LixAl2(OH)7-y.zH2O Coating for Battery Thermal Stability

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Batteries face challenges in thermal stability, particularly when the positive electrode and negative electrode are short-circuited, leading to potential thermal runaway, and there is a need for improved thermal management as capacity and charging voltage increase.

Innovation Solution

A battery design incorporating a positive electrode material with LixAl2(OH)7-y.zH2O, which covers the surfaces of the positive electrode active material particles, enhancing thermal stability by providing endothermic properties that mitigate heat generation, and is characterized by specific crystallinity peaks in powder X-ray diffraction measurements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the positive electrode and negative electrode are short-circuited, then electrical connection is achieved, but thermal runaway may occur

Engineering Contradiction:

Improvethermal stabilityVSAvoidthermal runaway risk

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A coating layer comprising LixAl2(OH)7-y.zH2O is applied to the positive electrode active material particles. This coating layer acts as an intermediary substance between the positive electrode and negative electrode, preventing direct harmful interactions while allowing ionic conduction, thereby suppressing thermal runaway during short-circuit conditions

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The coating layer changes the thermal and chemical parameters of the positive electrode surface. By controlling the composition parameters (x, y, z in LixAl2(OH)7-y.zH2O) and applying heat treatment at 50°C to 150°C, the material exhibits enhanced thermal stability and endothermic properties that prevent thermal runaway

Inventive Principle:

Principle #35Parameter changes

2Quantity of substance

If single cell capacity and charging voltage are increased, then unit cell capacity is improved, but thermal stability becomes more critical and difficult to maintain

Engineering Contradiction:

Improveunit cell capacityVSAvoidthermal stability

Core Design Contradiction:

Quantity of substanceVSTemperature

Solution Approach 1:

The coating layer parameters (composition LixAl2(OH)7-y.zH2O and heat treatment temperature 50°C-150°C) are optimized to provide thermal stability while maintaining high capacity. The coating suppresses exothermic reactions and provides endothermic heat absorption, enabling the battery to achieve high unit cell capacity without compromising thermal stability

Inventive Principle:

Principle #35Parameter changes

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

The proposed solution significantly improves the thermal stability of the battery, reducing the risk of thermal runaway and maintaining discharge capacity within optimal LixAl2(OH)2O content ranges, thereby ensuring safer and more efficient battery performance.

Implementation Method 1

enhancing thermal stability by providing endothermic properties that mitigate heat generation

Methodology Applied

Scientific EffectEndothermic reaction: Endothermic Reaction

Implementation Method 2

characterized by specific crystallinity peaks in powder X-ray diffraction measurements

Methodology Applied

Scientific EffectX-ray diffraction: X-Ray

Data Source

PatentUS11011740B2Positive electrode material, positive electrode, battery, battery pack, electronic device, electric vehicle, electric storage device, and electric power system

Publication Date: 2021.05.18 MURATA MFG CO LTD

AI summary

A battery includes a positive electrode, a negative electrode, and an electrolyte. The positive electrode includes LixAl2(OH)7-y.zH2O where 0.9<x<1.1, −0.1<y<0.1, 0≤z<2.1.