Silicon-Carbon Anode Composite for High-Capacity Battery Processing

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Solution Overview

Problem

Existing lithium secondary batteries face limitations in energy density due to the use of graphite as a negative electrode active material, and silicon-based materials, while promising, suffer from capacity and efficiency issues and process compatibility problems.

Innovation Solution

A silicon carbon composite with specific 13C-NMR peak ratios and a carbon layer on the surface, optimized to improve capacity, efficiency, and process compatibility, is used as a negative electrode active material.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If graphite is used as negative electrode active material, then discharge voltage is high (3.6 V), but energy density is limited due to low capacity

Engineering Contradiction:

ImprovecapacityVSAvoidenergy density

Core Design Contradiction:

Quantity of substanceVSUse of energy by moving object

Solution Approach 1:

The patent uses a composite material consisting of silicon particles embedded in a carbon matrix. The silicon provides high capacity while the carbon matrix maintains structural integrity and enables electrical conductivity, achieving both high capacity and energy density simultaneously

Inventive Principle:

Principle #40Composite materials

2Quantity of substance

If silicon-based active materials are used, then capacity and efficiency are high, but process compatibility problems occur with aqueous binders

Engineering Contradiction:

ImprovecapacityVSAvoidprocess compatibility

Core Design Contradiction:

Quantity of substanceVSEase of manufacture

Solution Approach 1:

The carbon matrix acts as an intermediary between the silicon particles and the aqueous binder. It provides a compatible interface that allows aqueous binders to effectively bind the electrode components while the silicon particles maintain their high capacity characteristics

Inventive Principle:

Principle #24Intermediary (Mediator)

3Quantity of substance

If silicon-based active materials are used, then capacity is high, but gas generation problems occur

Engineering Contradiction:

ImprovecapacityVSAvoidgas generation

Core Design Contradiction:

Quantity of substanceVSObject-generated harmful factors

Solution Approach 1:

The patent converts the harmful gas generation by silicon into a beneficial process by controlling the formation cycle. The initial gas generation is managed through a controlled formation process that creates a stable SEI layer, transforming the harmful effect into a controlled process that enables high capacity performance

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Data Source

PatentEP4707237A1Silicon carbon composite, negative electrode active material, negative electrode composition, negative electrode, and secondary battery

Publication Date: 2026.03.11 LG ENERGY SOLUTION LTD

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AI summary

The present invention relates to: a silicon carbon composite having a peak A present in a range of 130 ppm to 150 ppm, a peak B present in a range of 110 ppm to 130 ppm, and a peak C present in a range of 15 ppm to 40 ppm during 13C-NMR analysis, and satisfying equation 1 below; a negative electrode active material comprising same; a negative electrode composition; a negative electrode; a lithium secondary battery; a battery module; and a battery pack. [Equation 1] 0.3 ≤ peak C intensity/(peak A intensity + peak B intensity) ≤ 2.1.