Lithium Battery Electrolyte Additive for Overcharge Safety
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Solution Overview
Problem
Current redox shuttle additives in lithium batteries are insufficient for ensuring safety during overcharging, particularly in high-capacity batteries, as they fail to provide adequate protection against thermal runaway and electrode instability.
Innovation Solution
An electrolyte composition including a non-aqueous organic solvent, a lithium salt, and a specific additive represented by Formula 1, which initiates polymerization at high voltages to increase electrode resistance and consume overcharge current, thereby preventing thermal runaway and enhancing battery safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional redox shuttle additives are used in high-capacity lithium batteries, then the battery can achieve high energy density, but the battery safety deteriorates during overcharging conditions
Solution Approach 1:
The patent changes the chemical parameters of the additive by introducing a specific heterocyclic compound structure with nitrogen-containing rings and fluorine substitution. This structural modification enables the additive to undergo polymerization at overcharge potentials, transforming it from a conventional redox shuttle to a polymerization-type safety additive that provides both high capacity compatibility and improved safety
Solution Approach 2:
The patent creates a composite protective film on the electrode surface consisting of the polymerized additive compound. This composite structure combines the benefits of high energy density operation with enhanced safety characteristics, as the polymerized film acts as a protective barrier that prevents thermal runaway while allowing normal charging cycles
2Power
If the battery operates at high capacity, then the energy output increases, but the risk of thermal runaway increases due to insufficient overcharge protection
Solution Approach 1:
The additive compound is designed to preemptively counteract overcharge conditions by polymerizing at specific voltage thresholds. This preliminary anti-action occurs before thermal runaway can initiate, as the polymerized film forms a protective barrier that prevents the harmful thermal reactions even when the battery is operated at high capacity levels
3Device complexity
If conventional electrolyte additives are used, then the electrolyte composition remains simple, but the ability to prevent overcharge reactions is insufficient
Solution Approach 1:
The patent achieves superior overcharge protection with minimal compositional complexity by carefully selecting specific parameter ranges: the heterocyclic compound contains nitrogen-containing rings with fluorine substitution at defined positions, and is used at a concentration of 0.01-5% by weight. This precise parameter optimization provides effective safety without requiring complex multi-component formulations
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 effectively inhibits overcharging and improves battery safety by coating electrode surfaces and consuming overcharge current, reducing the risk of thermal runaway and ensuring stable operation even during high-capacity charging.
Implementation Method 1
the polymerization reaction of these redox shuttle additives consumes the overcharge current to improve battery safety
Implementation Method 2
which initiates polymerization at high voltages to increase electrode resistance and consume overcharge current
Implementation Method 3
close pores of a separator through quick and uniform fusion of the separator to inhibit an overcharge reaction
Data Source
AI summary
The electrolyte for a lithium battery includes a non-aqueous organic solvent, a lithium salt, and an additive of the following Formula 1:wherein, X is O or S,Y1, Y2, and Y3 are the same or different from each other and selected from O, S, CR2, and NR, where here R is H, a halogen, or an alkyl having a carbon number of less than or equal to 8, or neighboring alkyl groups are combined to each other to form a cycle or hetero cycle, andRa to Rd are the same or different from each other and selected from H, a halogen, an alkoxy group having a carbon number of less than or equal to 8, and an unsaturated or saturated alkyl group having a carbon number of less than or equal to 8, or neighboring alkyl groups are combined to each other to form a cycle or hetero cycle.