Battery Cell End Cap Welding Layout to Prevent Micro-Cracks

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Solution Overview

Problem

Existing battery technologies face issues with poor safety and performance due to micro-cracks at the welding interface between different metal materials, leading to electrolyte leakage and degradation over time.

Innovation Solution

A conductive piece is positioned close to the welding region between the end cap and the housing, allowing for molten welding using residual heat from the welding process, forming a conductive cross-section without external penetration welding, thus reducing energy consumption and preventing micro-cracks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If penetration welding is used to connect the end cap and conductive piece from outside, then electrical connection is achieved, but micro-cracks occur at the welding interface between different metal materials leading to electrolyte leakage

Engineering Contradiction:

Improvewelding interface integrityVSAvoidmicro-cracks and electrolyte leakage

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The conductive piece serves as an intermediary element positioned between the electrode assembly and end cap. By placing the conductive piece's outer edge close to the welding region (within 15mm), it enables indirect welding using residual heat from the end cap to housing welding process, avoiding direct penetration welding between dissimilar metals that causes micro-cracks

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the traditional mechanical penetration welding process with a thermal conduction-based welding approach. The residual heat from welding the end cap to the housing is conducted to the conductive piece, which then welds to the end cap or housing without requiring external penetration welding equipment or processes

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If additional welding step is performed to connect the conductive piece to the end cap, then electrical connection is ensured, but manufacturing process complexity increases

Engineering Contradiction:

Improveelectrical connection reliabilityVSAvoidmanufacturing process steps

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges two separate welding operations into one: the welding of the end cap to the housing and the welding of the conductive piece to the end cap or housing. By positioning the conductive piece near the welding region, the residual heat from the first welding operation simultaneously performs the second welding operation, eliminating the need for an additional welding step

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The end cap welding process serves multiple functions: it seals the housing opening, provides structural support, and simultaneously generates the residual heat needed to weld the conductive piece to either the end cap or housing. This multi-functionality reduces overall process complexity

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Reliability

If external penetration welding is used to weld the end cap and conductive piece, then connection is achieved, but energy consumption increases

Engineering Contradiction:

Improvewelding connection strengthVSAvoidwelding energy consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The welding process is made self-service by utilizing the residual heat generated during the end cap to housing welding operation. This residual heat automatically welds the conductive piece to either the end cap or housing without requiring additional external energy input or separate welding operations

Inventive Principle:

Principle #25Self-service

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 method enhances electrical conductivity and safety by eliminating micro-cracks, preventing electrolyte leakage, and simplifying the manufacturing process.

Implementation Method 1

the conductive piece being molten-welded to the at least one of the end cap and the housing by using the heat from welding

Methodology Applied

Scientific EffectWelding: Welding

Implementation Method 2

residual heat during welding of the end cap and the housing is indirectly used for molten welding of the conductive piece

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

high temperatures make the atoms of a top metal layer dissolve in each other to form a conductive cross section

Methodology Applied

Scientific EffectAtomic diffusion: Diffusion

Data Source

PatentUS20260031501A1Battery cell, method for manufacture same, battery, and power consuming device

Publication Date: 2026.01.29 CONTEMPORARY AMPEREX TECHNOLOGY (HONG KONG) LIMITED

AI summary

A battery cell includes: a housing, an opening being provided at an end portion of the housing; an electrode assembly arranged inside the housing, the electrode assembly including an electrode body and a first tab; an end cap closing the opening; and a conductive piece located between the electrode assembly and the end cap, and electrically connected to the first tab, wherein the end cap is in direct contact with an inner surface of the housing, the conductive piece is in direct contact with the inner surface of the housing along a first direction, and the conductive piece is in direct contact with the end cap along a second direction, the first direction being approximately perpendicular to the second direction.