LMNO Composite Cathode With In-Situ LATP Coating for High-Voltage Cycling
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Solution Overview
Problem
Lithium manganese nickel oxide (LMNO) cathode materials face degradation and performance issues due to decomposition under high voltage, leading to capacity decline, rate performance, and cycle life problems, particularly when coated with solid electrolytes using conventional complex processes.
Innovation Solution
A dry mechanical mixing method is employed to mix nickel-manganese compounds with lithium titanium aluminum phosphate (LATP) solid electrolyte material, forming a composite cathode material with a core of LiNi0.5Mn1.5O4 and a LATP coating layer, optimizing the weight percentage of LATP to 0.2-1.0 wt.% to enhance performance and reduce manufacturing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional coating methods are used to coat solid electrolyte on LMNO, then the surface microstructure is improved and conductivity is enhanced, but the manufacturing process becomes complicated and performance degrades during coating
Solution Approach 1:
The patent combines the solid electrolyte coating process with the cathode material synthesis process into a single sintering step. The solid electrolyte precursor and cathode precursor are mixed before sintering, allowing the coating layer to form simultaneously with the cathode material, thereby eliminating separate coating steps and reducing process complexity
Solution Approach 2:
The patent applies preliminary action by mixing the solid electrolyte precursor with the cathode precursor before the sintering process. This pre-mixing ensures that the solid electrolyte is already positioned on the cathode material surface before sintering, allowing the coating to form in-situ during the synthesis process rather than requiring post-synthesis coating steps
2Duration of action of moving object
If solid electrolyte coating is applied to improve rate performance, then cycle life is enhanced, but manufacturing cost increases due to additional processing steps
Solution Approach 1:
The patent merges the coating process with the synthesis process, eliminating the need for separate coating equipment and processing steps. This integration reduces manufacturing cost by using the same sintering furnace and process parameters for both cathode formation and solid electrolyte coating
Solution Approach 2:
The patent optimizes the sintering temperature and holding time parameters to achieve effective coating formation. By carefully controlling these parameters, the solid electrolyte coating forms with good quality while minimizing energy consumption and processing time, thereby reducing manufacturing cost
3Quantity of substance
If high voltage charging is used to achieve high energy density, then capacity is improved, but the cathode material decomposes and performance degrades
Solution Approach 1:
The patent applies beforehand cushioning by forming a solid electrolyte coating layer on the cathode material surface before the battery undergoes high voltage charging. This pre-formed coating acts as a protective barrier that prevents electrolyte decomposition and cathode material degradation during high voltage operation, thereby maintaining material stability while enabling high energy density
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 method improves the rate and cycle performance of LMNO cathode materials by providing a protective coating that prevents surface damage and structural defects, ensuring low impedance and efficient charge/discharge performance while reducing manufacturing costs.
Implementation Method 1
mixing the nickel-manganese compound material and the solid electrolyte material in a mechanical mixing
Implementation Method 2
providing a lithium source, mixing the lithium source and the composite material, and sintering to form the composite cathode material
Data Source
AI summary
A preparation method of a composite cathode material is disclosed and includes steps of: (a) providing a nickel-manganese compound material, wherein the nickel-manganese compound material is NixMny(OH)2 or NixMnyO, x+y=1; (b) providing a solid electrolyte material, and mixing the nickel-manganese compound material and the solid electrolyte material in a mechanical mixing into a composite material, wherein the solid electrolyte material has a weight percentage relative to the nickel-manganese compound material, and the weight percentage is ranged from 0.2 wt. % to 1.0 wt. %; and (c) providing a lithium source, mixing the lithium source and the composite material, and sintering to form the composite cathode material, wherein the composite cathode material includes a core and a coating layer, the core is made of LiNi2xMn2yO4 and coated by the coating layer, and the coating layer is made of the solid electrolyte material.