Battery Sealing Rivet Welding With Wider Laser Molten Pool

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing continuous laser welding methods for sealing rivets in batteries require precise fitting clearances, which are difficult to achieve and affect welding quality and reliability.

Innovation Solution

A novel welding method that expands the molten pool width by rotating or reciprocating the laser speckle along a secondary trajectory line, forming a wider and more uniform welding mark, allowing for improved fitting clearance and enhanced welding strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If continuous laser welding is used to weld sealing rivet to electrode post, then welding strength is improved, but fitting clearance requirements become too strict

Engineering Contradiction:
Improvewelding strengthVSAvoidfitting clearance
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The patent applies dynamic welding trajectory control where the laser beam performs rotational or reciprocating motion along a secondary trajectory line while moving along the primary welding path. This dynamic motion expands the molten pool width from a narrow continuous line to a wider distributed pattern, thereby reducing the sensitivity to fitting clearance requirements while maintaining welding strength

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent transitions from a one-dimensional continuous linear welding path to a two-dimensional welding pattern by introducing rotational or reciprocating motion in the transverse direction. The laser speckle rotates or reciprocates along a secondary trajectory line, creating a widened molten pool that covers a broader area, thus compensating for larger fitting clearances

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 method reduces the need for precise fitting clearances, improves welding reliability, and enhances the sealing performance of the battery by forming a wider and more uniform molten pool, thus ensuring better adhesion and safety.

Implementation Method 1

Laser welding is a secure and commonly used assembly method for sealing rivets

Methodology Applied
Scientific EffectLaser heating: Laser

Implementation Method 2

the molten pool formed by the existing continuous laser welding

Methodology Applied
Scientific EffectMelting: Melting

Data Source

PatentEP4708473A1Secondary battery, battery pack and electronic apparatus
Publication Date: 2026.03.11 AESC JAPAN LTD
  • EP4708473A1 patent drawingFigure 1
  • EP4708473A1 patent drawingFigure 2
  • EP4708473A1 patent drawingFigure 3

AI summary

A secondary battery (1), battery pack (8), and an electronic apparatus (9) are provided. The secondary battery (1) includes an electrode assembly (20), a casing (101), an electrode post (40), a sealing rivet (411), and a welding mark (60). The electrode assembly (20) is accommodated in the casing (101), and one end of the casing (101) has an opening portion (107). An end portion (407) of the electrode post (40) away from the electrode assembly (20) protrudes from the casing (101) through the opening portion (107), and the end portion (407) of the electrode post (40) is provided with a groove (409). The sealing rivet (411) is matched and embedded in the groove (409). The sealing rivet (411) is welded and fixed to the electrode post (40) through the welding mark (60) located on a connection portion of the sealing rivet (411) and the end portion (407).