Battery Tab-to-Terminal Riveting Without Transfer Sheet

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Solution Overview

Problem

Conventional methods for connecting tabs to terminal posts in lithium-ion batteries, such as riveting, screwing, or ultrasonic welding, result in reduced energy density, potential cracking, and safety risks due to welding slag, affecting battery performance and consistency.

Innovation Solution

A rivet is used to connect the tab and terminal post without a transfer sheet, forming an integrally connected member, thereby improving energy density and safety by eliminating welding slag and tab cracking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If ultrasonic welding or laser welding is used to connect the tab and terminal post, then the connection strength is improved, but welding slag is generated causing safety risks and tab cracking occurs reducing yield rate

Engineering Contradiction:

Improveconnection strengthVSAvoidwelding slag and tab cracking

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the welding process (thermal/mechanical system) with a riveting process (mechanical fastening system). The rivet is inserted through the tab and terminal post and deformed to create a mechanical interlock, eliminating the need for welding and thus preventing welding slag generation and tab cracking associated with welding processes.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If a transfer sheet is used to connect the electrode assembly to the terminal post, then the connection reliability is improved, but the weight increases and energy density decreases

Engineering Contradiction:

Improveconnection reliabilityVSAvoidbattery weight

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The patent extracts and eliminates the transfer sheet from the battery structure. Instead of using a separate transfer sheet component to connect the electrode assembly to the terminal post, the rivet directly connects the tab (attached to the electrode assembly) to the terminal post, removing the redundant transfer sheet and reducing overall weight while maintaining connection reliability.

Inventive Principle:

Principle #2Taking out (Extraction)

3Ease of manufacture

If conventional welding methods are used to connect the tab and terminal post, then the connection is achieved, but production costs increase due to low yield rate from tab cracking

Engineering Contradiction:

Improvemanufacturing feasibilityVSAvoidyield rate

Core Design Contradiction:

Ease of manufactureVSProductivity

Solution Approach 1:

The patent replaces the welding process with a riveting process that is less prone to causing tab cracking. The mechanical deformation of the rivet creates a secure connection without the high heat and stress concentrations that cause cracking in welding, thereby improving yield rate and reducing production costs while maintaining manufacturing feasibility.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentEP4683100A1Secondary battery, battery pack and electronic device

Publication Date: 2026.01.21 AESC JAPAN LTD

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AI summary

A secondary battery (100), a battery pack (1002), and an electronic device (1000) is provided. The secondary battery (100) includes a top cover (172), a terminal post (50) disposed on the top cover (172), an electrode assembly (120), and a rivet (10). The electrode assembly (120) includes a cell body (124) and a tab (122) protruding from the cell body (124). A riveting hole (1220) is provided on the tab (122). The rivet (10) is connected to the terminal post (50) and penetrates through the riveting hole (1220) to rivet the terminal post (50) and the tab (122).