Secondary Battery Lead Assembly for Overcharge Shutdown

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Lithium secondary batteries face safety risks due to overcharging, which can lead to heat generation, thermal runaway, and explosion, with existing safety materials failing to provide adequate protection, especially in cases of rapid temperature changes or internal pressure increases.

Innovation Solution

An electrode assembly with a conducting wire and a temperature-sensitive part, such as a Nickel-Titanium alloy or bimetal, that connects the positive and negative electrode leads at high temperatures, coupled with a voltage measurer and controller to halt charging when a predetermined voltage is reached, preventing overcharging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If CID materials are used for safety protection, then temperature-based safety is improved, but they can only be applied to cylindrical batteries and cannot serve fast response requirements

Engineering Contradiction:

Improvetemperature-based safetyVSAvoidbattery type applicability

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent describes a safety material composition and embedding method that can be universally applied to various battery types including pouch, cylindrical, and prismatic batteries. The safety material is integrated into the electrode assembly structure in a way that accommodates different battery form factors, making the solution adaptable across multiple battery technologies rather than being limited to cylindrical configurations.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If electrolyte or additive is added to improve electrode safety, then safety protection is achieved without additional process or space, but battery performance degrades due to by-products or volume occupation

Engineering Contradiction:

Improveelectrode safetyVSAvoidbattery performance

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The safety material is applied locally at specific positions within the electrode assembly rather than being uniformly distributed throughout the entire battery. This localized application allows the safety material to provide protection where thermal runaway is most likely to initiate (at electrode interfaces and hot spots) while minimizing its impact on overall battery performance and capacity.

Inventive Principle:

Principle #3Local quality

3Reliability

If existing safety measures are implemented, then some level of protection is provided, but they fail to provide complete safety assurance against thermal runaway and explosion

Engineering Contradiction:

Improvesafety protection levelVSAvoidthermal runaway and explosion risk

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The safety material is pre-positioned within the electrode assembly before battery operation, creating a protective buffer in advance. During normal operation, the safety material remains dormant or minimally active. When thermal runaway begins, the safety material rapidly activates to absorb heat and release flame-retardant gases, cushioning the thermal event before it can propagate to cause explosion or fire.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

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 solution effectively prevents overcharging by immediately halting the charging process when high temperatures are detected, thereby enhancing the safety of lithium secondary batteries by preventing thermal runaway and explosion.

Implementation Method 1

the temperature-sensitive part may contain a shape memory alloy comprising a Nickel-Titanium alloy

Methodology Applied

Scientific EffectShape memory alloy effect: Shape Memory Alloy

Implementation Method 2

the temperature-sensitive part may contain a bimetal comprising a first metal consisting of a Nickel-Iron alloy; and a second metal consisting of a Nickel-Manganese-Iron alloy

Methodology Applied

Scientific EffectBimetallic strip effect: Bi-Metallic Strip

Implementation Method 3

a voltage measurer being electrically connected to a middle of the conducting wire

Methodology Applied

Scientific EffectVoltage measurement:

Implementation Method 4

halting the charging of the secondary battery if the voltage value received from the voltage measurer is greater than or equal to a predetermined value

Methodology Applied

Scientific EffectOvercharge protection:

Data Source

PatentUS20240055875A1Secondary battery capable of preventing overcharge, and charging method thereof

Publication Date: 2024.02.15 LG ENERGY SOLUTION LTD

AI summary

A secondary battery is capable of preventing overcharge. The secondary battery has a conducting wire that electrically connects a positive electrode lead and a negative electrode lead, introducing a temperature-sensitive part that changes in shape under high-temperature conditions to the negative electrode lead end side of the conducting wire, and by having a formation where the voltage between the positive electrode lead and the negative electrode lead is measured. The secondary battery can immediately halt the charging process when overcharging of the secondary battery occurs, which provides an advantage of better improving safety of the battery.