Cylindrical Battery Cell Terminal Layout to Prevent Cover Plate Leakage

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Solution Overview

Problem

Existing battery cells face safety issues due to the vulnerability of the joint between the cover plate and the case, which can lead to electrolyte leakage and potential hazards when subjected to external impact.

Innovation Solution

The electrode terminal is mounted to the case away from the cover plate, increasing the distance between the joint and reducing the effect of external impact, while the cover plate is welded or sealed to enhance airtightness and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of moving object

If a battery cell is repeatedly charged and discharged, then the battery capacity increases initially, but the battery reaches a saturation state where capacity cannot be further improved and may degrade

Engineering Contradiction:
Improvebattery capacityVSAvoidbattery stability
Core Design Contradiction:
Duration of action of moving objectVSReliability

Solution Approach 1:

The patent applies preliminary action by performing a specific formation process before the battery reaches saturation. The formation process includes charging to 4.4V or higher and holding for 10 hours or more, which pre-treats the lithium ion crystal structure in advance. This preliminary treatment creates a stable crystal structure that prevents future degradation, allowing the battery to maintain high capacity without reaching the harmful saturation state.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent applies parameter changes by modifying the formation process parameters: charging voltage increased to 4.4V or higher (above conventional levels), holding time extended to 10 hours or more, and temperature controlled at 45°C or higher. These parameter changes transform the lithium ion crystal structure to a more stable configuration, enabling the battery to achieve and maintain high capacity without degradation.

Inventive Principle:
Principle #35Parameter changes

2Quantity of substance

If the battery is overcharged to increase capacity, then more lithium ions are inserted into the crystal structure, but lithium ions become disordered and capacity degrades

Engineering Contradiction:
Improvelithium ion insertion amountVSAvoidlithium ion crystal structure order
Core Design Contradiction:
Quantity of substanceVSStability of the object's composition

Solution Approach 1:

The patent applies preliminary action by performing an extended holding step (10 hours or more) at high voltage (4.4V or higher) before normal operation. This preliminary treatment allows lithium ions to be inserted in a controlled manner and properly organized into the crystal structure, preventing disorder that would occur with rapid overcharging. The slow, controlled insertion during formation creates a stable foundation for future high-capacity operation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent applies continuity of useful action by maintaining the high voltage state (4.4V or higher) for an extended period (10 hours or more) during formation. This continuous treatment ensures that lithium ions have sufficient time to properly integrate into the crystal structure in an ordered arrangement, rather than being forced in rapidly which would cause disorder. The continuous holding action transforms the structure gradually and safely.

Inventive Principle:
Principle #20Continuity of useful action

3Speed

If the battery is charged quickly to reduce time, then charging speed increases, but the battery reaches saturation faster and capacity degrades

Engineering Contradiction:
Improvecharging speedVSAvoidbattery lifespan
Core Design Contradiction:
SpeedVSDuration of action of moving object

Solution Approach 1:

The patent applies preliminary action by performing a slow, extended formation charge (10 hours or more at 4.4V or higher) before normal use. This preliminary slow charging properly organizes the lithium ion crystal structure in advance, creating a robust foundation that can later withstand faster charging rates without degrading. The preliminary treatment prepares the battery for high-speed operation while protecting against saturation-induced degradation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent applies beforehand cushioning by using an extended holding period at high voltage during formation to cushion against future charging stresses. This preliminary treatment creates a buffer in the crystal structure that absorbs the shock of rapid charging, preventing the lithium ions from becoming disordered even when fast charging is subsequently applied. The cushioning effect allows fast charging without degradation.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 configuration reduces the risk of connection failure and electrolyte leakage, enhancing safety and airtightness, and simplifies assembly by allowing both terminals to be located at the same end for easier grouping.

Implementation Method 1

a positive electrode, a negative electrode, and an electrolyte, in which a lithium ion battery is constructed by inserting a lithium ion positive electrode into a lithium ion negative electrode

Methodology Applied
Scientific EffectElectrochemical reaction: Battery (electricity)

Data Source

PatentEP4293769B1Battery cell, battery, and electrical apparatus
Publication Date: 2026.04.29 CONTEMPORARY AMPEREX TECHNOLOGY (HONG KONG) LIMITED
  • EP4293769B1 patent drawingFigure 1
  • EP4293769B1 patent drawingFigure 2
  • EP4293769B1 patent drawingFigure 3

AI summary

Provided in the embodiments of the present application are a battery cell, a battery, and an electric device. The battery cell comprises a housing, an electrode assembly, a first electrode terminal and a cover plate. The housing comprises a cylindrical body and a cover body, which are integrally formed, and one end of the cylindrical body away from the cover body is provided with an opening. The electrode assembly is accommodated inside the housing and comprises a first tab. The first electrode terminal is arranged on the cover body and is used for being electrically connected to the first tab. The cover plate is connected to the cylindrical body and covers the opening. By means of mounting the first electrode terminal on the cover body, the space between the position, where the cylindrical body and the cover plate are connected to each other, and the first electrode terminal can be increased, such that effect on the position, where the cylindrical body and the cover plate are connected to each other, is reduced when the battery cell is subjected to an external impact, the risk of connection failure between the cover plate and the housing is reduced, and electrolyte leakage is reduced, thereby improving the safety.