Silicon Clathrate Anode Material With Fine Voids for Volume Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The large volume variation of silicon (Si) during charge/discharge in batteries limits the durability and efficiency of energy storage, particularly in high-energy applications like electric vehicles.
Innovation Solution
A silicon clathrate II type crystal phase with voids of fine pore diameter 100 nm or less is used as an active material, which reduces volume variation by incorporating Li ions within the crystal structure, thereby minimizing the need for high confining pressures and enhancing durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If Si is used as an active material to achieve high energy condensation, then the battery energy density is improved, but the volume variation during charge/discharge increases
Solution Approach 1:
The patent embeds Si particles within a porous carbon structure, creating a nested configuration where the Si is contained within the carbon matrix. This nesting approach allows the Si to expand and contract during charge/discharge while being constrained by the carbon framework, thereby reducing overall volume variation while maintaining high energy density
Solution Approach 2:
The patent utilizes porous carbon as the active material structure, which provides void spaces that can accommodate Si expansion during lithiation. The porous structure allows volume changes to occur within the pores rather than causing external expansion, thus maintaining structural stability while enabling high energy storage capacity
2Use of energy by moving object
If Si is used as an active material to achieve high energy condensation, then the battery energy density is improved, but the durability decreases
Solution Approach 1:
The nested structure of Si within porous carbon provides mechanical protection to the Si particles during repeated charge/discharge cycles. The carbon framework acts as a protective shell that prevents particle aggregation and structural degradation, thereby improving durability while maintaining high energy density
Solution Approach 2:
The patent creates a composite material system combining Si and porous carbon, where each component compensates for the other's weaknesses. The Si provides high capacity while the porous carbon provides structural stability and conductivity, resulting in a composite that delivers both high energy density and improved durability
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 use of silicon clathrate II type crystal phase with embedded voids results in a battery anode layer with reduced volume variation during charge/discharge, improving energy storage efficiency and durability by suppressing the expansion caused by Li ion intercalation.
Implementation Method 1
incorporating Li ions within the crystal structure
Data Source
Figure 1A~2
Figure 3~4
Figure 5
AI summary
A main object of the present disclosure is to provide an active material wherein a volume variation due to charge/discharge is small. The present disclosure achieves the object by providing an active material comprising a silicon clathrate II type crystal phase, including a void inside a primary particle, and a void amount of the void with a fine pore diameter of 100 nm or less is 0.05 cc/g or more and 0.15 cc/g or less.