Silicon-Carbon Anode Architecture for Stable High-Density Cycling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing lithium-ion batteries face challenges in achieving high energy density due to severe volume expansion of silicon-based negative electrode materials during cycling, which affects structural stability and cycle performance.
Innovation Solution
A negative electrode active material comprising a carbon core, porous carbon skeleton layer, and silicon-based particles, with a wave absorbing material distributed to control silicon distribution and limit volume expansion, combined with a carbon cladding layer for structural support.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If silicon-based particles are used as negative electrode active material, then energy density is improved, but volume expansion during cycling deteriorates structural stability
Solution Approach 1:
The patent employs a nested structure where silicon-based particles are embedded within a porous carbon skeleton layer, which itself is surrounded by a carbon cladding layer. This multi-layer nesting configuration allows silicon to expand during lithiation while the surrounding carbon structures provide mechanical constraints, preventing excessive volume expansion that would otherwise degrade structural stability and cycle performance.
Solution Approach 2:
The porous carbon skeleton layer provides a three-dimensional network with controlled porosity that accommodates silicon volume expansion. The porous structure allows silicon particles to expand into the void spaces during charging, reducing mechanical stress on the overall electrode structure and maintaining structural integrity over multiple cycles while preserving high energy density.
2Quantity of substance
If silicon-based particles are used to improve energy density, then capacity is improved, but conductivity deteriorates
Solution Approach 1:
The patent creates a composite material system combining silicon-based particles with carbon materials (porous carbon skeleton layer and carbon cladding layer). The carbon components provide excellent electrical conductivity pathways that compensate for silicon's lower conductivity, while the silicon particles contribute high capacity. This composite structure achieves both high capacity and reliable conductivity for improved electrochemical performance.
3Manufacturing precision
If wave absorbing material is added to control silicon distribution, then manufacturing precision is improved, but device complexity increases
Solution Approach 1:
The wave absorbing material acts as an intermediary component that enables precise control over silicon distribution during the coating process. By absorbing electromagnetic radiation, the wave absorbing material creates localized heating or field effects that guide silicon particle deposition into the porous carbon skeleton layer, achieving uniform and controlled distribution without requiring complex post-processing or multiple coating steps.
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 solution enhances energy density and cycle performance by effectively limiting volume expansion and improving conductivity, while maintaining structural stability through controlled silicon deposition and distribution.
Implementation Method 1
a wave absorbing material and silicon-based particles, where the wave absorbing material and the silicon-based particles are respectively and independently distributed in a region in which the carbon core is located and a region in which the porous carbon skeleton layer is located
Implementation Method 2
the silicon-based particles are distributed in the carbon core and the porous carbon skeleton layer, that is, the silicon-based particles are distributed in the outermost carbon cladding layer, so that volume expansion of silicon during a charge and discharge cycle can be effectively limited by using a porous structure of the porous carbon skeleton layer and the outermost carbon cladding layer
Data Source
AI summary
This application discloses a negative electrode active material and a preparation method therefor, a negative electrode plate, a battery, and an electrical device. The negative electrode active material includes a carbon core; a porous carbon skeleton layer, having an accommodation space inside, where the carbon core is located in the accommodation space; a carbon cladding layer, where the carbon cladding layer is cladded on at least a part of an outer surface of the porous carbon skeleton layer; and a wave absorbing material and silicon-based particles, where the wave absorbing material and the silicon-based particles are respectively and independently distributed in a region in which the carbon core is located and a region in which the porous carbon skeleton layer is located.