Silicon Clathrate Anode Material With Fine Voids for Low Swelling
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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 electronic vehicles and hybrid vehicles.
Innovation Solution
The development of a silicon clathrate II type crystal phase active material with voids of fine pore diameter 100 nm or less, which reduces volume variation by incorporating Li ions within the material's structure, thereby minimizing the need for high confining pressures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If Si is used as an active material to achieve high energy condensation, then the energy storage capacity is improved, but the volume variation during charge/discharge increases
Solution Approach 1:
The patent introduces a porous structure with voids inside the Si particles, where the void amount is specifically controlled to be 0.03 cc/g or more and 0.15 cc/g or less. This porous structure allows the Si to expand and contract during charge/discharge without generating excessive stress, thereby reducing volume variation while maintaining high energy storage capacity.
Solution Approach 2:
The patent creates a composite structure by combining Si particles with a specific porous matrix. The composite consists of Si particles dispersed in a porous material framework, where the porous matrix provides structural support and accommodates volume changes, enabling both high capacity and stable volume during cycling.
2Volume of moving object
If high confining pressure is applied to suppress volume variation, then the volume stability is improved, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The porous structure acts as a self-confining framework that inherently restricts Si particle expansion during lithiation. The rigid porous matrix provides internal mechanical support, eliminating the need for external confining pressure systems or complex mechanical constraints, thereby simplifying the overall device design while maintaining volume stability.
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 approach results in a battery with reduced volume variation during charge/discharge, enhancing durability and energy storage efficiency while allowing for a smaller confining jig, thus improving battery performance.
Implementation Method 1
reduces volume variation by incorporating Li ions within the material's structure
Data Source
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.