Halide-Coated Cathode Material for Stable Solid-State Battery Interfaces
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Solution Overview
Problem
The interface instability between high-voltage lithium-rich manganese-based positive electrode materials and sulfide solid electrolytes in lithium-ion batteries leads to poor cycle performance, and conventional solutions require specialized equipment and are costly.
Innovation Solution
A positive electrode material is developed, comprising a lithium-rich manganese-based active material coated with a halide solid electrolyte, specifically Li2+m Zr1-m Fe m Cl 6-x-y Br x I y, which enhances interface stability and suppresses side reactions under high voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a stable oxide coating layer is applied to the surface of high-voltage lithium-rich manganese-based positive electrode material to alleviate interface instability with sulfide solid electrolyte, then the interface stability is improved, but the production cost increases and specialized equipment is required
Solution Approach 1:
The patent introduces a halide solid electrolyte coating layer as an intermediary between the lithium-rich manganese-based positive electrode material and the sulfide solid electrolyte. This intermediary layer effectively reduces interface instability and suppresses side reactions without requiring specialized coating equipment or incurring high production costs, thereby resolving the contradiction between interface stability and manufacturing ease.
2Reliability
If conventional oxide coating methods are used to protect the positive electrode material, then the interface stability is improved, but the device complexity and equipment requirements increase
Solution Approach 1:
The halide solid electrolyte coating serves as a mediator that can be applied using conventional coating techniques without specialized equipment. This intermediary layer provides the necessary interface stability while avoiding the complexity and equipment requirements of conventional oxide coating methods.
3Ease of manufacture
If the positive electrode material is used without coating to maintain simplicity, then the manufacturing process is simple, but side reactions occur under high voltage leading to poor cycle performance
Solution Approach 1:
The patent employs a thin halide solid electrolyte coating layer that can be applied through simple processes. This coating acts as a protective barrier that prevents side reactions under high voltage, thereby improving cycle performance without significantly complicating the manufacturing process or requiring expensive equipment.
4Reliability
If a coating layer is applied to suppress side reactions, then the cycle performance is improved, but the manufacturing cost increases
Solution Approach 1:
The halide solid electrolyte coating is applied in a thin layer using cost-effective methods, providing sufficient protection to suppress side reactions and improve cycle performance without significantly increasing manufacturing costs. The coating material and application process are optimized to maintain cost-effectiveness.
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 halide solid electrolyte coating improves the stability and cycle performance of lithium-ion batteries by enhancing lithium ion conductivity, suppressing side reactions, and maintaining high voltage resistance, while reducing production costs.
Implementation Method 1
the halide solid electrolyte has good compatibility with high-voltage lithium-rich manganese-based positive electrode material to enhance the lithium ion conductivity of the positive electrode material and effectively improve ion transmission dynamics
Implementation Method 2
enhance the lithium ion conductivity of the positive electrode material and effectively improve ion transmission dynamics
Implementation Method 3
The reversible redox ability of oxygen during the cycle may be improved, thereby inhibiting the dissolution of transition metals and the release of oxygen from the positive electrode, thus improving initial Coulombic efficiency and cycle life
Data Source
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AI summary
The invention provides a positive electrode material and a preparation method and an application thereof. The positive electrode material at least includes: a positive electrode active material; and a coating layer coating the positive electrode active material, the coating layer including a halide solid electrolyte; wherein: the positive electrode active material includes nLi2MnO3•(1-n)LiMnaCobNicO2, and 0.2≤n≤0.5, a+b+c=1; a chemical formula of the halide solid electrolyte is Li2+mZr1-mFemCl6-x-yBrxIy, and 0<m≤0.5; x=0 to 6, y=0 to 6, x+y≤6. The invention provides a positive electrode material and a preparation method and an application thereof that may improve the interface stability between a positive electrode sheet and a solid electrolyte and improve a stability and a cycle performance of a lithium-ion battery.