Cylindrical Cell Cover Assembly to Eliminate Dead Volume

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Solution Overview

Problem

Existing lithium-ion energy storage elements, particularly cylindrical round cells, face challenges in achieving high energy density while maintaining the ability to handle high currents and ensuring safety, with dead volumes in their construction negatively impacting energy density and safety features.

Innovation Solution

The design incorporates an airtight and liquid-tight housing with a metallic cup-shaped housing part and a cover component that includes a connection pole electrically insulated from the cover plate, allowing for compact construction and efficient electrical contact of both anode and cathode via the cover component, with integrated safety features like a metallic membrane and grooves for pressure equalization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If traditional cylindrical round cell construction is used, then the cell can provide high currents, but dead volumes reduce energy density

Engineering Contradiction:
Improveenergy densityVSAvoiddead volumes
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent merges the cover component with the connection pole structure, eliminating the need for separate connection components and reducing dead volumes. The cover plate is integrated with the connection pole to form a unified structure that contacts both electrodes, thereby maximizing space utilization and improving energy density while maintaining high current capability.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If safety features like pressure equalization are integrated, then safety is improved, but device complexity increases

Engineering Contradiction:
ImprovesafetyVSAvoidstructural complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The pressure equalization feature is integrated into the housing base structure through grooves and a metallic membrane, combining safety functionality with the existing structural components. This approach improves safety by enabling pressure relief while avoiding the addition of separate safety mechanisms that would increase device complexity.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If connection pole is electrically insulated from cover plate, then electrical contact efficiency is improved, but manufacturing complexity increases

Engineering Contradiction:
Improveelectrical contact efficiencyVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent uses a casting compound as an intermediary material that provides electrical insulation between the cover plate and connection pole while maintaining mechanical integration. This casting compound fills the space between these components, ensuring proper electrical isolation without requiring complex insulating structures, thereby achieving efficient electrical contact while keeping manufacturing relatively simple.

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 design enhances energy density by eliminating dead volumes and improves safety through efficient electrical contact and integrated pressure equalization, enabling the cells to handle high currents and pressures effectively.

Implementation Method 1

The housing base has integrated safety features for pressure equalization in the event of overpressure

Methodology Applied
Scientific EffectPressure equalization: Pressure Gradient

Implementation Method 2

The housing base has integrated safety features for pressure equalization in the event of overpressure, including a metallic membrane and grooves

Methodology Applied
Scientific EffectElastic deformation: Deformation

Implementation Method 3

a connection pole (102b), which is guided through an opening (102d) in the cover plate (102a) and is electrically insulated from the cover plate (102a), the contact plate (111) being electrically connected to the connection pole (102b)

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 4

Electrochemical energy storage elements are able to convert stored chemical energy into electrical energy through a redox reaction

Methodology Applied
Scientific EffectRedox reaction: Redox Reactions

Implementation Method 5

The separator thus prevents direct contact between the electrodes. At the same time, however, it enables electrical charge equalization between the electrodes

Methodology Applied
Scientific EffectPhysical separation: Physical Containment

Implementation Method 6

This ion current passes through the separator and is made possible by an ion-conducting electrolyte

Methodology Applied
Scientific EffectIon conduction: Conduction (electrical)

Data Source

PatentEP4266438A1Energy storage element and method for the production of same
Publication Date: 2023.10.25 VARTA MICROBATTERY GMBH
  • EP4266438A1 patent drawingFigure 1A~1D
  • EP4266438A1 patent drawingFigure 2A~2C
  • EP4266438A1 patent drawingFigure 3A~3B

AI summary

An energy storage element (100) comprises an airtight and liquid-tight housing and an electrode-separator assembly (104) arranged therein, which includes an anode current collector (106) loaded with a layer of negative electrode material (107) and a cathode current collector (109) loaded with a layer of positive electrode material (110). The housing comprises a metallic, cup-shaped housing part (101) having a housing base (101a), a circumferential side wall and an end opening, as well as a lid component (102) that closes the end opening of the cup-shaped housing part (101). An edge (106a, 109a) of the anode current collector (106) or of the cathode current collector (109) is electrically connected to the housing base (101a) and another edge (106a, 109a) to a contact plate (111) that sits directly on this edge.The cover component (102) comprises a metallic cover plate (102a) and a terminal (102b) which passes through an opening in the cover plate (102a) and is electrically insulated from the cover plate (102). The terminal (102b) sits directly on the contact plate (111) and is welded to it. Furthermore, the terminal (102b) is electrically insulated from the cover plate (102) by a hardened potting compound (113) made of an electrically insulating plastic material. The cover component (102) can be manufactured during housing assembly.