Layered Silicon Anode Structure for Low-Resistance Cycle Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional secondary batteries face challenges in achieving high capacity and good cycle performance while maintaining low resistance, particularly in applications requiring high energy density and efficient lithium-ion transmission.
Innovation Solution
A secondary battery design incorporating a negative electrode plate with a silicon-based material and a porous material, where the porous material is strategically layered to enhance lithium-ion transmission and reduce cycle expansion, thereby improving capacity, cycle performance, and resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional secondary battery designs are used, then manufacturing simplicity is maintained, but capacity and cycle performance cannot be improved while keeping resistance low
Solution Approach 1:
The negative electrode active material layer is segmented into multiple layers with different compositions and functions. The first layer contains silicon-based material for high capacity, while the second layer contains porous material for structural stability and lithium-ion transmission. This segmentation allows each layer to specialize in specific functions, resolving the contradiction between achieving high capacity and maintaining good cycle performance without excessive overall complexity.
Solution Approach 2:
The patent employs composite material structure by combining silicon-based material with porous material in a layered configuration. The silicon-based material provides high theoretical capacity, while the porous material (such as porous carbon, metal, or ceramic) provides structural framework and facilitates lithium-ion diffusion. This composite approach enables the battery to achieve both high capacity and good cycle performance simultaneously.
2Quantity of substance
If silicon-based material is used to increase capacity, then energy density is improved, but cycle expansion rate increases and cycle performance deteriorates
Solution Approach 1:
The patent introduces porous material (porous carbon, porous metal, or porous ceramic) as the second layer in the negative electrode. This porous structure serves multiple functions: it provides a stable framework that accommodates silicon expansion, maintains structural integrity during cycling, and facilitates lithium-ion diffusion through its porous network. The porosity allows the structure to absorb expansion stresses while maintaining overall stability, thus enabling high capacity from silicon while controlling cycle expansion rate.
Solution Approach 2:
The structure implements a nested configuration where the silicon-based material layer is positioned within the supportive framework of the porous material layer. The first layer (silicon-based) is nested against the second layer (porous material), allowing the porous structure to contain and stabilize the silicon during volume changes. This nested arrangement enables the high-capacity silicon to function while being protected by the stable porous framework.
3Object-generated harmful factors
If porous material is added to improve lithium-ion transmission, then resistance is reduced, but electrode structure complexity increases
Solution Approach 1:
The patent applies local quality by positioning the porous material specifically in the second layer of the negative electrode, where it is most needed for facilitating lithium-ion transmission and providing structural stability. The first layer retains silicon-based material for high capacity, while the second layer introduces porous material locally to address resistance issues. This localized application of porous material reduces overall complexity compared to using porous material throughout the entire electrode structure.
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 battery achieves a high capacity, good cycle performance, and low resistance through the optimized use of silicon-based and porous materials, specifically porous carbon, metal, or ceramic, which facilitates efficient lithium-ion transmission and minimizes cycle expansion.
Implementation Method 1
the porous material is strategically layered to enhance lithium-ion transmission
Implementation Method 2
the silicon-containing negative electrode plate has a relatively low cycle expansion rate
Data Source
AI summary
The present disclosure provides a secondary battery including a negative electrode plate, and the negative electrode plate includes: a negative electrode current collector, a first negative electrode active material layer, and a second negative electrode active material layer. The first negative electrode active material layer is arranged on at least one surface of the negative electrode current collector, and the first negative electrode active material layer includes a silicon-based material and a porous material; and the second negative electrode active material layer is arranged on a surface of the first negative electrode active material layer away from the negative electrode current collector.