Amorphous SiOx Anode Material for High-Capacity Lithium Batteries
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium batteries using conventional anode materials face issues such as low capacity, volumetric expansion, and irreversible capacity, which hinder their practical application in portable electronic devices, and metallic lithium is unstable and prone to degradation.
Innovation Solution
A silicon oxide based composite anode active material with an amorphous structure, represented by SiOx (0<x<2), is developed, characterized by a specific silicon peak and binding energy range, prepared by sintering hydrogen silsesquioxane at 900-1300°C, which enhances lithium ion intercalation and deintercalation efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If metallic lithium is used as anode material to achieve high initial battery capacity, then battery capacity is improved, but lithium deposits form dendrites causing internal shorts and stability problems
Solution Approach 1:
The patent introduces a carbon coating layer as an intermediary between the silicon oxide particles and the electrolyte. This carbon layer prevents direct contact between lithium and oxygen atoms, eliminating the harmful reaction while still allowing lithium ion transport. The carbon acts as a mediator that enables the benefits of silicon oxide (high capacity) without its drawbacks (irreversible capacity loss).
Solution Approach 2:
The patent creates a composite anode material consisting of silicon oxide particles coated with carbon and combined with conductive carbon materials. This composite structure combines the high capacity advantage of silicon oxide with the stability and conductivity benefits of carbon, resolving the contradiction between capacity and reliability.
2Quantity of substance
If silicon oxide is used as anode material to achieve high capacity, then battery capacity is improved, but considerable irreversible capacities occur during initial charge-discharge cycling
Solution Approach 1:
The carbon coating layer serves as an intermediary that prevents direct reaction between lithium and oxygen atoms in the silicon oxide. This intermediary layer allows reversible lithium insertion/extraction while blocking the irreversible reaction pathway, thereby reducing irreversible capacity loss during initial cycling.
3Reliability
If carbonaceous materials are used as anode material to eliminate metallic lithium problems, then anode stability is improved, but battery capacity becomes low due to porosity
Solution Approach 1:
The patent creates a composite anode combining silicon oxide particles (providing high capacity through lithium alloying) with conductive carbon materials (providing stability and conductivity). This composite structure achieves both high capacity and stability, overcoming the limitations of pure carbonaceous anodes.
Solution Approach 2:
The patent changes the chemical composition and structure of the anode material from pure carbonaceous materials to silicon oxide-based composite materials. This parameter change enables higher capacity while maintaining stability through the carbon coating and conductive carbon matrix.
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 novel anode active material improves initial charge and discharge efficiency, exhibits excellent charge and discharge characteristics, and increases reversible capacity retention, addressing the limitations of conventional silicon oxide anodes.
Implementation Method 1
a technique of using a metal oxide exhibiting a relatively low volumetric expansion as an anode active material has been proposed
Implementation Method 2
High capacity electrodes using silicon oxides as the anode materials for secondary lithium ion batteries have also been proposed
Implementation Method 3
Carbonaceous anodes perform redox reactions such that lithium ions in the electrolytic solution intercalate/deintercalate in the carbonaceous material which has a crystal lattice structure during charge and discharge cycles
Implementation Method 4
use of an amorphous Sn-based oxide has been proposed which minimizes the Sn particle size and prevents agglomeration of Sn particles during charge and discharge cycles
Data Source
AI summary
Silicon oxide based composite anode active materials including amorphous silicon oxides are provided. In one embodiment, the amorphous silicon oxide is represented by SiOx (where 0<x<2), has a binding energy of about 103 to about 106 eV, a silicon peak with a full width at half maximum (FWHM) ranging from about 1.6 to about 2.4 as measured by X-ray photoelectron spectrometry, and an atomic percentage of silicon greater than or equal to about 10 as calculated from an area of the silicon peak. The anode active material is a composite anode active material obtained by sintering hydrogen silsesquioxane (HSQ). Anodes and lithium batteries including the anode active material exhibit improved charge and discharge characteristics.