Prussian Blue Analogue Electrode Water Control for Sodium-Ion Battery Swelling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Sodium-ion batteries face poor electrochemical performance due to issues with gas production, charge-discharge performance, and cycle performance, primarily attributed to the positive electrode plate's active material, which experiences water electrolysis and side reactions, leading to swelling and capacity degradation.
Innovation Solution
A positive electrode plate comprising a prussian blue analogue material with a controlled water content of 100µg/g to 5000µg/g and a specific surface area of 5m²/g to 20m²/g, ensuring coordinated water supports the crystal structure and minimizing electrolysis and side reactions, thereby enhancing charge-discharge and cycle performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the water content in the positive electrode active material film is not controlled, then the preparation process is simpler, but water electrolysis occurs during charge-discharge process causing gas production and swelling
Solution Approach 1:
The patent applies preliminary action by controlling the water content of the positive electrode active material film before battery assembly. The water content is precisely controlled to 100-5000 µg/g through the preparation process, preventing water electrolysis and gas production during subsequent charge-discharge operations. This advance control eliminates the need for complex in-situ water management systems.
2Object-generated harmful factors
If the water content in the positive electrode active material film is too low, then gas production is reduced, but the crystal structure collapses due to coordinated water being dried out
Solution Approach 1:
The patent applies parameter changes by precisely controlling the water content parameter within the optimal range of 100-5000 µg/g. This parameter control ensures that coordinated water remains in the crystal structure to maintain stability, while excess water that would cause gas production is eliminated. The specific surface area is also controlled at 5-20 m²/g to regulate water adsorption and maintain the balance between gas production prevention and crystal structure stability.
3Object-generated harmful factors
If the specific surface area of the prussian blue analogue material is not controlled, then the material is easier to prepare, but water adsorption increases leading to more side reactions with electrolyte
Solution Approach 1:
The patent applies parameter changes by controlling the specific surface area parameter of the prussian blue analogue material to be 5-20 m²/g. This parameter optimization reduces water adsorption on the material surface, thereby minimizing side reactions with the electrolyte. The controlled specific surface area prevents excessive water uptake while maintaining the material's electrochemical activity and preparing the material through standard synthesis methods.
4Stability of the object's composition
If the water content in the positive electrode active material film is high, then the crystal structure is maintained, but water is electrolyzed during charge-discharge process causing swelling
Solution Approach 1:
The patent applies parameter changes by precisely controlling the water content parameter within the optimal range of 100-5000 µg/g. This controlled water content ensures that sufficient coordinated water remains in the crystal structure to maintain stability, while excess free water that would be electrolyzed and cause swelling is eliminated. The specific surface area control at 5-20 m²/g further regulates water content to achieve this balance.
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 controlled water content and specific surface area of the prussian blue analogue material improve gas production and maintain excellent charge-discharge and cycle performance without capacity loss, making the sodium-ion battery suitable for large-scale production.
Implementation Method 1
water electrolysis and side reactions, leading to swelling and capacity degradation
Data Source
AI summary
The present invention provides a positive electrode plate, a preparation method thereof and a sodium-ion battery. The positive electrode plate comprises a positive electrode current collector and a positive electrode active material film. The positive electrode active material film provided on the positive electrode current collector and comprises a positive electrode active material. The positive electrode active material comprises a prussian blue analogue material, a molecular formula of the prussian blue analogue material is AxM[M'(CN)6]y, a water content of the positive electrode active material film is 100µg/g∼5000µg/g. The water content of the positive electrode active material film is controlled within a certain range, which can not only ensure the sodium-ion battery do not seriously swell during charge-discharge process, but also can ensure sodium-ion battery have excellent charge-discharge performance and cycle performance.