm manufacturing complexity increases
Solution Approach 1:
The wick structure is made from porous materials such as porous polyolefin or porous polyester, which naturally possess capillary pores for liquid transport. These materials can be manufactured using established processes like electrospinning, phase separation, or sintering, making the diaphragm fabrication feasible with existing manufacturing techniques while achieving effective liquid electrolyte retention through capillary action.
Solution Approach 2:
The diaphragm is constructed as a composite structure combining multiple materials: a porous wick material for capillary transport, a base material for structural support, and potentially coated layers for enhanced performance. This composite approach allows optimization of each layer's properties and enables manufacturing through layer-by-layer assembly or co-forming techniques.
3Quantity of substance
If the battery uses a gel polymer electrolyte that swells during charging, then battery capacity increases, but liquid electrolyte leaks from the battery
Solution Approach 1:
The liquid retention groove is pre-formed in the diaphragm structure before battery assembly, creating a reservoir that anticipates the electrolyte consumption during gel polymer electrolyte swelling. This preliminary preparation ensures that liquid electrolyte is already positioned and contained in the groove, ready to be supplied to the gel polymer electrolyte as it expands during charging, preventing leakage before it can occur.
Solution Approach 2:
The wick structure enables self-service liquid electrolyte transport through capillary action, automatically supplying electrolyte to the swelling gel polymer electrolyte without external intervention. The system self-regulates the electrolyte flow based on the gel polymer electrolyte's swelling state, maintaining proper lubrication and ionic conductivity while preventing overflow and leakage.
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
The snap-fit connection improves assembly efficiency, reduces the risk of short circuits, and enhances the reliability and performance of the battery by ensuring a stable and secure connection without the need for welding.
Implementation Method 1
a wick structure formed integrally with the diaphragm, the wick structure having a capillary force to function as a path for the liquid electrolyte to move toward the gel polymer electrolyte
Implementation Method 2
a gel polymer electrolyte layer formed integrally with the positive electrode and the negative electrode, the gel polymer electrolyte layer being swellable when a lithium ion battery in which the gel polymer electrolyte layer is used as an electrolyte is in a charged state
Data Source
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AI summary
A battery includes a cell, a post assembly and a connecting sheet assembly. The cell includes a tab. The post assembly is connected to the tab. The tab and the post assembly are connected by the connecting sheet assembly. The connecting sheet assembly includes a first connecting sheet and a second connecting sheet. One of the first connecting sheet and the second connecting sheet is connected to the tab, and the other is connected to the post assembly. The first connecting sheet is snapped with the second connecting sheet. The battery of this application can solve the problems that the connecting sheet on the tab and the connecting sheet on the post assembly are connected by welding process, and the welding process is relatively complicated and affects the assembling efficiency of the battery.