Aggregated Carbon Scaffolds for Silicon–Carbon Composite Particles

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Solution Overview

Problem

Existing methods for producing silicon-carbon composite materials for lithium-ion batteries face challenges in achieving amorphous nano-sized silicon distribution within porous carbon scaffolds, leading to electrode deterioration and cycle stability issues due to silicon expansion, while also being costly and complex.

Innovation Solution

A process involving chemical vapor infiltration (CVI) of silicon-containing gases into agglomerated porous carbon scaffolds, using agglomerated carbon materials with Dv50 greater than 1 mm, to impregnate amorphous nano-sized silicon within the pores, overcoming handling and reactor design limitations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If porous carbon scaffolding materials with small particle size are used to achieve good infiltration of silicon precursor gas, then silicon impregnation efficiency is improved, but material handling becomes difficult and reactor design becomes complex

Engineering Contradiction:

Improvesilicon impregnation efficiencyVSAvoidmaterial handling

Core Design Contradiction:

ProductivityVSEase of operation

Solution Approach 1:

The porous carbon material is divided into particles with specific size range (0.1-1.0 mm) that can be easily handled while maintaining good infiltration properties. The segmentation of particle size allows balancing between infiltration efficiency and handling ease.

Inventive Principle:

Principle #1Segmentation

2Productivity

Engineering Contradiction:

Improvesilicon impregnation efficiencyVSAvoidreactor design

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

Inventive Principle:

Principle #1Segmentation

3Reliability

If silicon particle size is reduced to accommodate expansion during lithiation, then cycle stability is improved, but electrode deterioration occurs due to pulverization

Engineering Contradiction:

Improvecycle stabilityVSAvoidelectrode integrity

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The porous carbon scaffold provides pre-established void space that acts as a cushion to accommodate silicon expansion during lithiation. This beforehand cushioning prevents particle pulverization and maintains electrode integrity while allowing cycle stability.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

A porous carbon scaffold material with controlled porosity (30-70% void volume) is used to create a matrix that can absorb expansion stress. The porous structure allows silicon particles to expand without causing pulverization, maintaining both cycle stability and electrode strength.

Inventive Principle:

Principle #31Porous materials

4Reliability

If amorphous carbon is used as coating for silicon anode materials to improve conductivity and buffer expansion, then electrochemical performance is improved, but core-shell structure destruction occurs due to lack of engineered void space

Engineering Contradiction:

Improveelectrochemical performanceVSAvoidcore-shell structure integrity

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

Instead of coating silicon with carbon to create core-shell structure, the invention inverts the approach by embedding silicon within a porous carbon scaffold matrix. This inversion provides the necessary void space from the beginning, preventing structure destruction while maintaining electrochemical performance.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

Inventive Principle:

Principle #31Porous materials

Data Source

PatentUS20250333842A1Chemical vapor infiltration of aggregated scaffolding materials to produce composite particulate materials

Publication Date: 2025.10.30 GROUP14 TECHNOLOGIES INC

AI summary

Silicon-carbon composite materials and related processes that overcome the challenges for providing amorphous nano-sized silicon entrained within porous carbon. Agglomerated porous carbon is used during a composite creation process.