Silicon Nanowire Growth on Conductive Grains for Stable Anodes

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Solution Overview

Problem

Current lithium-ion battery technology faces limitations due to the mechanical stress of silicon anodes during cycling, leading to electrode failure, and existing methods for producing silicon nanowires are complex, energy-intensive, and costly, hindering industrial application.

Innovation Solution

A method for manufacturing nanoelements, such as silicon nanowires, involves a heat treatment process at controlled temperatures under a non-oxidizing atmosphere, using a catalyst-decorated conductive grain mixture, allowing for easy and efficient production of nanowires suitable for energy storage elements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If silicon nanowires are used to improve battery capacity, then energy density increases, but mechanical stability deteriorates due to volume change during cycling

Engineering Contradiction:
Improveenergy densityVSAvoidmechanical stability
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The invention segments the silicon anode into numerous individual silicon nanowires (typically 1-100 nm in diameter) rather than using bulk silicon. This segmentation allows each nanowire to independently accommodate volume changes during lithium intercalation/deintercalation cycles, preventing the mechanical failure that occurs in bulk silicon structures. The nanoscale dimensions provide sufficient surface area while maintaining structural integrity through the segmented architecture.

Inventive Principle:
Principle #1Segmentation

2Manufacturing precision

If complex methods like SFLS are used to produce silicon nanowires, then nanowire quality improves, but manufacturing complexity and energy consumption increase

Engineering Contradiction:
Improvenanowire qualityVSAvoidmanufacturing complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The invention employs a self-assembly approach where silicon nanowires form spontaneously through a simple heat treatment process. A mixture containing silicon source material, catalyst particles, and binding agents is heated to a temperature where nanowires self-assemble and grow. This eliminates the need for complex equipment and multi-step processes like SFLS, achieving nanowire production through a single, straightforward thermal treatment that is easier to implement industrially.

Inventive Principle:
Principle #25Self-service

3Reliability

If high temperature heat treatment is applied to form carbon coating on nanowires, then nanowire stability improves, but energy consumption increases

Engineering Contradiction:
Improvenanowire stabilityVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The invention merges the nanowire formation process and the protective carbon coating formation into a single simultaneous heat treatment step. Rather than first synthesizing nanowires and then separately coating them at high temperature, the process uses one thermal treatment to accomplish both tasks: the catalyst particles facilitate nanowire growth while the binding agent forms the protective carbon coating. This combined approach reduces total energy consumption compared to sequential high-temperature processes.

Inventive Principle:
Principle #5Merging (Combining)

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 method enables the production of silicon nanowires with improved mechanical stability and conductivity, facilitating industrial-scale production of high-capacity energy storage elements with reduced energy and cost, suitable for lithium-ion batteries and supercapacitors.

Implementation Method 1

a heat treatment process at controlled temperatures under a non-oxidizing atmosphere, using a catalyst-decorated conductive grain mixture, allowing for easy and efficient production of nanowires

Methodology Applied
Scientific EffectCatalysis: Catalysis

Implementation Method 2

The heat treatment step applied to the mixture can be carried out at a temperature between 270°C and 600°C, and preferably between 270°C and 450°C

Methodology Applied
Scientific EffectThermal energy transformation: Heating

Data Source

PatentEP3281244B1Method for manufacturing a material having nanoelements
Publication Date: 2025.08.20 COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
  • EP3281244B1 patent drawingFigure 1~2
  • EP3281244B1 patent drawingFigure 3~4

AI summary

The invention relates to a method for manufacturing a material (1) containing nanoelements (2), including the following steps: forming (E2) a mixture (6) containing a plurality of electrically conductive grains (3), a catalyst (4) which is separate from the grains (3) of the plurality of electrically conductive grains, and a reagent (7) that is in the form of a liquid or suspension of solid particles in a liquid solvent and contains a precursor of the material for forming the nanoelements (2); placing the mixture (6) into a chamber of a reactor and setting the reactor at a pressure of no higher than 1 bar; and obtaining (E3) the material (1) from the mixture (6). Said obtaining step includes a step (E3-1) of growing said nanoelements (2) using the catalyst (4) which is now associated with said grains (3) of the plurality of electrically conductive grains. Said growth step (E3-1) is implemented by a step for heat treatment applied to said mixture (6).