Battery Cell Lid Sealing Around Electrode Tab Penetration

Solution Overview

Problem

Existing battery cell designs face challenges in improving sealing properties due to moisture and gas permeation through lid members and exterior films, which affect the stability and performance of the battery cell.

Innovation Solution

The battery cell design incorporates a bonding member between the tab and the lid member, a barrier member on the lid member, and a rib structure on the lid member to enhance sealing, while also allowing for a thinner lid member with maintained strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a tab is drawn through a hole or notch in the lid member, then electrical connection is achieved, but moisture and gas can pass through the gap between the tab and lid member

Engineering Contradiction:

Improvesealing propertyVSAvoidmoisture and gas permeation

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A bonding member is introduced as an intermediary substance between the tab and the lid member. This bonding member fills the gap that would otherwise allow moisture and gas to penetrate, while still permitting the tab to pass through the lid member for electrical connection. The bonding member thus mediates between the conflicting requirements of electrical connectivity and sealing integrity.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The lid member is designed with different properties in different regions: the main body uses a resin with relatively high moisture and gas permeability for ease of manufacture and cost, while the region around the hole or notch uses a resin with low moisture and gas permeability to prevent penetration at the critical sealing location where the tab passes through.

Inventive Principle:

Principle #3Local quality

2Ease of manufacture

If a lid member with relatively high moisture and gas permeability is used, then ease of manufacture is improved, but moisture and gas permeation increases

Engineering Contradiction:

ImprovemanufacturabilityVSAvoidsealing property

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The lid member employs a multi-region resin composition strategy. The majority of the lid member uses a resin with relatively high moisture and gas permeability that is easy to manufacture, while the specific region surrounding the hole or notch uses a resin with low moisture and gas permeability to ensure sealing performance at the critical area where the tab penetrates.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The lid member is constructed as a composite structure combining different resin materials with contrasting permeability characteristics. This composite approach allows the lid member to simultaneously achieve ease of manufacture (through the use of readily processable resins in most areas) and effective sealing (through the use of low-permeability resin at the critical sealing region).

Inventive Principle:

Principle #40Composite materials

3Productivity

If the thickness of the lid member is decreased to improve volume energy density, then energy density is improved, but strength of the lid member is compromised

Engineering Contradiction:

Improvevolume energy densityVSAvoidlid member strength

Core Design Contradiction:

ProductivityVSStrength

Solution Approach 1:

The lid member is constructed as a composite structure combining different resin materials with contrasting permeability characteristics. This composite approach allows the lid member to simultaneously achieve ease of manufacture (through the use of readily processable resins in most areas) and effective sealing (through the use of low-permeability resin at the critical sealing region).

Inventive Principle:

Principle #40Composite materials

Data Source

PatentUS20240030523A1Battery cell

Publication Date: 2024.01.25 AESC JAPAN LTD

AI summary

A battery cell includes a battery element, a positive electrode tab electrically connected to the battery element, a front lid member covering one end of the battery element with the positive electrode tab drawn from the front lid member, and a front bonding member bonding the front lid member and the positive electrode tab to each other.