Non-aqueous Electrolyte Additive for High-Temperature Battery Stability
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Solution Overview
Problem
Lithium secondary batteries face issues with electrode deterioration due to side reactions and metal ion elution, leading to reduced stability and increased swelling, especially at high temperatures, which affects their performance and durability.
Innovation Solution
A non-aqueous electrolyte containing a specific compound represented by Formula 1, which forms robust films on electrodes to stabilize the interface and suppress metal ion elution, improving high-temperature performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If high-Ni content positive electrode active material is used to achieve high energy density, then battery capacity is improved, but electrode stability deteriorates due to side reactions and metal ion elution
Solution Approach 1:
The patent introduces a specific additive compound (Formula 1) as an intermediary substance between the high-Ni positive electrode and the electrolyte. This additive forms a protective interface film that mediates the interaction, preventing direct harmful reactions while allowing ionic transport, thus resolving the contradiction between achieving high capacity and maintaining stability.
Solution Approach 2:
The patent modifies the chemical composition parameters of the electrolyte by incorporating a specific additive with defined molecular structure (Formula 1) containing sultone and carbonyl groups. This parameter change in the electrolyte composition enables the formation of a stable protective film on the electrode surface, allowing high-Ni materials to be used without excessive degradation.
2Quantity of substance
If the positive electrode potential is increased to achieve high capacity, then battery energy density is improved, but the rate of metal ion elution and negative electrode deterioration accelerates
Solution Approach 1:
The additive compound (Formula 1) performs preliminary protective action by forming a stable interface film on the positive electrode surface before significant metal ion elution can occur. This pre-formed protective layer prevents the acceleration of deterioration that would normally occur at high potentials, allowing the battery to operate at high voltage without excessive degradation.
3Power
If the battery is operated at high temperatures to improve performance, then output is improved, but gas generation and swelling phenomenon increase
Solution Approach 1:
The patent converts the potentially harmful thermal effects at high temperatures into a beneficial outcome. The specific additive (Formula 1) is designed to form an exceptionally stable protective film that not only withstands but actually suppresses gas-generating side reactions at elevated temperatures. The high-temperature operation conditions that would normally accelerate degradation are instead used to form and stabilize the protective interface, converting the harmful thermal energy into a beneficial stabilizing effect.
4Reliability
If conventional electrolyte additives are used to form SEI film, then negative electrode protection is improved, but positive electrode stability and overall battery durability are insufficient
Solution Approach 1:
The patent employs a multi-functional additive compound (Formula 1) that simultaneously protects both the positive and negative electrodes, unlike conventional additives that primarily focus on SEI formation at the negative electrode. This single compound performs multiple functions: forming protective films on both electrodes, suppressing metal ion elution from the positive electrode, and preventing gas generation, thereby achieving comprehensive protection and extended battery durability.
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 compound enhances the stability of the electrode-electrolyte interface, reducing resistance and preventing electrode deterioration, resulting in improved high-temperature cycle characteristics and storage performance of lithium secondary batteries.
Implementation Method 1
forming a stable SEI film on the negative electrode
Implementation Method 2
increasing the passivation ability of a solid electrolyte interphase (SEI)
Implementation Method 3
suppressing the elution of metal ions from the positive electrode and forming a stable SEI film on the negative electrode, thereby reducing the swelling phenomenon in secondary batteries
Implementation Method 4
as charging and discharging proceeds
Data Source
AI summary
The present invention provides a non-aqueous electrolyte comprising a lithium salt, an organic solvent, and a compound of chemical formula 1 as an additive. [Chemical formula 1] In chemical formula 1, n is an integer of 0 or 1, R1 is any one selected from the group consisting of R, a C1-10 alkyl group capable of being substituted with fluorine, a C2-10 alkenyl group capable of being substituted with fluorine, a C2-10 alkynyl group capable of being substituted with fluorine, OR', OCOR', F and CH2PO(R)2, and R' can be any one selected from the group consisting of a C1-10 alkyl group capable of being substituted with fluorine, a C2-10 alkenyl group capable of being substituted with fluorine, a C2-10 alkynyl group capable of being substituted with fluorine, and PO(R)2. In chemical formula 1 and R1, R is a structure represented by the following chemical formula 2. [Chemical formula 2] In chemical formula 2, each of Rx and Ry is independently H or F.