Energy Storage Module Sealing With Low-Conductivity Restraints

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Solution Overview

Problem

The existing methods for producing storage modules with layered electrode sheets face issues with sealability due to heat conductivity of metal restraining members, which conducts heat away from the seal surface, leading to insufficient sealing.

Innovation Solution

A method involving a low heat conductivity restraining member, made of materials like inorganic materials or resins, is used to apply pressure and heat to the frame body, forming a seal while preventing heat conduction to the restraining member, thereby enhancing sealability and durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If metal restraining members are used to apply pressure to minimize layered body thickness, then volume energy density is improved, but heat conductivity increases causing insufficient sealability

Engineering Contradiction:
Improvevolume energy densityVSAvoidsealability
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent changes the material parameter of the restraining member from metal (high heat conductivity) to materials with low heat conductivity (1 W/m·K or less), such as ceramic or composite materials. This parameter change allows the restraining member to maintain its pressure-applying function while preventing heat conduction that would compromise sealability during the heating process.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies different material properties to different parts of the system: the restraining member is specifically designed with low heat conductivity material to perform its localized function of applying pressure without conducting heat away from the sealing area, while other components may use different materials optimized for their specific functions.

Inventive Principle:
Principle #3Local quality

2Reliability

If heating is applied to weld frame bodies for sealing, then sealability is improved, but heat conduction to restraining member causes heat loss and insufficient welding temperature

Engineering Contradiction:
ImprovesealabilityVSAvoidheat loss
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The restraining member acts as a thermal intermediary with low heat conductivity, positioned between the heating source and the layered body. This intermediary prevents excessive heat conduction to the restraining member itself, maintaining sufficient heating temperature at the frame body sealing surfaces while still allowing the restraining member to apply necessary pressure during the welding process.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 approach results in a storage module with improved sealability and durability by ensuring heat is retained to effectively weld the frame bodies, creating a robust seal.

Implementation Method 1

in the heating step, the seal part in the layered body and the pair of restraining member are heated by a radiation superheater

Methodology Applied
Scientific EffectThermal radiation: Thermal Radiation

Implementation Method 2

when the side surface of the layered body is heated, a part of the heat applied to the side surface of the layered body is conducted to the restraining member side

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

heating the frame body in the layered body and the pair of restraining member while applying a restraining pressure to the layered body by the pair of restraining member, and thereby welding the frame body adjacent to each other in the first direction to form a seal part

Methodology Applied
Scientific EffectWelding: Welding

Data Source

PatentEP4418389A1Method for producing energy storage module and energy storage module
Publication Date: 2024.08.21 TOYOTA JIDOSHA KK
  • EP4418389A1 patent drawingFigure 1
  • EP4418389A1 patent drawingFigure 2
  • EP4418389A1 patent drawingFigure 3~4B

AI summary

A main object of the present disclosure is to provide a method for producing a storage module with excellent sealability. The present disclosure achieves the object by providing the method including: a preparing step of preparing a layered body, in which a plurality of electrode sheet that includes : an electrode including a current collector and an active material layer; and a frame body made of a resin arranged along an outer periphery of the electrode, is layered in a first direction; an arranging step of arranging a pair of restraining member of which heat conductivity is 1 W/m·K or less, in a position overlapping with the frame body in the layered body when viewed from the first direction; and a heating step of heating the frame body in the layered body and the pair of restraining member while applying a restraining pressure to the layered body by the pair of restraining member, and thereby welding the frame body adjacent to each other in the first direction to form a seal part.