Silicon-Carbon Electrode Structure for High-Density Electrochemical Cells
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrochemical cells face challenges in achieving a balance between size reduction and maintaining high energy density while minimizing electrical resistance.
Innovation Solution
The electrochemical cell design incorporates a first electrode with a silicon layer and a carbon material layer on its surface, and a second carbon material layer continuous with the first, integrated with a separator and a casing, to enhance energy density and reduce electrical resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a silicon layer is used as the electrode active material to increase energy density, then the energy density is improved, but the electrical resistance increases and the cell size increases
Solution Approach 1:
The patent uses a composite structure combining silicon layer and carbon material layer on the current collector. The silicon layer provides high capacity for lithium insertion/extraction to achieve high energy density, while the carbon material layer provides conductivity to reduce electrical resistance. This composite material approach resolves the contradiction between high energy density and low electrical resistance.
2Quantity of substance
If a silicon layer is used as the electrode active material to increase energy density, then the energy density is improved, but the cell size increases
Solution Approach 1:
The electrode active material layer is segmented into two distinct portions: a first portion with silicon layer for high energy density and a second portion with carbon material layer for conductivity. This segmentation allows optimization of different regions for different functions, achieving high energy density while controlling cell size through efficient space utilization.
3Volume of moving object
If the electrode active material layer is made thinner to reduce cell size, then the cell size is reduced, but the energy density decreases
Solution Approach 1:
Different regions of the electrode active material layer have different compositions optimized for their specific functions. The first portion contains silicon layer optimized for high capacity and energy density, while the second portion contains carbon material optimized for conductivity. This local quality differentiation allows the layer to be thin enough to reduce cell size while maintaining high energy density through the high-capacity silicon region.
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
This configuration allows for a smaller electrochemical cell with increased energy density and reduced electrical resistance, as demonstrated by higher energy density and comparable or improved electrical resistance compared to comparative examples.
Implementation Method 1
an electrochemical cell includes a first electrode including a first current collector and a first electrode active material layer, a second electrode including a second current collector and a second electrode active material layer
Data Source
AI summary
An electrochemical cell includes an electricity generator, a casing, and a terminal. The electricity generator includes a negative electrode, a positive electrode, and a separator between the negative electrode and the positive electrode. The negative electrode includes a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer includes a first portion including a silicon layer on a surface of the negative electrode current collector and a first carbon material layer on a surface of the silicon layer, and a second portion including a second carbon material layer on the surface of the negative electrode current collector and continuous with the first carbon material layer.