Battery Cell Assembly Layout for Current Balancing and Fault Isolation

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Solution Overview

Problem

Existing electrochemical cell assemblies face issues with oversized power connections leading to heating and difficulty in isolating faulty cells, especially in configurations where multiple cells are connected in parallel, which can cause external short circuits.

Innovation Solution

The assembly connects electrochemical elements in a series arrangement with balancing electrical connections that allow for easy isolation of faulty cells, using undersized connections to manage current flow and reduce heating, while maintaining electrical balance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If power connections are oversized to allow flow of sum of currents in parallel cells, then current carrying capacity is improved, but heating increases and space is wasted

Engineering Contradiction:
Improvecurrent carrying capacityVSAvoidheating
Core Design Contradiction:
PowerVSTemperature

Solution Approach 1:

The patent segments the electrical connections into two distinct types: power connections that carry only the current of a single cell (I), and balancing connections that carry balancing currents (ΔI). This segmentation allows each connection type to be optimally sized for its specific function, preventing the need to oversize power connections for the sum of all parallel cell currents.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces balancing connections as intermediary elements that mediate between parallel cells. These balancing connections handle the balancing currents separately from the power connections, allowing the power connections to remain sized for single-cell current only, thus reducing heating while maintaining proper current distribution.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Power

If power connections are oversized, then current carrying capacity is improved, but device size increases

Engineering Contradiction:
Improvecurrent carrying capacityVSAvoiddevice size
Core Design Contradiction:
PowerVSVolume of moving object

Solution Approach 1:

The patent segments the electrical connections into two distinct types: power connections that carry only the current of a single cell (I), and balancing connections that carry balancing currents (ΔI). This segmentation allows each connection type to be optimally sized for its specific function, preventing the need to oversize power connections for the sum of all parallel cell currents.

Inventive Principle:
Principle #1Segmentation

3Reliability

If balancing connections are present to isolate faulty cells, then reliability is improved, but device complexity increases

Engineering Contradiction:
Improvefault isolation capabilityVSAvoidconnection complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the fault isolation function into separate balancing connections that are distinct from the power connections. When a cell fails, the balancing connections can be opened to isolate the faulty cell while leaving the power connections intact and functional. This extraction simplifies the overall system by allowing independent handling of power transmission and fault isolation functions.

Inventive Principle:
Principle #2Taking out (Extraction)

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 reduces heating and simplifies fault isolation, ensuring reliable operation by dissociating power and balancing currents, allowing for efficient and compact design without overheating or chain reactions.

Implementation Method 1

the balancing electrical connections nevertheless ensure adequate electrical balancing within each block of electrochemical elements in parallel, by dissociating the power electrical currents passing through the power electrical connections and the balancing electrical currents passing through the balancing electrical connections

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

each block of electrochemical elements of said row of the K columns being electrically connected with the block(s) of electrochemical elements of said i-th row of the adjacent electrochemical column(s) by first electrical power connections connecting in series respectively the M electrochemical elements

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP4579991A1Electrochemical cell arrangement with optimised current circulation and battery for same
Publication Date: 2025.07.02 SAFT GRP SA
  • EP4579991A1 patent drawingFigure 1
  • EP4579991A1 patent drawingFigure 2
  • EP4579991A1 patent drawingFigure 3

AI summary

The assembly comprises blocks (18) of electrochemical elements (12) electrically connected in series in the following manner: - the blocks (18) of the i-th row (16) of K columns (14) are electrically connected to each other in series, the blocks (18) of the i-th row forming an i-th group (22) of blocks (18) of electrochemical elements (12) of the i-th row; - for each i-th row, each block (18) of said row of columns (14) is electrically connected with the block(s) (18) of said i-th row of the adjacent electrochemical column(s) (14) by first electrical power connections (20) connecting in series respectively the M electrochemical elements (12) of said block (18) with respectively the M electrochemical elements (12) of the block(s) of said row of the adjacent electrochemical column(s) (14).