Graphite Anode Compound Layer for Stable SEI and Electrolyte Wetting
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Solution Overview
Problem
Conventional graphite anode materials in lithium ion batteries suffer from poor compatibility with electrolytes, leading to unstable Solid Electrolyte Interface (SEI) films, low initial coulombic efficiency, and continuous capacity decay due to irreversible reactions with electrolyte components.
Innovation Solution
A synergistic combination of a carbonaceous and non-carbonaceous material in the compound layer on the graphite core, formed through a polymerization and carbonization process, enhances interface stability and reduces specific surface area, improving electrolyte wettability and lithium ion transmission efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If coating layer is applied to reduce specific surface area, then electrolyte wettability is improved, but interface side reactions still occur
Solution Approach 1:
The coating layer uses a composite formulation with amorphous carbon providing good electrolyte wettability and reduced specific surface area, while inorganic components like Li2SiO3 and SiO2 provide chemical stability to prevent interface side reactions. The synergistic combination of these materials simultaneously achieves both desired properties.
Solution Approach 2:
The coating layer acts as an intermediary between the graphite anode and the electrolyte. The amorphous carbon component facilitates electrolyte contact and wetting, while the inorganic compounds serve as a protective mediator that prevents harmful side reactions at the interface, allowing beneficial reactions while blocking detrimental ones.
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 anode material exhibits improved high-temperature storage performance, electrode processing performance, and reduced interface side reactions, resulting in enhanced reversible capacity and rate performance.
Implementation Method 1
performing a polymerization reaction on a first mixed solution containing the graphite and the organic molecular monomer to obtain a first precursor, wherein a polymer formed through polymerization of the organic molecular monomer is compounded on surfaces of graphite particles to form the polymer layer
Implementation Method 2
inorganic ions are formed through hydrolysis of the inorganic salt in the second mixed solution, and through a grafting reaction between the highly-reactive functional group in the polymer and the inorganic ions, the inorganic ions are grafted and introduced into the polymer layer
Implementation Method 3
a carbonization treatment is performed on the second precursor, through the carbonization treatment, in situ cracking occurs in the organic molecules in the polymer layer to obtain the carbonaceous material, and the inorganic ions are in situ converted into the non-carbonaceous material at the same time
Data Source
AI summary
Provided are an anode material and a preparation method thereof, and a lithium ion battery. The anode material includes a core and a compound layer located on at least partial surface of the core; and the core includes graphite, and the compound layer includes a carbonaceous material and a non-carbonaceous material.