Battery Cell Stack Volume Control for Swelling-Space Tradeoffs

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Solution Overview

Problem

Existing battery technologies face safety issues due to insufficient expansion space leading to mutual compression of battery cells, which can cause hazardous situations, and reserving large expansion space reduces energy density and capacity.

Innovation Solution

A battery assembly where battery cells are sequentially stacked, with their volumes correlated to charge, allowing controlled volume changes within preset ranges to maintain safety and reduce expansion space requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If insufficient expansion space is reserved for battery cells, then the energy density and capacity of the battery are improved, but the safety of battery use deteriorates due to mutual compression of battery cells

Engineering Contradiction:
Improveenergy densityVSAvoidsafety
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The battery assembly is divided into multiple battery units, each comprising multiple battery cells arranged in series. This segmentation allows independent volume control of each unit through coordinated charging and discharging operations, enabling the total volume change to be maintained within a preset range while maximizing energy density.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic charge-discharge control where battery units are selectively charged or discharged based on real-time volume monitoring. When the total volume of battery units exceeds the preset range, the control unit adjusts the charge-discharge states of individual units to maintain volume within acceptable limits, thereby ensuring safety without requiring excessive expansion space.

Inventive Principle:
Principle #15Dynamics

2Reliability

If a large amount of expansion space is reserved for battery cells, then the safety of battery use is improved, but the energy density and capacity of the battery deteriorate

Engineering Contradiction:
ImprovesafetyVSAvoidenergy density
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The control unit pre-establishes a preset volume range for battery units and monitors real-time volume changes. By taking preliminary control actions through coordinated charge-discharge operations before hazardous compression occurs, the system maintains safety without requiring large static expansion spaces, thereby preserving energy density.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the operational parameters of battery units by dynamically adjusting their charge-discharge states. This parameter control enables the total volume of battery units to be maintained within a preset range, allowing minimal expansion space reservation while ensuring safety, thus improving energy density without compromising reliability.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If the charge of battery cells changes individually, then the volume of each battery cell changes, but the total volume change exceeds the preset range causing hazardous situations

Engineering Contradiction:
Improvecharge flexibilityVSAvoidhazardous situations
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The control unit continuously monitors the total volume of battery units and provides feedback control. When volume changes indicate potential hazardous compression, the system adjusts the charge-discharge states of individual battery units to bring the total volume back within the preset range, thereby preventing hazardous situations while maintaining charge flexibility.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The control unit acts as an intermediary that coordinates the charge-discharge operations of multiple battery units. By mediating the charge changes of individual cells through controlled charge-discharge cycles, the system ensures that total volume changes remain within safe limits while preserving the adaptability of individual cell charge states.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP4704215A1Battery assembly, battery, electric apparatus, and control method for battery assembly
Publication Date: 2026.03.04 CONTEMPORARY AMPEREX TECHNOLOGY CO LTD
  • EP4704215A1 patent drawingFigure 1~2
  • EP4704215A1 patent drawingFigure 3~4
  • EP4704215A1 patent drawingFigure 5~6

AI summary

A battery assembly (30) and a control method thereof, a battery (100), and an electric apparatus are provided, where the battery assembly (30) includes: M battery cells (20), the M battery cells (20) being sequentially stacked along a first direction, where M is an integer greater than 1; and a volume of each battery cell (20) is positively correlated with a remaining charge of the battery cell, so that when a charge of at least one battery cell (20) among the M battery cells (20) changes, a total volume change of the M battery cells (20) is maintained within a first preset range.