Cathode Active Material Mixing to Prevent Slurry Gelation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Increasing the nickel ratio in cathode active materials for lithium secondary batteries leads to excessive lithium remaining on the surface, causing issues with physical properties during the electrode mixing process and affecting battery performance, necessitating additional costly processes like water washing and heat treatment to control moisture.

Innovation Solution

A method involving the preparation of a lithium compound removal solution with polyacrylic acid (PAA) and a solvent to react with the cathode active material, removing lithium compounds, followed by mixing with conductive materials and binders, without additional processes, to maintain slurry stability and electrochemical performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the nickel ratio in cathode active material is increased to achieve higher energy density, then the energy formation is improved, but the amount of lithium remaining on the surface increases causing slurry physical property changes and battery performance degradation

Engineering Contradiction:

Improveenergy formationVSAvoidbattery performance

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The patent extracts and removes the harmful lithium compounds remaining on the surface of the cathode active material through a chemical treatment process using lithium compound removal solution, thereby eliminating the source of slurry instability and battery performance issues while preserving the high nickel content composition

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the chemical state of surface lithium compounds by reacting them with lithium compound removal solution containing specific reagents, transforming the harmful residual lithium into removable compounds that can be washed away, thus resolving the slurry stability problem without reducing nickel content

Inventive Principle:

Principle #35Parameter changes

2Stability of the object's composition

If water washing and heat treatment processes are added to remove lithium compounds and control moisture, then the slurry physical properties are stabilized, but the production cost of active materials and electrode manufacturing process increases

Engineering Contradiction:

Improveslurry physical propertiesVSAvoidproduction cost

Core Design Contradiction:

Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

The patent combines the lithium compound removal function and moisture control function into a single integrated treatment step using lithium compound removal solution, eliminating the need for separate water washing and heat treatment processes while achieving both stabilization objectives

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces lithium compound removal solution as an intermediary chemical agent that simultaneously removes lithium compounds and controls moisture content, replacing multiple expensive thermal and washing processes with a single chemical treatment step

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If additional processes like water washing and heat treatment are performed to control moisture and remove lithium compounds, then the battery performance is ensured, but the complexity of the manufacturing process increases

Engineering Contradiction:

Improvebattery performanceVSAvoidmanufacturing process complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent performs preliminary removal of lithium compounds from the cathode active material surface before the electrode mixing process, preventing slurry instability issues from occurring in the first place and eliminating the need for subsequent corrective washing and heat treatment steps

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

This method effectively removes lithium compounds, preventing slurry gelation and enhancing electrochemical properties, ensuring stable physical properties and improved battery performance without increasing production costs.

Implementation Method 1

reacting the lithium compound removal solution with the cathode active material, on a surface of which a lithium compound is present, thus removing the lithium compound present on the surface of the cathode active material

Methodology Applied

Scientific EffectChemical reaction: Chemical Bonding

Data Source

PatentUS11769880B2Method of mixing cathode active material

Publication Date: 2023.09.26 HYUNDAI MOTOR CO LTD

AI summary

A method of mixing a cathode active material in a process of manufacturing a cathode of a lithium secondary battery is provided. The method includes a preparation step of preparing a lithium compound removal solution in which PAA (polyacrylic acid) is mixed with a solvent, a removal step of reacting the lithium compound removal solution with the cathode active material, on a surface of which a lithium compound is present, thus removing the lithium compound present on the surface of the cathode active material, and a mixing step of mixing the cathode active material, which is mixed with the lithium compound removal solution, with a conductive material and a binder.