Curved Battery Cell Design for Space Utilization

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing battery designs face challenges in maximizing space utilization and preventing short circuits when curved to fit ergonomic electronic devices, as they often suffer from stress-induced deformation and uneven electrode plate pushing, leading to shape issues and potential short circuits.

Innovation Solution

A battery cell with a changeable pouch-shaped case and a stack/folding type electrode assembly, where the electrode assembly is gently curved with a larger radius of curvature at the ends and a smaller radius at the middle, using a laminate sheet with a metal and resin layer for durability and thermal weldability, and an electrolyte that acts as a plasticizer to minimize stress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If the electrode assembly is directly thermally pressed to curve it, then the battery can be curved to fit electronic devices, but the battery deteriorates and shape deformation occurs

Engineering Contradiction:
Improvecurved shapeVSAvoidbattery deterioration
Core Design Contradiction:
ShapeVSReliability

Solution Approach 1:

The electrode assembly is curved during the assembly process before the electrolyte is injected, rather than curving it after assembly. This preliminary curving action prevents the electrolyte from causing stress restoration that would lead to shape deformation and short circuits.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

A curved support structure is used as an intermediary tool to curve the electrode assembly uniformly during assembly. This support structure provides even distribution of curving force, preventing localized stress concentration and shape deformation while achieving the desired curved shape.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Shape

If the electrode assembly is curved using heating rolls, then the battery can be curved, but some electrode plates are nonuniformly pushed and short circuits may occur

Engineering Contradiction:
Improvecurved shapeVSAvoidshort circuit risk
Core Design Contradiction:
ShapeVSObject-affected harmful factors

Solution Approach 1:

A curved support structure serves as an intermediary that provides uniform support during the curving process. This intermediary distributes the curving force evenly across all electrode plates, preventing nonuniform pushing that could cause short circuits while achieving the desired curved shape.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The curving process is performed at controlled temperature and pressure parameters during assembly, rather than using high-temperature heating rolls. This parameter control prevents thermal damage and nonuniform electrode plate deformation that could lead to short circuits.

Inventive Principle:
Principle #35Parameter changes

3Shape

If the battery is curved after electrolyte injection, then the electrode assembly can be curved, but stress restoration causes ends to be pressed and short circuit possibility increases

Engineering Contradiction:
Improvecurved shapeVSAvoidshort circuit risk
Core Design Contradiction:
ShapeVSObject-affected harmful factors

Solution Approach 1:

The electrode assembly is curved during assembly before the electrolyte is injected, rather than curving it after assembly. This preliminary curving action prevents the electrolyte from causing stress restoration that would lead to shape deformation and short circuits.

Inventive Principle:
Principle #10Preliminary action

4Ease of manufacture

If flat batteries are used in curved device regions, then manufacturing is simple, but space utilization is low and batteries may move freely causing damage

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidbattery stability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The battery is curved to match the curvature of the device's battery mounting region, creating a conformal fit. This equipotential curvature ensures the battery remains stable and secure in the curved region, preventing free movement and damage while maximizing space utilization.

Inventive Principle:
Principle #12Equipotentiality

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 configuration allows for efficient space utilization in curved devices, reduces the likelihood of short circuits by distributing stress evenly, and maintains the battery's curved shape during charge/discharge cycles, ensuring stable performance and design flexibility.

Implementation Method 1

when an electrolyte is injected in to the battery case in a state in which the curved electrode assembly is mounted in the battery case, stress immanent in the electrode assembly during curving the electrode assembly is restored by a plasticizing action of the electrolyte

Methodology Applied
Scientific EffectPlasticizer action: Plasticity

Implementation Method 2

using a laminate sheet with a metal and resin layer for durability and thermal weldability

Methodology Applied
Scientific EffectThermal welding: Welding

Data Source

PatentEP2251921B1Curved battery cell, and a battery pack employing the same
Publication Date: 2018.02.14 LG CHEM LTD
  • EP2251921B1 patent drawingFigure 1~2
  • EP2251921B1 patent drawingFigure 3~4

AI summary

Disclosed herein is a battery cell configured such that an electrode assembly of a cathode / separator / anode stack structure is mounted in a changeable cell case in a state in which the electrode assembly is impregnated with an electrolyte, wherein the electrode assembly and the cell case are curved in the same direction on axial vertical sections thereof in a state in which opposite ends of the electrode assembly and opposite ends of the cell case are directed in the same direction about a middle part of the electrode assembly and a middle part of the cell case. When the battery cell is mounted in an electronic device the external shape of which is curved or in an electronic device configured such that a battery mounting region thereof is curved, the tight contact between the battery cell and the electronic device is achieved, thereby maximizing space utilization and thus providing high efficiency. Also, electronic devices having aesthetically pleasing appearance and various designs satisfying liking of consumers are developed using the battery cell.