Rechargeable Lithium Battery Electrolyte for High-Temperature Ignition Control
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Solution Overview
Problem
Rechargeable lithium batteries face issues with ignition and explosion at high temperatures, which can lead to a cascade of heat propagation and failure in battery modules or packs, due to increased resistance and thermal runaway.
Innovation Solution
An electrolyte formulation for rechargeable lithium batteries incorporating a non-aqueous organic solvent, a lithium salt, a cyclic monomolecular sulfate additive that decomposes to form a solid electrolyte interface, and a polymer additive that increases viscosity and reduces ionic conductivity at high temperatures, thereby suppressing ignition and explosion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional electrolytes are used in rechargeable lithium batteries, then the batteries can operate at high temperatures, but the resistance increases and ignition/explosion risk occurs
Solution Approach 1:
The patent modifies the chemical composition parameters of the electrolyte by introducing specific additives (cyclic sulfate ester compounds and phosphorus-containing compounds) to change the thermal behavior of the system. These additives alter the decomposition temperature and reaction pathways, enabling the electrolyte to maintain stability at high temperatures while preventing ignition and explosion through controlled chemical reactions.
Solution Approach 2:
The patent introduces intermediary substances (cyclic sulfate ester compounds and phosphorus-containing compounds) that act as mediators between the electrodes and the electrolyte. These intermediaries form protective interface layers on the electrode surfaces, which prevent direct contact between reactive components at high temperatures, thereby eliminating ignition and explosion risks while maintaining operational temperature.
2Object-affected harmful factors
If one battery cell ignites or explodes at high temperature, then heat propagates to adjacent cells, but the new electrolyte prevents this cascade effect
Solution Approach 1:
The patent converts the potentially harmful thermal runaway process into a beneficial controlled reaction. When temperature rises, the phosphorus-containing compounds undergo exothermic decomposition that absorbs excess heat and releases non-flammable gases, transforming the dangerous thermal runaway into a controlled heat dissipation process that protects adjacent cells from ignition.
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 effectively prevents or reduces ignition and explosion of lithium battery cells at high temperatures, even if adjacent cells ignite, by rapidly increasing viscosity and reducing ionic conductivity, thus preventing temperature increases.
Implementation Method 1
a first additive including at least one selected from an additive represented by Chemical Formula 1 and an additive represented by Chemical Formula 2
Implementation Method 2
a second additive represented by Chemical Formula 3
Data Source
AI summary
This disclosure relates to an electrolyte for a rechargeable lithium battery and a rechargeable lithium battery including the same. Some embodiments provide an electrolyte additive for a rechargeable lithium battery including a non-aqueous organic solvent; a lithium salt; a first additive including at least one selected from an additive represented by Chemical Formula 1 and an additive represented by Chemical Formula 2; and a second additive represented by Chemical Formula 3: