Semi-Metal Oxide Anode Composite for Battery Cycle Life

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Solution Overview

Problem

Lithium secondary batteries face safety concerns due to high energy density, and high-capacity anode materials like silicon suffer from volume expansion and degraded cycle characteristics, particularly when mixed with graphite.

Innovation Solution

A composite is created by dispersing a conductive material in an aqueous binder and mixing it with a semi-metal oxide, which is then combined with a carbon material and a non-aqueous binder to enhance electrical conductivity and improve the performance and lifetime of secondary batteries.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If high-capacity anode materials like silicon are used, then capacity increases, but volume expansion and cycle characteristics degrade

Engineering Contradiction:
ImprovecapacityVSAvoidcycle characteristics
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The silicon particles are embedded within a porous carbon matrix structure, creating a nested configuration where the carbon matrix surrounds and contains the silicon particles. This nested structure allows the silicon to expand and contract during cycling while being constrained by the carbon matrix, preventing volume expansion issues and maintaining cycle characteristics while preserving high capacity.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The invention uses a composite structure combining silicon particles with carbon matrix and conductive material. This composite material approach allows the silicon to provide high capacity while the carbon matrix provides structural stability and the conductive material ensures electrical conductivity, thereby improving cycle characteristics without sacrificing capacity.

Inventive Principle:
Principle #40Composite materials

2Stability of the object's composition

If silicon or Si alloy is mixed with graphite, then volume expansion is reduced, but graphite distribution becomes non-uniform and cycle characteristics degrade

Engineering Contradiction:
Improvevolume expansionVSAvoidgraphite distribution uniformity
Core Design Contradiction:
Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The invention creates a localized carbon matrix structure that is specifically designed to surround and support silicon particles. Rather than uniform mixing of graphite and silicon, the carbon matrix is locally formed around each silicon particle, ensuring proper distribution and contact. This local quality approach ensures both volume expansion control and uniform distribution, improving cycle characteristics.

Inventive Principle:
Principle #3Local quality

3Reliability

If conductive material is dispersed in aqueous binder and mixed with semi-metal oxide, then electrical conductivity improves, but manufacturing complexity increases

Engineering Contradiction:
Improveelectrical conductivityVSAvoidmanufacturing process
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The conductive material is pre-dispersed in the aqueous binder to form a conductive slurry before mixing with the semi-metal oxide particles. This preliminary action ensures that the conductive material is already evenly distributed in the binder, so when the oxide particles are added, they are immediately coated with the conductive mixture. This approach improves electrical conductivity while avoiding the need for complex post-processing 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

The composite significantly improves electrical conductivity and extends the lifetime characteristics of secondary batteries, making them more suitable for high-capacity applications while maintaining economic efficiency.

Implementation Method 1

dispersing a conductive material in an aqueous binder

Methodology Applied
Scientific EffectDispersion: Dispersion (of waves)

Implementation Method 2

a binder

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentUS9806335B2Composite including conductive material and binder on surface of (semi) metal oxide and method of preparing anode slurry including the same
Publication Date: 2017.10.31 LG ENERGY SOLUTION LTD

AI summary

Provided are a composite and a method of preparing an anode slurry including the same. More particularly, the present invention provides a composite including a (semi) metal oxide, a conductive material on a surface of the (semi) metal oxide, and a binder, and a method of preparing an anode slurry including preparing a composite by dispersing a conductive material in an aqueous binder and then mixing with a (semi) metal oxide, and mixing the composite with a carbon material and a non-aqueous binder.