Li2SiO3-Coated Cathode Material for Lower Interfacial Resistance
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Solution Overview
Problem
The development of cost-effective and stable coating materials for sulfide-based all-solid-state batteries is hindered by the rarity and high cost of niobium-based materials, which limits the scalability and performance of these batteries due to high interfacial resistance between the electrolyte and active materials.
Innovation Solution
A cathode active material composition using colloidal silica as a coating precursor, combined with a lithium source and a solvent, forms a Li2SiO3 coating layer on the surface of active material particles, enhancing dispersion and reducing interfacial resistance, while being more economical and safer to handle than traditional niobium-based methods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If niobium-based coating materials are used to reduce interfacial resistance, then the battery performance is improved, but the manufacturing cost increases significantly due to the rarity and high cost of niobium
Solution Approach 1:
The patent replaces expensive niobium-based coating materials with inexpensive colloidal silica and lithium hydroxide materials that can be easily obtained. This substitution dramatically reduces raw material costs while maintaining the functional performance of reducing interfacial resistance between the sulfide-based solid electrolyte and oxide-based cathode active material.
Solution Approach 2:
The patent changes the chemical composition parameters of the coating layer from niobium-based compounds to lithium silicate (Li2SiO3) formed from colloidal silica and lithium hydroxide. This parameter change in material composition achieves similar interfacial resistance reduction effects while using abundant, low-cost materials.
2Reliability
If conventional coating materials are used, then interfacial resistance is reduced, but the handling safety decreases due to the reactivity and cost of materials like ethoxide
Solution Approach 1:
The patent replaces reactive and expensive ethoxide-based materials with stable, safe, and inexpensive colloidal silica and lithium hydroxide. These materials are much safer to handle, store, and process, eliminating the hazards associated with reactive ethoxides while maintaining the coating's functional performance.
Solution Approach 2:
The coating system uses colloidal silica and lithium hydroxide that can be easily mixed in aqueous or alcoholic solutions, forming a stable coating precursor that self-assembles on the cathode material surface during drying. This eliminates the need for complex handling procedures required for reactive ethoxide materials.
3Device complexity
If powder-based cathode materials are used, then the battery structure is simple, but the particle dispersion is poor leading to non-uniform electrode composition
Solution Approach 1:
The patent introduces a liquid precursor solution containing colloidal silica and lithium hydroxide as an intermediary medium. This liquid carrier enables uniform distribution of coating materials around cathode particles, ensuring consistent composition and properties throughout the electrode while maintaining the simplicity of the overall battery structure.
Solution Approach 2:
The patent forms a thin film coating layer of lithium silicate on the cathode particle surfaces. This thin film uniformly covers the particles, improving dispersion and compositional uniformity without adding significant structural complexity or thickness that would interfere with battery performance.
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
This approach improves the dispersion and stability of the cathode active material, leading to enhanced lithium ion conductivity, reduced surface resistance, and increased battery lifespan, making the process more cost-effective and suitable for mass production.
Implementation Method 1
forms a Li2SiO3 coating layer on the surface of active material particles
Implementation Method 2
exhibiting lithium ion conductivity
Implementation Method 3
enhancing dispersion in a sulfide-based all-solid-state battery
Data Source
AI summary
A cathode active material for an all-solid-state battery including colloidal silica, a cathode active material, and a manufacturing method thereof are disclosed. It may be possible to achieve an enhancement in dispersion in a sulfide-based all-solid-state battery by controlling powder properties while reducing interfacial resistance between an electrolyte and a cathode active material of the sulfide-based all-solid-state battery.