Coated Mn-Rich Cathode Materials for High-Voltage Li-Ion Cycling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing lithium-ion batteries face challenges in achieving high storage performance and cycle performance, especially under high-voltage conditions.
Innovation Solution
A secondary battery design featuring a positive active material with a core and a coating, where the manganese content in the core is greater than or equal to 25%, and the coating contains oxides, hydroxides, or oxyacid salts of elements like Al, B, or P. The electrolyte solution includes fluorinated solvents, and specific ratios and coefficients are maintained to enhance stability and performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If high-voltage conditions are used to increase energy density, then power output is improved, but storage performance and cycle performance deteriorate
Solution Approach 1:
A coating layer containing oxide, hydroxide, or oxyacid salt of Al, B, or P is introduced as an intermediary between the positive active material core and the electrolyte solution. This coating layer mediates the interaction at the interface, reducing direct contact between the high-voltage positive electrode and the electrolyte, thereby suppressing side reactions and improving storage and cycle performance while maintaining high-voltage operation
Solution Approach 2:
The patent changes the chemical composition parameters of the coating layer by selecting specific elements (Al, B, P) and their compounds (oxide, hydroxide, oxyacid salt). This parameter change optimizes the interface stability between the positive electrode and electrolyte, enabling high-voltage operation with improved reliability
2Device complexity
If conventional positive active materials are used to simplify structure, then manufacturing cost is reduced, but manganese ion dissolution increases leading to poor interface stability
Solution Approach 1:
The positive active material is designed as a composite structure with a core (containing Mn with ≥25% mass content) and a coating layer (containing oxide, hydroxide, or oxyacid salt of Al, B, or P). This composite structure combines the high capacity of manganese-based materials with the protective properties of the coating, reducing manganese ion dissolution while maintaining structural simplicity
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 proposed battery design significantly improves the stability of the cathode electrolyte interface, reduces side reactions, and enhances storage performance and cycle performance under high-voltage conditions.
Implementation Method 1
The coating overlays a surface of the core and contains one or more of an oxide, hydroxide, or oxyacid salt of element X
Implementation Method 2
The electrolyte solution contains a first solvent. The first solvent is one or more selected from a fluorocarbonate ester, a fluorocarboxylate ester, a fluorosulfone, a fluoroether, or a fluorobenzene
Data Source
AI summary
A secondary battery is disclosed. The secondary battery includes a positive electrode plate, a negative electrode plate, a separator, and an electrolyte solution. The positive electrode plate includes a positive active material. The positive active material includes a core and a coating. A manganese content of the core is greater than or equal to 25% based on a mass of the core. The coating overlays a surface of the core and contains one or more of an oxide, hydroxide, or oxyacid salt of element X. The element X is one or more selected from Al, B, or P. A mass ratio of the coating to the core is 1:(5 to 100), and optionally 1:(16 to 100). The electrolyte solution contains a first solvent. The first solvent is one or more selected from a fluorocarbonate ester, a fluorocarboxylate ester, a fluorosulfone, a fluoroether, or a fluorobenzene.