Sodium-Ion Cathode Material for Air-Stable Layered Oxide Structure
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Solution Overview
Problem
The Na x MO 2 cathode materials in sodium ion batteries suffer from poor air stability due to water absorption and structural collapse during charging and discharging, leading to degraded cycle stability and low volumetric change.
Innovation Solution
A sodium ion battery cathode material with a specific XRD peak arrangement and microcrystalline size ratio, combined with a pre-sintering process, to enhance air stability and structural stability while maintaining high volume energy density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If layered oxide cathode material (Na x MO 2) is used in sodium ion batteries, then high energy density and low cost are achieved, but air stability deteriorates due to water absorption and conversion into other compounds
Solution Approach 1:
The patent applies composite materials by combining layered oxide with three-dimensional oxide structures to create a composite cathode material. This composite structure leverages the high energy density of layered oxide while the three-dimensional oxide component provides structural stability and resistance to water absorption, thereby resolving the contradiction between energy density and air stability.
Solution Approach 2:
The patent applies local quality by creating a hierarchical structure where different regions of the cathode material have different functions. The layered oxide regions provide high energy density, while the three-dimensional oxide regions provide structural stability and moisture resistance. This spatial differentiation of material properties allows simultaneous achievement of high energy density and air stability.
2Quantity of substance
If layered oxide cathode material is used, then high energy density is achieved, but structural stability deteriorates due to large volumetric change during charging and discharging
Solution Approach 1:
The patent uses composite materials combining layered oxide with three-dimensional oxide structures. The layered oxide provides high energy density through efficient ion pathways, while the three-dimensional oxide provides structural stability by accommodating volumetric changes. This composite approach resolves the contradiction between energy density and structural stability.
Solution Approach 2:
The patent applies parameter changes by modifying the crystal structure from purely layered to a composite structure with three-dimensional characteristics. This structural parameter change enables the material to maintain high energy density while reducing volumetric expansion during cycling, thereby improving structural stability.
3Ease of manufacture
If conventional cathode materials are used, then manufacturing simplicity is maintained, but volumetric energy density is low
Solution Approach 1:
The patent applies preliminary action by pre-sintering the layered oxide precursor before final assembly into the battery. This pre-treatment step optimizes the material structure in advance, improving packing density and volumetric energy density while maintaining relatively simple manufacturing processes. The pre-sintering prepares the material for higher density without requiring complex manufacturing steps.
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 cathode material exhibits improved air stability, structural stability, and enhanced electrochemical properties, including higher sodium ion mobility and cycle stability.
Implementation Method 1
The cathode material has improved air stability and structural stability on the premise of ensuring a high volume energy density; in addition, a use of the cathode material in the sodium ion battery can effectively improve the electrochemical properties of the sodium ion battery
Data Source
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AI summary
The present disclosure relates to the technical field of sodium-ion batteries, in particular to a sodium ion battery cathode material, a preparation method thereof, and a sodium ion battery, in an XRD spectrogram of the cathode material, the characteristic diffraction peak A of (003) crystal plane and the characteristic diffraction peak B of (104) crystal plane are arranged at 2θ of 15-19° and 39-44°, respectively; wherein the microcrystalline size DA of the characteristic diffraction peak A and the microcrystalline size DB of the characteristic diffraction peak B satisfy the following condition: 1.3≤DA/DB≤2.5, wherein DA and DB correspond to the microcrystalline sizes of the (003) crystal plane and the (104) crystal plane in the perpendicular line direction, respectively. The cathode material has improved air stability and structural stability on the premise of ensuring high volume energy density; in addition, the use of the cathode material in the sodium ion battery can effectively improve the electrochemical properties of the sodium ion battery.