Carbon-Silicon Anode Composition for High-Loading Fast-Charge Cells
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Solution Overview
Problem
Existing rechargeable batteries face challenges in achieving high capacity loading without compromising electrode performance, particularly in terms of capacity, fast charging, and long cycle stability, due to unclear optimal composite formulations and processing methods for carbon-based composite particles.
Innovation Solution
A lithium-ion battery anode composition is developed using a porous composite particle comprising carbon and silicon, characterized by specific domain sizes and ratios, as determined by synchrotron x-ray diffraction, to enhance electrode performance and capacity loading.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If carbon and silicon composite particles are used to increase capacity loading, then energy density is improved, but electrode performance deteriorates due to unclear optimal formulations
Solution Approach 1:
The patent applies parameter changes by precisely controlling the carbon domain size (r) within the specific range of 10-60 Å as determined by atomic pair distribution function analysis. This parameter optimization resolves the contradiction by establishing that carbon domains within this specific size range provide both high capacity loading and maintained electrode performance, whereas deviating from this range causes performance deterioration. The systematic variation and control of the carbon domain size parameter enables simultaneous achievement of high silicon content (improving capacity) and stable electrochemical performance.
Solution Approach 2:
The patent employs composite materials by creating a sophisticated carbon-silicon composite structure where carbon domains are embedded within a matrix containing silicon particles. This composite architecture allows the carbon phase to provide structural stability and electrical conductivity while the silicon phase contributes high capacity. The specific carbon domain size control ensures optimal interaction between the carbon and silicon phases, resolving the formulation uncertainty by establishing that carbon domains of 10-60 Å create the most effective composite structure for maintaining performance at high capacity loadings.
2Quantity of substance
If higher capacity loading is achieved, then energy density improves, but fast charging capability deteriorates
Solution Approach 1:
The patent applies local quality by creating non-uniform carbon domain distributions within the composite particles. The carbon domains with sizes of 10-60 Å are strategically positioned and sized to create local conductive networks that facilitate rapid ion and electron transport. This local optimization of carbon domain characteristics ensures that even at high areal capacity loadings, the electrode maintains fast charging capability through enhanced local conductivity pathways that enable rapid charge acceptance without requiring uniform structural changes throughout the entire electrode.
3Quantity of substance
If higher capacity loading is achieved, then energy density improves, but cycle stability deteriorates
Solution Approach 1:
The patent applies beforehand cushioning by incorporating carbon domains of 10-60 Å that act as preventive structural elements against degradation mechanisms. These carbon domains serve as a cushioning matrix that accommodates volume changes of silicon during cycling, preventing particle fracture and maintaining structural integrity. The specific size range of carbon domains provides optimal mechanical cushioning that absorbs stress and strain during charge-discharge cycles, thereby protecting the electrode structure and maintaining cycle stability even at high areal capacity loadings where degradation would typically accelerate.
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 anode composition achieves improved areal capacity loading, fast charging, and long cycle stability, contributing to higher energy density and reduced manufacturing costs.
Implementation Method 1
a lithium-ion battery anode composition includes a porous composite particle comprising carbon (C) and an active material comprising silicon (Si)
Implementation Method 2
anode composition achieves improved areal capacity loading, fast charging, and long cycle stability
Implementation Method 3
the carbon is characterized by a domain size (r), as estimated from an atomic pair distribution function G(r) obtained from a synchrotron x-ray diffraction measurement
Implementation Method 4
obtained from a synchrotron x-ray diffraction measurement of the porous composite particle
Data Source
Figure 1
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Figure 2B
AI summary
In an aspect, a lithium-ion battery anode composition comprises a porous composite particle comprising carbon (C) and an active material comprising silicon (Si), wherein the carbon is characterized by a domain size (r), as estimated from an atomic pair distribution function G(r) obtained from a synchrotron x-ray diffraction measurement of the porous composite particle, ranging from around 10 Å (1 nm) to around 60 Å (6 nm). In a further aspect, a carbon material for use in making an anode composition for use in a Li-ion battery is characterized by a domain size (r), as estimated from an atomic pair distribution function G(r) obtained from a synchrotron x-ray diffraction measurement of the carbon material, ranging from around 10 Å (1 nm) to around 60 Å (6 nm).