Particulate Silicon Oxide Negative Electrode for Lithium Ion Battery
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Solution Overview
Problem
Silicon oxide-based active materials for negative electrodes in nonaqueous secondary batteries are expensive and have inferior cycle performance, limiting their effectiveness in applications beyond portable electronics.
Innovation Solution
Particulate silicon oxide with controlled metal content (Cu, Fe, Al) and specific surface area, prepared by heating a silicon oxide-providing feed material in an inert gas, is used as the negative electrode material, enhancing cycle performance and reducing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If silicon oxide is used as negative electrode material to achieve high battery capacity, then battery capacity is improved by a factor of 5 or 6 compared to carbon, but cycle performance deteriorates and manufacturing cost increases
Solution Approach 1:
The patent applies parameter changes by precisely controlling the metal content composition in silicon oxide particles. Specifically, it limits Cu content to 100-20,000 ppm, Fe content to 20-1,000 ppm, and Al content to up to 1,000 ppm. This compositional parameter optimization resolves the contradiction by maintaining high battery capacity while significantly improving cycle performance, as the controlled metal content reduces volume expansion and enhances structural stability during charge-discharge cycles.
Solution Approach 2:
The patent utilizes composite materials by creating silicon oxide particles with controlled metal content that form a composite structure. The silicon oxide matrix is combined with trace amounts of specific metals (Cu, Fe, Al) within defined concentration ranges, creating a composite material that leverages the high capacity of silicon oxide while the controlled metal content provides structural support and reduces degradation, thereby improving cycle performance.
2Quantity of substance
If silicon oxide is used as negative electrode material to achieve high battery capacity, then battery capacity is improved by a factor of 5 or 6 compared to carbon, but manufacturing cost increases
Solution Approach 1:
The patent applies parameter changes by optimizing the metal content ranges in silicon oxide particles (Cu: 100-20,000 ppm, Fe: 20-1,000 ppm, Al: up to 1,000 ppm). This parameter optimization enables cost-effective manufacturing by allowing the use of naturally occurring trace metals rather than requiring expensive ultra-pure silicon oxide, while still achieving the desired high battery capacity and improved cycle performance.
Solution Approach 2:
The patent employs the principle of using inexpensive materials with controlled impurities. Instead of requiring expensive high-purity silicon oxide, it utilizes silicon oxide particles containing trace amounts of common metals (Cu, Fe, Al) within specific ranges. These trace metals, which would normally be considered impurities to be removed at great cost, are instead controlled to provide beneficial effects, significantly reducing manufacturing cost while maintaining high battery capacity.
3Quantity of substance
If conventional silicon oxide particles are used, then high battery capacity is achieved, but volume expansion occurs and cycle performance deteriorates
Solution Approach 1:
The patent applies parameter changes by precisely controlling the metal content composition (Cu: 100-20,000 ppm, Fe: 20-1,000 ppm, Al: up to 1,000 ppm) in silicon oxide particles. This compositional parameter control resolves the contradiction by reducing volume expansion during lithium insertion/extraction cycles. The controlled metal content creates a more stable crystal structure that accommodates volume changes better, maintaining high battery capacity while improving compositional stability and reducing expansion.
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 particulate silicon oxide with optimized metal content and surface area improves the cycle performance and capacity of nonaqueous secondary batteries, making them suitable for automotive applications while reducing manufacturing costs.
Implementation Method 1
heating a silicon oxide-providing feed material in an inert gas to generate a SiO gas
Implementation Method 2
cooling the gas to a temperature in the range of 500 to 1,100° C. for deposition
Data Source
AI summary
Particulate silicon oxide having a Cu content of 100-20,000 ppm, an Fe content of 20-1,000 ppm, an Al content of up to 1,000 ppm, an average particle size of 0.1-30 μm, and a BET specific surface area of 0.5-30 m2/g is used as negative electrode material in constructing a nonaqueous electrolyte secondary battery. The secondary battery is improved in cycle performance while maintaining the high battery capacity and low volume expansion of silicon oxide.