Battery Cell Current Collector Without Welding for Short-Circuit Risk
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Solution Overview
Problem
Welding of current collecting members in battery cells leads to the production of metal particles that can cause short circuits, posing safety risks.
Innovation Solution
A battery cell design where the current collecting member is partially located between the electrode assembly and the end cover, abutting against it without welding, featuring a first hole to accommodate part of the electrode assembly and increase electrical contact area, and optionally incorporating a depression portion and protrusions to enhance fitting and current flow capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional injection molding machine is used for battery cell production, then device complexity is reduced, but manufacturing precision deteriorates due to inability to control resin flow and prevent bubbles
Solution Approach 1:
The injection molding system is segmented into multiple independent injection units (first injection unit for resin, second injection unit for lubricant) that can be controlled separately. This allows precise control of resin flow and lubricant application, preventing bubbles and ensuring uniform density while maintaining manageable system complexity through modular architecture
Solution Approach 2:
A lubricant is introduced as an intermediary substance between the resin and the mold cavity wall. This lubricant layer prevents resin from adhering to the mold, eliminates bubbles caused by resin-mold adhesion, and ensures smooth resin flow. The lubricant is applied through a dedicated second injection unit that operates independently from the resin injection system
2Productivity
If production speed is increased to meet demand, then productivity improves, but manufacturing precision deteriorates due to inability to control resin flow evenly
Solution Approach 1:
The lubricant is injected in advance into the mold cavity before the resin is injected. This preliminary action creates a lubricant layer on the mold wall that prepares the surface for resin flow, preventing adhesion and bubbles from the outset. This allows high-speed production cycles while maintaining consistent resin flow uniformity and preventing defects
Solution Approach 2:
The system incorporates sensors and control mechanisms that monitor resin flow and injection parameters in real-time. Based on this feedback, the injection units adjust their operation to maintain optimal flow rates and pressure, ensuring uniform resin distribution even at high production speeds. The lubricant injection timing and amount are also adjusted based on feedback from previous cycles
3Productivity
If resin is injected at high speed to increase productivity, then production volume increases, but manufacturing precision deteriorates due to bubble formation and adhesion
Solution Approach 1:
The lubricant serves as a mediator between the high-speed resin injection and the mold cavity. By creating a lubricant layer on the mold wall before resin injection, it prevents resin adhesion and bubble formation even at high injection rates. This intermediary layer allows the system to operate at high productivity while maintaining manufacturing precision and preventing defects
Solution Approach 2:
The lubricant injection occurs as a preliminary action before the high-speed resin injection. This timing ensures that the mold cavity is properly prepared with a lubricant coating that can handle the high-velocity resin flow, preventing adhesion and bubbles that would otherwise occur at high injection speeds
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
Reduces the risk of short circuits by minimizing metal particles and improves current flow capacity through enhanced electrical contact, thereby increasing the battery's efficiency and energy density.
Implementation Method 1
an injection unit that injects lubricant into the mold cavity in the state where the mold is closed
Implementation Method 2
a resin injection unit that injects resin into the mold cavity
Data Source
Figure 1~2
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AI summary
This application discloses a battery cell, a manufacturing method and manufacturing system of same, a battery, and an electric device. The battery cell of the embodiments of this application includes an electrode assembly; a housing configured to accommodate the electrode assembly and having an opening; an end cover configured to close the opening of the housing; and a current collecting member configured to electrically connect the electrode assembly to the end cover, where the current collecting member is at least partly located between the electrode assembly and the end cover and abuts against the electrode assembly; the current collecting member has a first hole, where the first hole is configured to accommodate part of the electrode assembly and make the electrode assembly contact a hole wall of the first hole. As the current collecting member abuts against the electrode assembly and is thus connected to the electrode assembly without welding, fewer metal particles are left in the battery cell, thereby decreasing risks of short circuit. As the electrode assembly partly extends into the first hole and contacts the hole wall of the first hole, a contact area between the current collecting member and the electrode assembly can be increased, thereby increasing the current flow capacity.