Coated Lithium Manganese Active Material for Interface Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing active materials in batteries suffer from performance deterioration due to manganese elution and resistance layer formation at the interface with electrolytes, which hinders lithium ion transfer and overall battery performance.
Innovation Solution
A coating portion containing elements like Ti, Zr, Ta, or Al and oxygen is applied to the surface of a core portion comprising lithium, manganese, and oxygen, with a specific thickness and coverage ratio to prevent manganese elution and resistance layer formation, ensuring smooth lithium ion transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a coating portion is applied to the surface of the core portion to prevent manganese elution and resistance layer formation, then battery performance and reliability are improved, but the device complexity and manufacturing process complexity increase
Solution Approach 1:
A coating portion containing element A and oxygen is formed in advance on the surface of the core portion before battery assembly. This preliminary coating prevents manganese elution and resistance layer formation during subsequent battery operation, improving reliability without requiring complex operational controls.
Solution Approach 2:
The active material is structured as a composite with a core portion containing Li, Mn, and O, and a coating portion containing element A (such as Al, Ti, Zr, Ta, Nb) and oxygen. This composite structure combines the high capacity of the core material with the protective and conductive properties of the coating, resolving the contradiction between performance and complexity.
2Reliability
If the coating portion thickness is increased to improve protection against manganese elution, then reliability improves, but the specific surface area decreases and manufacturing precision requirements increase
Solution Approach 1:
The coating thickness is precisely controlled within the range of 0.1-10 nm, and the amount of element A is optimized to achieve W/(S×T) > 0 and ≤ 15% by mass/(cm³/g). These parameter optimizations provide sufficient protection against manganese elution while maintaining high specific surface area and avoiding excessive manufacturing difficulty.
Solution Approach 2:
The coating portion is applied as an ultra-thin layer with non-uniform distribution optimized for local needs. The coating provides targeted protection where manganese elution is most problematic while minimizing overall thickness to preserve specific surface area and reduce manufacturing precision requirements.
3Reliability
If element A is added to the coating portion to prevent resistance layer formation, then electrical conductivity is improved, but the amount of substance increases and cost may rise
Solution Approach 1:
The concentration of element A in the coating is precisely controlled to optimize electrical conductivity. By adjusting the amount of element A and the coating thickness to achieve W/(S×T) > 0 and ≤ 15% by mass/(cm³/g), sufficient electrical conductivity is achieved with minimal amounts of expensive elements.
Solution Approach 2:
Element A in the coating portion acts as an intermediary between the core portion and the electrolyte. It prevents direct harmful interactions while maintaining electrical conductivity, allowing the use of smaller amounts of element A compared to bulk modifications.
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 coating effectively suppresses performance deterioration and enhances battery performance by preventing manganese elution and interface resistance, maintaining the core portion's functionality without increasing resistance.
Implementation Method 1
a coating portion arranged on a surface of the core portion, wherein the coating portion contains an element A (A is at least one selected from the group consisting of Ti, Zr, Ta, Nb, and Al) and elemental oxygen (O)
Implementation Method 2
ensuring smooth lithium ion transfer
Implementation Method 3
forming a coating portion containing an element A (A is at least one selected from the group consisting of Ti, Zr, Ta, Nb, and Al) and elemental oxygen (O) through atomic layer deposition on the surface of the core portion
Data Source
AI summary
An active material includes a core portion, and a coating portion arranged on a surface of the core portion. The core portion contains elemental lithium (Li), elemental manganese (Mn), and elemental oxygen (O). The coating portion contains an element A (A is at least one selected from the group consisting of Ti, Zr, Ta, Nb, and Al) and elemental oxygen (O). W/(T×S) is more than 0 and 15% by mass/(cm3/g) or less, wherein T (nm) represents an average thickness of the coating portion, S (m2/g) represents a specific surface area of the active material, and W (% by mass) represents an amount of element A contained in the coating portion.