Boron-Doped SiCx Anode Material for Stable Silicon Battery Cycling
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Solution Overview
Problem
Existing silicon-based negative electrode materials for lithium secondary batteries suffer from irreversible reactions, low electrical conductivity, and excessive volume changes during charging and discharging, leading to poor initial efficiency, capacity, and lifespan characteristics.
Innovation Solution
A negative electrode active material comprising silicon-carbon-based particles with a SiC x matrix doped with boron, where x is 0.3 or more and less than 0.6, is used to minimize irreversible reactions and improve electrical conductivity and mechanical stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If silane-modified polyethylene crosslinked granular carbon is used as negative electrode active material, then battery output characteristics are improved, but internal stress during charging/discharging increases causing electrode deterioration
Solution Approach 1:
The patent applies local quality by creating a core-shell structure where the inner core maintains high Li-ion reactivity for power output, while the outer shell provides structural stability and stress resistance. This spatial differentiation of material properties resolves the contradiction between achieving high power output and maintaining electrode structural stability during charging/discharging cycles.
Solution Approach 2:
The patent uses composite materials by combining silane-modified polyethylene crosslinked granular carbon with specific binders and conductive agents in a core-shell configuration. This composite structure enables the electrode to simultaneously achieve improved output characteristics through the reactive core while resisting internal stress through the stabilizing shell and binder system.
2Productivity
If conventional mixing methods are used to prepare slurry, then manufacturing process is simple, but uniform distribution of active material and binder is poor leading to low production efficiency
Solution Approach 1:
The patent applies preliminary action by pre-modifying the carbon particles with silane groups and pre-forming the core-shell structure before final electrode assembly. This preliminary preparation ensures uniform distribution characteristics are built into the material structure itself, which then translates to consistent slurry formation and high production efficiency during electrode manufacturing.
Solution Approach 2:
The patent changes material parameters by introducing silane modification to the polyethylene crosslinked carbon, altering its surface properties and reactivity. This parameter change enables better dispersion characteristics in the slurry and improves the uniformity of active material distribution throughout the electrode, directly enhancing both manufacturing precision and production efficiency.
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 SiC x matrix with boron doping enhances the battery's initial efficiency, capacity, and lifespan by reducing irreversible phase generation and volume expansion, while maintaining high electrical conductivity.
Implementation Method 1
silane-modified polyethylene crosslinked granular carbon for negative electrodes, wherein the silane-modified polyethylene crosslinked granular carbon is formed by crosslinking silane-modified polyethylene granules in the presence of carbon particles
Data Source
AI summary
A negative electrode active material including a silicon-carbon-based particle, the silicon-carbon-based particle having a SiCx matrix and boron doped in the SiCx matrix, wherein x of the SiCx matrix is 0.3 or more and less than 0.6.