Silicon Oxide Negative Electrode with Cobalt for Battery Cycle Life
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Solution Overview
Problem
Silicon oxide materials used as negative electrodes in nonaqueous electrolyte secondary batteries face challenges of high cost and inferior cycle performance compared to carbon-based active materials, limiting their application in portable and automotive sectors.
Innovation Solution
A silicon oxide material with a controlled cobalt content of 2 to 200 ppm, optimized particle size, and specific surface area is used as a negative electrode active material, prepared through a method involving heating silicon oxide gas-providing raw materials under reduced pressure to generate SiO gas and precipitate the material, enhancing battery capacity and cycle performance.
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 increases by a factor of 5 or 6 compared to carbon, but cycle performance becomes insufficient
Solution Approach 1:
The patent applies parameter changes by precisely controlling the cobalt content in silicon oxide to within 2 to 200 ppm. This specific concentration range of cobalt impurity acts as a catalyst to improve cycle performance while preserving the high capacity characteristics of silicon oxide. The transformation involves changing the chemical composition parameters of the silicon oxide material to achieve both high capacity and improved reliability.
2Quantity of substance
If silicon oxide is used as negative electrode material to achieve high battery capacity, then battery capacity increases by a factor of 5 or 6 compared to carbon, but manufacturing cost increases
Solution Approach 1:
The patent utilizes parameter changes by optimizing the cobalt content range (2-200 ppm) in silicon oxide material. This specific compositional parameter allows the material to achieve high battery capacity while becoming cost-effective for manufacturing. The controlled impurity level transforms the material into an economically viable option for large-scale production.
Solution Approach 2:
The patent employs the principle of using inexpensive materials with controlled impurities. By accepting and optimizing for small amounts of cobalt impurity (2-200 ppm) rather than requiring ultra-pure silicon oxide, the manufacturing cost is significantly reduced while still achieving the desired high battery capacity performance.
3Volume of stationary object
If silicon oxide is used as negative electrode material, then volume expansion is reduced compared to pure silicon, but cycle performance remains inferior to carbon-based materials
Solution Approach 1:
The patent applies parameter changes by introducing and controlling the cobalt content parameter in silicon oxide. The cobalt impurity at concentrations of 2-200 ppm acts as a catalyst that enhances cycle performance. This compositional modification allows the material to maintain low volume expansion characteristics while achieving improved reliability and cycle 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
The silicon oxide material achieves improved cycle performance and cost-effectiveness, suitable for both portable and automotive applications, while maintaining high battery capacity and low volume expansion, facilitating industrial-scale manufacturing.
Implementation Method 1
heating silicon oxide gas-providing raw materials under reduced pressure to generate SiO gas
Implementation Method 2
cool the SiO gas to a temperature in the range of 500 to 1,100° C. for precipitation
Data Source
AI summary
A silicon oxide material having a cobalt content of 2-200 ppm is provided. A negative electrode is formed using the silicon oxide material as active material. A nonaqueous electrolyte secondary battery constructed using the negative electrode exhibits improved cycle performance while maintaining the high battery capacity and low volume expansion of silicon oxide.