SO2 Electrolyte Chelate Salts for Stable Rechargeable Cells
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Solution Overview
Problem
Existing rechargeable lithium-ion cells face issues with stability, long-term operational reliability, safety risks due to flammability, and corrosive hydrolysis products, particularly in high-energy applications like vehicle propulsion, and SO₂-based electrolytes suffer from limited solubility of conducting salts and reactivity with residual water.
Innovation Solution
An SO₂-based electrolyte with specific conducting salts forming chelate complexes in the electrolyte, ensuring high solubility, wide electrochemical window, and resistance to decomposition, along with a rechargeable battery cell design that minimizes water reactivity and enhances stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If organic solvents are used in lithium-ion cells, then good electrical energy and performance data are achieved, but flammability and safety risks occur
Solution Approach 1:
The patent replaces flammable organic solvents with sulfur dioxide (SO2), an inert gas that does not support combustion. This substitution eliminates the flammability hazard while maintaining the electrolyte's ability to dissolve conducting salts and enable ion transport, thus resolving the contradiction between energy performance and safety.
Solution Approach 2:
The patent employs a composite electrolyte system combining SO2 with specific conducting salts (LiAlCl4, LiGaCl4, LiInCl4) to create a non-flammable yet electrically conductive medium. This composite approach maintains the necessary electrical properties while eliminating the harmful flammability of pure organic solvents.
2Use of energy by moving object
If organic solvents are used in lithium-ion cells, then good electrical energy and performance data are achieved, but long-term operational reliability deteriorates
Solution Approach 1:
By using inert SO2 instead of organic solvents, the electrolyte becomes resistant to decomposition and degradation over time. This inert environment prevents the chemical reactions that lead to electrolyte breakdown, thereby improving long-term operational reliability while maintaining electrical performance.
Solution Approach 2:
The patent changes the fundamental chemical parameter of the electrolyte from organic to inorganic (SO2-based), which fundamentally alters the stability and reliability characteristics while preserving the electrical conductivity needed for energy storage functionality.
3Object-affected harmful factors
If SO2-based electrolytes are used, then flammability and operational reliability are improved, but solubility of conducting salts deteriorates
Solution Approach 1:
The patent modifies the chemical parameters of SO2 by combining it with specific conducting salts (LiAlCl4, LiGaCl4, LiInCl4) in controlled proportions. This parameter adjustment optimizes the solubility and ionic conductivity of the electrolyte while maintaining the non-flammable property of SO2.
Solution Approach 2:
The patent creates a composite electrolyte system where SO2 is combined with specific conducting salts to form a homogeneous mixture with optimized solubility. This composite approach ensures adequate ion transport while maintaining the safety advantages of SO2.
4Object-affected harmful factors
If SO2-based electrolytes are used, then safety risks are reduced, but reactivity with residual water increases
Solution Approach 1:
The patent employs preliminary drying processes and water removal techniques during battery assembly to eliminate residual moisture before introducing the SO2-based electrolyte. This preliminary action prevents water-SO2 reactions that would generate harmful hydrolysis products, thereby maintaining both safety and chemical stability.
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 provides rechargeable battery cells with improved energy density, high operational reliability, extended lifespan, and reduced safety risks, suitable for high-voltage operations and harsh environments.
Implementation Method 1
The conducting salt can form a liquid solvate complex with the gaseous SO2, thereby binding the SO2 and significantly reducing its vapor pressure compared to pure SO2.
Implementation Method 2
At least one ion of the conducting salt (anion or cation) is mobile enough in the electrolyte to allow charge transport between the electrodes via ionic conduction, which is essential for the function of the rechargeable battery cell.
Implementation Method 3
These electrochemical processes lead directly or indirectly to the release of electrons into the external circuit or the absorption of electrons from the external circuit.
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
SO2-based electrolyte and rechargeable battery cell (2, 20, 40) with this electrolyte, which contains at least a first conducting salt according to the following formula (I), wherein M is a metal selected from the group consisting of alkali metals, alkaline earth metals, group 12 metals and aluminium; x is an integer from 1 to 3; R1, R2, R3 and R4 are independently selected from the group consisting of a halogen atom, a hydroxyl group, a chemical group -OR5 and a chelating ligand jointly formed by at least two of the substituents R1, R2, R3 and R4 and coordinated to Z; wherein R1, R2, R3 and R4 are neither four halogen atoms nor four chemical groups -OR5, in particular alkoxy groups; wherein the substituent R5 is selected from the group formed by C1-C10 alkyl, C2-C10 alkenyl, C2-C10 alkynyl, C3-C10 cycloalkyl, C6-C14 aryl and C5-C14 heteroaryl; and wherein Z is aluminium or boron.