Wound Battery Electrode Segmentation for Short-Circuit Safety

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Solution Overview

Problem

Batteries with wound structures face safety issues due to short circuits caused by external scratches, as existing configurations do not effectively manage short-circuit currents, leading to potential thermal runaway.

Innovation Solution

A battery design where the positive electrode is divided into multiple electrodes adjacent in the winding direction, with current collecting leads electrically connected outside the exterior material, reducing short-circuit current resistance and improving safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the positive electrode is divided into multiple electrodes with separate current collecting leads, then safety against short circuits is improved, but device complexity increases

Engineering Contradiction:

Improvesafety against short circuitsVSAvoidelectrode structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The positive electrode is divided into multiple independent electrodes (first positive electrode and second positive electrode), each with its own current collecting lead. This segmentation allows independent current collection paths, so that a short circuit in one electrode does not necessarily affect the other electrodes, thereby improving safety while managing complexity through modular design

Inventive Principle:

Principle #1Segmentation

2Reliability

If current collecting leads are electrically connected outside the exterior material, then short-circuit current resistance is reduced, but the risk of external short circuits increases

Engineering Contradiction:

Improveshort-circuit current resistanceVSAvoidexternal short circuit risk

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A current collecting member is introduced as an intermediary component to connect the first and second current collecting leads outside the exterior material. This intermediary provides a controlled and protected connection point, reducing resistance for short-circuit currents while managing the external connection risk through a dedicated structural element

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If multiple current collecting leads are provided, then safety is improved, but manufacturing complexity increases

Engineering Contradiction:

ImprovesafetyVSAvoidmanufacturing complexity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The current collecting leads from multiple electrodes are merged and connected through a common current collecting member located outside the exterior material. This merging approach reduces the number of separate connection points needed, simplifying the manufacturing process while maintaining the safety benefits of multiple electrodes

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS11335958B2Battery, battery pack, electronic apparatus, electric vehicle, power storage device and power system

Publication Date: 2022.05.17 MURATA MFG CO LTD

AI summary

A battery includes an electrode body having a positive electrode and a negative electrode, in which the positive electrode and the negative electrode are wound; and an exterior material that accommodates the electrode body, in which at least one of the positive electrode and the negative electrode is divided into two or more electrodes adjacent in a winding direction, the two or more of electrodes each have a current collecting lead, and the current collecting leads are electrically connected to each other at a position outside the exterior material.