Cylindrical Li-Ion Cell Housing Powder Coating Against HF Corrosion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing techniques for inhibiting corrosion of cylindrical non-aqueous electrolyte secondary battery outer housings, such as those using alkaline compounds like butylamine, are unstable and prone to volatilization, failing to provide reliable protection.
Innovation Solution
Applying a powder of hydroxide, oxide, or carbonate compounds, such as aluminum hydroxide, magnesium hydroxide, or lithium carbonate, to the inner surface of the outer housing between the groove portion and the opening end, which neutralizes hydrogen fluoride and prevents corrosion without volatility issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If alkaline compound such as butylamine is applied to the inner surface of the outer housing, then corrosion inhibition is achieved, but the compound volatilizes and protection becomes unstable
Solution Approach 1:
The patent changes the physical state parameter of the alkaline compound from liquid (butylamine) to solid powder form. This parameter change eliminates volatilization while maintaining the corrosion inhibition function, as solid compounds do not evaporate at battery operating temperatures.
Solution Approach 2:
The patent uses a solid powder coating that remains stable throughout the battery's service life, replacing the volatile liquid compound that required frequent reapplication or provided only temporary protection. The solid powder provides long-term stable protection without degradation.
2Reliability
If sealant including alkaline compound is applied to enhance airtightness, then corrosion protection is improved, but the sealant complexity and application process become more complex
Solution Approach 1:
The patent extracts the alkaline compound function from the sealant matrix, applying only the necessary amount of solid powder to the specific region where corrosion protection is needed. This separates the corrosion protection function from the sealing function, simplifying both the material composition and application process.
Solution Approach 2:
The patent applies the alkaline compound powder only to the specific region of the inner surface where corrosion risk exists (above the groove portion), rather than coating the entire housing. This localized application reduces material usage and simplifies the manufacturing process while maintaining effective protection.
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 solution effectively and stably inhibits corrosion of the outer housing, ensuring long-term protection against hydrogen fluoride reaction, as demonstrated by the absence of corrosion in batteries treated with these compounds in accelerated tests.
Implementation Method 1
powder of one or more compounds selected from a group consisting of hydroxide, oxide, and carbonate... neutralizes hydrogen fluoride and prevents corrosion
Data Source
AI summary
Provided is a secondary battery in which corrosion of an exterior body is stably suppressed. A non-aqueous electrolyte secondary battery according to an embodiment of the present disclosure comprises: an exterior body having a bottomed cylindrical shape and having a grooving portion in an opening portion; an electrode body and a non-aqueous electrolyte housed in the exterior body; and a sealing body caulked and fixed between the grooving portion and an opening end in the opening, wherein in a portion from the grooving portion of the inner surface of the exterior body to the open end portion, a powder of at least one among compounds selected from the group consisting of hydroxides, oxides, and carbonates is present.