Al-O Bonded Silicon Anode Conductivity
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Solution Overview
Problem
There is a need for a new silicon material with improved conductivity for use as a negative electrode active material in secondary batteries, as existing silicon materials face challenges with charge carrier occlusion and release, and silicon materials without Al addition suffer from reduced capacity and increased deterioration due to oxidation.
Innovation Solution
A negative electrode active material is developed using an Al- and O-containing silicon material with a specific range of Al content (0<WAl<1) that forms Al—O bonds, enhancing conductivity and reducing oxidation of silicon, thereby improving battery performance and longevity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If silicon material is used as negative electrode active material, then high capacity is achieved, but conductivity is insufficient and resistance is high
Solution Approach 1:
The patent changes the chemical composition parameters of silicon material by adding aluminum and oxygen to form Al-O bonds, which fundamentally alters the electrical properties. This parameter change transforms the material from poor conductor to material with sufficient conductivity for battery application while retaining high charge carrier capacity.
Solution Approach 2:
The patent creates a composite material system where aluminum and oxygen are incorporated into the silicon structure to form Al-O bonds. This composite approach combines the high capacity of silicon with the conductivity enhancement from Al-O bonding, resolving the contradiction between capacity and conductivity.
2Device complexity
If silicon material is used without Al addition, then simplicity is maintained, but oxidation occurs and deterioration increases
Solution Approach 1:
Aluminum acts as an intermediary element that bonds with oxygen to form Al-O bonds, preventing direct oxidation of silicon. This intermediary approach protects the silicon material from harmful oxidation while maintaining relative compositional simplicity.
Solution Approach 2:
The patent converts the harmful presence of oxygen (which would oxidize and deteriorate silicon) into a beneficial Al-O bond structure. By incorporating oxygen through Al addition, the material gains oxidation resistance and improved conductivity, turning potential harm into benefit.
3Reliability
If Al is added to silicon material, then conductivity increases and oxidation resistance improves, but material composition becomes more complex
Solution Approach 1:
The patent optimizes the concentration parameters of Al and O in the silicon material to achieve the desired balance. By controlling the amount of Al addition and the formation of Al-O bonds, the material achieves improved conductivity and oxidation resistance with controlled compositional complexity.
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 Al- and O-containing silicon material achieves low resistance and extended life for secondary batteries by maintaining charge carrier capacity and reducing silicon oxidation, making it suitable for lithium ion secondary batteries and other energy storage devices.
Implementation Method 1
the silicon material was found to have Al—O bonds
Implementation Method 2
reducing oxidation of silicon
Data Source
AI summary
A new silicon material is provided.A negative electrode active material including an Al- and O-containing silicon material, the Al- and O-containing silicon material being configured such that a mass % of Al (WAl %) satisfies 0<WAl<1, and a peak indicating Al—O bond is observed in a range of 1565 to 1570 eV in an X-ray absorption fine structure measurement for a K shell of Al.