Positive Electrode Composite With Alkali Oxide for Battery Swelling Control

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Solution Overview

Problem

Lithium ion secondary batteries face issues with the continuous expansion and contraction of the negative electrode material due to lithium ion intercalation/deintercalation, leading to destruction of the SEI film, increased expansion force, and reduced cell life and safety performance.

Innovation Solution

Incorporating an alkali metal oxide, such as Na6FeO4 or K6FeO4, into the positive electrode composite material to reduce or eliminate the expansion/contraction deformation of the negative electrode, thereby reducing side reactions and expansion force, and enhancing cell life and safety performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If lithium ion secondary batteries use conventional positive electrode materials, then the battery can operate with basic performance, but the negative electrode material continuously expands and contracts during charging/discharging, leading to SEI film destruction and increased expansion force that reduces cell life and safety

Engineering Contradiction:

Improvecell life and safety performanceVSAvoidexpansion force and SEI film destruction

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces an alkali metal oxide (AmGOn) as an intermediary substance in the positive electrode composite material. This intermediary releases alkali metal ions (Na⁺, K⁺) that insert into the negative electrode material, acting as spacers to prevent particle rearrangement and reduce expansion force. The alkali metal oxide mediates between the positive and negative electrodes to eliminate the harmful effects of negative electrode expansion without requiring changes to the negative electrode structure itself.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the chemical composition parameter of the positive electrode by incorporating alkali metal oxides with specific formulas (AmGOn where A=Na, K, Li and G=Fe, Ni, Co, Mn, etc.). This parameter change enables the release of alkali metal ions that have different ionic radii than lithium ions, creating a structural effect where the larger alkali metal ions permanently expand the negative electrode lattice and prevent the cyclic expansion/contraction that causes SEI film destruction.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If the negative electrode material undergoes repeated intercalation/deintercalation of lithium ions, then the battery can charge and discharge, but the continuous expansion/contraction causes particle rearrangement and increases negative electrode thickness, leading to higher expansion force

Engineering Contradiction:

Improvecharging/discharging capabilityVSAvoidnegative electrode thickness and expansion force

Core Design Contradiction:

ProductivityVSLength of stationary object

Solution Approach 1:

The patent applies preliminary action by having the alkali metal ions insert into the negative electrode material during the initial stages of battery operation, before the harmful cyclic expansion/contraction fully develops. This preliminary insertion of larger alkali metal ions creates a pre-expanded structure that accommodates subsequent lithium ion cycles without significant additional expansion, thereby preventing particle rearrangement and limiting negative electrode thickness increase from the outset.

Inventive Principle:

Principle #10Preliminary action

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 use of alkali metal oxides in the positive electrode composite material effectively reduces the expansion force and improves the cycling life and safety performance of lithium ion secondary batteries by minimizing SEI film destruction and maintaining high energy density.

Implementation Method 1

the Na ions and/or K ions of a larger ionic radius are used to open the negative electrode material, reduce or eliminate the expansion/contraction deformation of the negative electrode material due to the repeated intercalation/deintercalation of the lithium ions

Methodology Applied

Scientific EffectIon insertion/expansion effect:

Implementation Method 2

reduce or eliminate the destruction of the SEI film caused by the deformation of the negative electrode material, reduce the side reactions

Methodology Applied

Scientific EffectSEI film stabilization:

Data Source

PatentUS20230352680A1Positive electrode composite material for lithium ion secondary battery, positive electrode and battery

Publication Date: 2023.11.02 CONTEMPORARY AMPEREX TECHNOLOGY (HONG KONG) LIMITED

AI summary

A positive electrode composite material for a lithium ion secondary battery, and a positive electrode using the positive electrode composite material for a lithium ion secondary battery, a lithium ion secondary battery and a power consuming device are provided. The positive electrode composite material for a lithium ion secondary battery comprises a positive electrode active material and an alkali metal oxide as shown by formula AmGOn, wherein A represents at least one element selected from Na and K and optionally Li, G represents at least one element selected from Fe, Ni, Co, Mn, Ru, Ir, Sn, Cr, Nb, Mo, V and Ti, m is 1-6, and n is 1-4.