Non-Aqueous Electrolyte Additive for High-Temperature Li-Ion Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium secondary batteries face issues with metal ion elution from the positive electrode, leading to negative electrode deterioration and swelling due to side reactions and gas generation, particularly at high temperatures, which degrade performance and stability.
Innovation Solution
A non-aqueous electrolyte containing a coumarin-based compound with an isocyanate group is used to form a stable film on the electrodes, scavenging Lewis acids and reactive oxygen compounds, thereby suppressing metal ion elution and gas generation, enhancing high-temperature cycle and storage characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If high-voltage operation or high-nickel positive electrode materials are used to increase battery capacity and energy density, then battery capacity and energy density are improved, but metal ion elution from the positive electrode increases and negative electrode deterioration accelerates
Solution Approach 1:
The patent introduces a film-forming additive as an intermediary substance that mediates between the high-voltage/high-nickel positive electrode and the electrolyte/negative electrode. This additive forms a protective interface layer that prevents direct harmful interactions, allowing the battery to operate at high voltages with high-nickel materials without suffering from metal ion elution and electrode deterioration.
Solution Approach 2:
The film-forming additive performs preliminary protective action by forming a stable film on the positive electrode surface before metal ion elution can occur. This pre-formed protective layer prevents the subsequent harmful effects of metal ion elution and protects the negative electrode from deterioration, countering the adverse effects before they manifest.
2Power
If the positive electrode potential is increased to enhance battery performance, then battery output and capacity are improved, but metal ion elution and negative electrode deterioration are accelerated
Solution Approach 1:
The film-forming additive serves as a protective intermediary layer on the positive electrode surface, mediating between the high-potential electrode and the electrolyte. This intermediary film prevents metal ion elution even when the positive electrode operates at elevated potentials, allowing high power output without the harmful effects of metal ion dissolution.
Solution Approach 2:
The patent employs a thin film formed by the film-forming additive on the positive electrode surface. This flexible protective film allows the electrode to maintain high potential for improved power output while the film itself acts as a barrier preventing metal ion elution and protecting against harmful chemical reactions.
3Productivity
If the battery is exposed to high temperatures to accelerate reactions or improve performance, then reaction kinetics are improved, but side reactions increase and battery swelling is accelerated
Solution Approach 1:
The film-forming additive creates a protective intermediary layer that mediates between the electrode and the electrolyte under high-temperature conditions. This film prevents direct contact and harmful side reactions, allowing the battery to operate at elevated temperatures with improved reaction kinetics without generating excessive gas or suffering from swelling.
Solution Approach 2:
The film-forming additive provides beforehand cushioning by forming a protective film that cushions against the harmful effects of high-temperature operation. This pre-formed film prevents direct harmful interactions between the electrode and electrolyte, cushioning against gas generation and swelling that would otherwise occur during high-temperature operation.
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 electrolyte improves the lithium secondary battery's high-temperature performance by reducing metal ion elution, preventing electrode decomposition, and minimizing swelling, thus enhancing overall stability and longevity.
Implementation Method 1
forming a stable film on the positive/negative electrodes
Implementation Method 2
remove a Lewis acid of a lithium salt (HF scavenging effect) which may be generated during high-temperature exposure
Implementation Method 3
suppressing the decomposition of the electrolyte and the generation of gas (O2 scavenging effect) by binding a reactive oxygen compound generated in the positive electrode and a coumarin structure
Data Source
AI summary
A non-aqueous electrolyte includes: a lithium salt; an organic solvent; and an additive, wherein the additive includes a compound represented by Formula 1 below, and such non-aqueous electrolyte may have excellent effects of film protection, O2 scavenging, and HF scavenging of the electrodes, and thus may improve cycle characteristics and high-temperature storage characteristics of the lithium secondary battery including the non-aqueous electrolyte:all the variables are described herein.