Cyclic Sulfonic Acid Ester Electrolyte for Battery Storage Stability
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Solution Overview
Problem
Existing lithium ion secondary batteries face issues with degradation due to decomposition reactions of the electrolyte solution, leading to reduced storage characteristics and self-discharge capacity, particularly when using unsubstituted disulfonic acid esters which cause sedimentation and clog liquid injection nozzles, affecting production yield and battery reliability.
Innovation Solution
A nonaqueous electrolyte solution containing a cyclic sulfonic acid ester with specific substituents, combined with a positive electrode composed of a lithium manganese composite oxide and a lithium transition metal composite compound, forms a protective film on the electrode surface, reducing decomposition reactions and enhancing storage stability and self-discharge properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If unsubstituted disulfonic acid esters are used as electrolyte solution additives, then film forming ability is improved, but sedimentation occurs and liquid injection nozzles are clogged
Solution Approach 1:
The patent introduces substituted disulfonic acid esters where R1 and R2 are not both hydrogen atoms, modifying the chemical structure parameters of the additive to prevent sedimentation while maintaining film forming ability. This structural modification changes the physical and chemical properties of the electrolyte solution to eliminate clogging issues.
Solution Approach 2:
The patent combines substituted disulfonic acid esters with specific lithium salts and solvent mixtures to create a composite electrolyte solution system. This composite approach ensures that the film forming additive works synergistically with other components to maintain both performance and manufacturability.
2Reliability
If electrolyte solution decomposition reactions occur, then charge-discharge reactions are inhibited, but storage characteristics and self-discharge capacity are reduced
Solution Approach 1:
The patent uses film forming additives that react first to create protective films on electrode surfaces before any harmful decomposition reactions can occur. This preliminary protective action prevents subsequent decomposition and maintains both charge-discharge efficiency and storage characteristics throughout the battery lifecycle.
Solution Approach 2:
The film forming additives act as intermediaries between the electrolyte solution and electrode surfaces, creating protective barrier films that prevent direct harmful interactions. These intermediary films block decomposition reactions while allowing necessary lithium ion transport, thus protecting storage characteristics and maintaining reaction efficiency.
3Quantity of substance
If high energy density is pursued, then battery capacity increases, but decomposition reactions are promoted and characteristics degrade
Solution Approach 1:
The patent modifies the electrolyte solution composition parameters by introducing specific substituted disulfonic acid esters and optimizing solvent ratios. These parameter changes enable the system to achieve high energy density while the protective films formed by the additives prevent decomposition reactions, thus maintaining characteristic stability.
Solution Approach 2:
The patent creates a composite electrolyte system combining multiple solvents, lithium salts, and film forming additives in specific proportions. This composite formulation achieves high energy density through optimized composition while the synergistic interaction of components prevents decomposition, maintaining long-term reliability.
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 significantly improves the storage characteristics and self-discharge performance of lithium ion secondary batteries by suppressing decomposition reactions and maintaining capacity, while preventing sedimentation and ensuring high production yields.
Implementation Method 1
an electrolyte solution additive having a film forming ability is added to an electrolyte solution
Implementation Method 2
forming a protection film on the electrode surface to thereby suppress the above decomposition reaction
Implementation Method 3
decomposition reactions of an electrolyte solution solvent and a supporting electrolyte salt may take place in some cases
Implementation Method 4
the desorption and absorption reactions of lithium ions occur at the interface between an electrode and an electrolyte solution
Data Source
AI summary
A nonaqueous electrolyte solution secondary battery having an electrode element having a positive electrode and a negative electrode disposed so as to face each other, a nonaqueous electrolyte solution, and an outer package housing the electrode element and the nonaqueous electrolyte solution, wherein the nonaqueous electrolyte solution contains a cyclic sulfonic acid ester represented by the general formula (1), and a positive electrode active material in the positive electrode is a mixture of a lithium manganese composite oxide having a spinel structure and a lithium transition metal composite compound having a layered rock salt structure.wherein, in the formula (1), R1 and R2 are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a halogen group or an amino group with the proviso that R1 and R2 are not hydrogen atoms at the same time; R3 represents a linkage group selected from the group consisting of an alkylene group having 1 to 5 carbon atoms, a carbonyl group, a sulfonyl group, a fluoroalkylene group having 1 to 6 carbon atoms, and a divalent group having 2 to 6 carbon atoms in which alkylene units or fluoroalkylene units are bonded through an ether group.