Electrolyte Composition for Lithium-Ion Battery Thermal Stability
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Solution Overview
Problem
Lithium-ion batteries face limitations due to the low chemical stability of LiPF6 electrolyte salt, which restricts operating temperature range and scalability, and generates toxic compounds during thermal runaway, hindering the development of high-performance and cost-effective batteries.
Innovation Solution
A solvent mixture comprising at least two carbonate solvents, such as EC, DMC, and PC, with additives like SCN and FEC, and a lithium salt like LiDFOB, which enhances stability and compatibility with various anodes and cathodes, allowing for high temperature operation and extended cycle life without cobalt or nickel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If LiPF6 electrolyte salt is used, then electrolyte conductivity is achieved, but chemical stability deteriorates and toxic compounds are generated during thermal runaway
Solution Approach 1:
The patent removes LiPF6 electrolyte salt from the battery system entirely, replacing it with alternative salts such as LiBF4, LiPF5, LiClO4, or LiTFSI combined with carbonate solvents. This extraction eliminates the source of toxic HF generation while maintaining electrolyte functionality through alternative chemical compositions.
Solution Approach 2:
The patent changes the chemical composition parameters of the electrolyte by substituting LiPF6 with other lithium salts and adjusting the solvent mixture ratios (EC, DMC, PC). This parameter change modifies the chemical stability characteristics and thermal behavior of the electrolyte system to prevent toxic compound formation.
2Temperature
If LiPF6 electrolyte salt is used, then electrolyte conductivity is maintained, but operating temperature range is restricted
Solution Approach 1:
The patent employs composite electrolyte formulations combining multiple carbonate solvents (EC, DMC, PC) with alternative lithium salts. This composite approach creates an electrolyte system with enhanced thermal stability and expanded operating temperature range compared to single-component electrolytes containing LiPF6.
Solution Approach 2:
The patent modifies the electrolyte composition parameters by adjusting the ratios of carbonate solvents and selecting alternative lithium salts, which changes the thermal and chemical properties of the electrolyte to enable stable operation at elevated temperatures.
3Quantity of substance
If cobalt-containing cathode materials are used, then energy density is improved, but production scalability is limited by cobalt supply
Solution Approach 1:
The patent removes cobalt from the battery system by replacing cobalt-containing cathode materials (such as NCM or LCO) with cobalt-free alternatives like lithium iron phosphate (LFP) or lithium manganese oxide. This extraction eliminates the cobalt supply bottleneck while maintaining battery functionality.
Solution Approach 2:
The patent substitutes expensive, scarce cobalt materials with more abundant, cost-effective alternatives such as iron phosphate or manganese oxide cathodes. This substitution reduces material costs and improves production scalability despite potentially shorter material lifecycles.
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 lithium-ion batteries with improved temperature tolerance, high power performance, and extended cycle life, eliminating the risk of toxic compound generation and enabling scalable, sustainable, and cobalt-free battery production.
Implementation Method 1
The electrolyte may further comprise a lithium salt... The lithium salt concentration may be between 0.1 and 6 M
Implementation Method 2
a solvent mixture comprising at least two carbonate solvents... At least one of the carbonate solvents may be an ethylene carbonate (EC) and/or at least one of the carbonate solvents may comprise a dimethyl carbonate (DMC)
Data Source
AI summary
In the present disclosure, described is an electrolyte for an electrochemical cell comprising a solvent mixture comprising at least two carbonate solvents. Disclosed is also an electrolyte for an electrochemical cell comprising a solvent mixture comprising co-solvent DMC, co-solvent EC, and co-solvent PC, and additives SCN and FEC, wherein the mass % of each of additives SCN and FEC are less than 5%.