SiOx Negative Electrode Active Material for Lithium-Ion Battery
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Solution Overview
Problem
Lithium-ion rechargeable batteries using conventional negative active materials face issues with low initial efficiency and high irreversible capacity, leading to economically infeasible battery capacity increases due to excessive positive electrode material requirements.
Innovation Solution
A negative electrode active material for non-aqueous electrolyte rechargeable batteries is developed, comprising SiOx with an O/Si molar ratio of 0.5 to 1.6, where XPS peaks for Si—O binding energy are within specific ranges, and a carbon-based material is coated on the surface to improve initial efficiency and cycle characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional carbon-based materials are used as negative electrode active material, then the battery structure is stable, but the energy density and capacity are limited
Solution Approach 1:
The patent changes the chemical composition parameters of the negative electrode active material by using SiOx with specific O/Si molar ratios (0.5-1.6) and controlling the crystalline silicon content (1-50 wt%), thereby achieving higher lithium ion insertion/extraction capacity while maintaining structural stability during cycling
Solution Approach 2:
The patent employs a composite material structure consisting of crystalline silicon dispersed in silicon dioxide matrix, where the silicon provides high capacity and the二氧化硅 provides structural stability, creating a synergistic effect that resolves the contradiction between capacity and cycle life
2Quantity of substance
If SiOx with high silicon content is used to increase capacity, then energy density improves, but expansion and contraction during lithium ion adsorption/release cause insufficient retention of discharge capacity
Solution Approach 1:
The patent optimizes the O/Si molar ratio parameter within 0.5-1.6 and controls crystalline silicon content at 1-50 wt%, finding the optimal balance between capacity and stability. This parameter optimization ensures sufficient lithium ion insertion sites while maintaining structural integrity during cycling
Solution Approach 2:
The silicon dioxide matrix acts as a protective cushion that pre-comprises the expansion stress of crystalline silicon during lithium ion insertion, preventing structural collapse and maintaining discharge capacity retention throughout cycling
3Reliability
If carbon film is formed on surface of silicon composite to improve structure, then cycle characteristics improve, but initial efficiency is limited
Solution Approach 1:
The patent changes the surface composition by forming a carbon-based material coating on SiOx particles, which improves electrical conductivity and initial reaction efficiency while the underlying SiOx structure provides long-term cycling stability, resolving the contradiction between initial efficiency and cycle life
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 solution enhances the initial efficiency and cycle characteristics of lithium-ion rechargeable batteries by suppressing irreversible reactions and optimizing the structure and composition of the negative electrode active material, resulting in improved battery performance and reduced material requirements.
Implementation Method 1
forming SiOx by performing a first heat treatment on a silicon oxide powder represented by SiOx (0.5≦x≦1.6) in an inert atmosphere or a reducing atmosphere at a temperature of 800° C. to 1400° C. for 30 minutes to 8 hours
Implementation Method 2
forming a carbon-based material on a surface of the SiOx by performing a second heat treatment on the SiOx in a carbon-containing gas atmosphere or a vapor atmosphere at a temperature of 600° C. to 1200° C. for 30 minutes to 8 hours
Data Source
AI summary
A camera module is disclosed, the camera module including a PCB (Printed Circuit Board), a base arranged at an upper surface of the PCB, a holder member arranged at an upper surface of the base and formed with a plurality of magnet reception portions, a surface of which facing the base is opened, and a plurality of magnets coupled to the magnet reception portions, wherein the base is formed with a protrusion configured to support a bottom surface of the magnet by being protrusively formed at a position corresponding to an opening of the magnet reception portions.