Electrolyte Composition for Stable SEI in High-Density Batteries
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The increasing demand for high-energy density batteries with compacted electrodes and high-capacity materials leads to performance issues such as poor cycle performance, low-temperature performance, and lithium plating during charging, hindering the development of secondary batteries.
Innovation Solution
An electrolyte composition including specific compounds like those in formulas 1, 2, 3, 4, and 6, along with a nitrile compound and fluorosulfonic anhydride, is used to form a stable solid electrolyte interface (SEI) film, reducing side reactions and enhancing lithium ion conductivity, thus improving cycle and high-temperature performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If compacted density of positive and negative electrodes is increased to achieve small volume and high energy density, then energy density is improved, but cycle performance deteriorates
Solution Approach 1:
The patent introduces a compound of formula (1) as an intermediary substance in the electrolyte that mediates between the electrode and electrolyte interface. This compound forms a stable protective film that prevents direct harmful interactions, thereby maintaining cycle performance while allowing high energy density operation with compacted electrodes
Solution Approach 2:
The patent changes the chemical composition parameters of the electrolyte by incorporating a specific compound of formula (1) with defined molecular structure characteristics. This parameter change in electrolyte composition enables the formation of a stable interface layer that resolves the contradiction between electrode compaction and cycle stability
2Quantity of substance
If high-capacity negative electrode materials such as lithium metal and Si/C are used to achieve high energy density, then capacity is improved, but cycle performance deteriorates
Solution Approach 1:
The compound of formula (1) acts as an intermediary protective layer between high-capacity negative electrode materials (lithium metal and Si/C) and the electrolyte. This intermediary film prevents direct degradation reactions, enabling these high-capacity materials to maintain stable cycle performance
Solution Approach 2:
The patent applies beforehand cushioning by having the compound of formula (1) pre-form a protective film on the negative electrode surface before the electrode materials undergo degradation. This prior protective layer cushions against the harmful effects of volume expansion and chemical reactions during cycling
3Ease of operation
If low-temperature charging is performed to meet user needs, then usability is improved, but lithium plating occurs causing performance deterioration
Solution Approach 1:
The compound of formula (1) serves as an intermediary substance that modifies the electrode-electrolyte interface to prevent lithium plating during low-temperature charging. This protective film facilitates smoother lithium ion insertion and extraction, reducing the tendency for lithium metal deposition on the electrode surface
Solution Approach 2:
The patent changes the interfacial properties parameters by introducing the compound of formula (1), which alters the electrochemical characteristics of the electrode surface. This parameter change reduces the overpotential for lithium ion insertion, preventing lithium plating even at low temperatures
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 proposed electrolyte composition improves high-temperature and room-temperature cycle performance, high-temperature storage, and high-rate discharge performance by forming a compact and uniform SEI film, reducing polarization and electrolyte consumption.
Implementation Method 1
it has been found that when a compound of formula (1) is used as an electrolyte additive, a stable solid electrolyte interface (SEI) protective film is easily formed on a negative electrode in a chemical conversion process
Data Source
AI summary
An electrolyte includes a compound of formula 1:formula 1.R1 and R2 are each independently selected from H, halogen atom, a substituted or unsubstituted C1-10 alkyl group, a substituted or unsubstituted C3-10 cycloalkyl group, a substituted or unsubstituted C2-10 alkenyl group, a substituted or unsubstituted C2-10 alkynyl group, a substituted or unsubstituted C1-10 alkoxy group, a substituted or unsubstituted C6-10 aryl group, a substituted or unsubstituted C3-10 heteroaryl group, or any combination thereof. R is selected from a substituted or unsubstituted C1-10 alkyl group, a substituted or unsubstituted C3-10 cycloalkyl group, a substituted or unsubstituted C2-10 alkenyl group, a substituted or unsubstituted C2-10 alkynyl group, a substituted or unsubstituted C1-10 alkoxy group, a substituted or unsubstituted C6-10 aryl group or a substituted or unsubstituted C3-10 heteroaryl group, a substituted or unsubstituted C3-10 heterocycloalkyl group, a butyrolactam group,or any combination thereof.