Battery Cell Switching Device for Cascading Failure Mitigation

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Solution Overview

Problem

Battery cells in motor vehicles face safety and availability issues due to production-related fluctuations in capacity and internal resistance, leading to potential damage from deep discharge or overcharge, which can cause failure of individual cells and disrupt the entire battery system, especially in series connections.

Innovation Solution

A battery cell design incorporating a galvanic element with a sensor device for detecting physical and chemical properties, a control device to manage these properties, and a switching mechanism to bridge faulty cells, ensuring safe operation and maintaining battery functionality by bypassing damaged cells in series connections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If battery cells are connected in series to provide high voltage, then the voltage output is improved, but the reliability deteriorates because damage to a single cell causes failure of the entire battery

Engineering Contradiction:
Improvevoltage outputVSAvoidbattery system reliability
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The battery system is segmented into multiple independently controllable battery cells, each equipped with its own switching device. This allows individual cells to be isolated or bypassed without affecting the operation of other cells, thereby maintaining system reliability while preserving high voltage output capability through series connection.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Switching devices are introduced as intermediary components between battery cells and the electrical load. These switching devices act as mediators that can selectively connect or disconnect individual cells from the circuit, preventing a single cell failure from propagating to the entire battery system while maintaining the series connection architecture for high voltage output.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If individual battery cells are monitored with sensor devices, then the reliability is improved by detecting damage early, but the device complexity increases

Engineering Contradiction:
Improvebattery cell monitoring reliabilityVSAvoidsensor and control system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Each battery cell is equipped with integrated sensor devices that autonomously monitor its own physical and chemical properties. The control device evaluates data from these sensors and automatically activates switching devices to isolate faulty cells, enabling the system to self-diagnose and self-protect without external intervention, thereby improving reliability while keeping the added complexity manageable through automation.

Inventive Principle:
Principle #25Self-service

3Manufacturing precision

If battery cells with varying capacity and internal resistance are charged at the same rate, then the manufacturing precision requirements are reduced, but the reliability deteriorates due to deep discharge or overcharge damage

Engineering Contradiction:
Improvebattery cell production toleranceVSAvoidbattery cell durability
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The charging system employs dynamic control through individual switching devices for each battery cell, allowing the charging current to be dynamically adjusted or redirected based on real-time cell conditions. This dynamic approach enables cells with varying capacities and internal resistances to be charged at appropriate rates, preventing overcharge or deep discharge damage while accommodating broader manufacturing tolerances.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3259797B1Battery cell for a battery of a motor vehicle, battery and motor vehicle
Publication Date: 2020.09.16 AUDI AG
  • EP3259797B1 patent drawingFigure 1

AI summary

The invention relates to a battery cell (1) for a battery of a motor vehicle comprising a galvanic element (2) with a first electrode (4) and a second electrode (5), a battery cell housing (3) with a first connection (6) and a second connection (7), at least one sensor device (9, 10, 11, 2, 13, 14, 15, 16, 17, 18) for determining a physical and/or chemical characteristic of the battery cell (1), and a control device (19), wherein the galvanic element (2) is arranged in the battery cell housing (3), wherein the battery cell (1) has a switching device (S) by means of which the first connection (6) and the second connection (7) can be electrically connected, and the control device (19) is designed to close the switching device (S) for the purpose of shorting the battery cell (1), in accordance with the physical and/or chemical characteristic determined by the at least one sensor device (9, 10, 11, 12, 13, 4, 15, 16, 17, 18). The invention also relates to a battery and a motor vehicle.