Battery Cell Electrolyte Salt Composition for Thin Copper Foils
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium-ion batteries face challenges in achieving both high energy density and safety performance, particularly due to the reduction in thickness of copper foils used as current collectors, which affects heat dissipation and internal resistance.
Innovation Solution
Incorporation of a first electrolyte salt, such as lithium bis(fluorosulfonyl)imide, into the electrolyte solution, along with specific ratios and combinations of other electrolyte salts and additives, to enhance ion dissociation and thermal stability, while managing corrosion and reaction risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the thickness of copper foil current collector is reduced to improve energy density, then energy density increases, but heat dissipation performance deteriorates and internal resistance increases
Solution Approach 1:
The patent changes the chemical composition parameters of the electrolyte by introducing a specific additive containing fluorine atoms and C1-C3 alkyl groups. This chemical parameter change enables the electrolyte to form protective films on the copper foil surface, improving heat resistance without requiring changes to the physical dimensions (thickness) of the current collector, thus resolving the contradiction between energy density and heat dissipation performance
Solution Approach 2:
The patent introduces an electrolyte additive as an intermediary substance that mediates between the copper foil current collector and the electrolyte solution. This additive forms a protective interface layer on the copper foil surface, which improves heat resistance and prevents direct harmful interactions, allowing thin copper foil to be used without compromising safety or performance
2Quantity of substance
If the thickness of copper foil current collector is reduced to improve energy density, then energy density increases, but internal resistance increases
Solution Approach 1:
The patent modifies the electrolyte composition by adding specific chemical compounds with fluorine and alkyl groups, changing the chemical parameters of the electrolyte system. This enables the formation of protective films on the copper foil that reduce internal resistance through improved interfacial contact and electron transport, allowing thin current collectors to maintain low internal resistance
3Ease of manufacture
If conventional electrolyte composition is used to maintain stability, then manufacturing simplicity is maintained, but energy density and safety performance cannot be improved
Solution Approach 1:
The patent optimizes the concentration parameter of the electrolyte additive within a specific range (0.1-5 wt%) to achieve improved safety performance while maintaining manufacturing simplicity. This controlled parameter change allows the use of conventional manufacturing processes with only minor adjustments to electrolyte formulation
Solution Approach 2:
The patent creates a composite electrolyte system by combining conventional electrolyte components with a specially designed additive containing fluorine atoms and C1-C3 alkyl groups. This composite electrolyte maintains the simplicity of conventional electrolyte preparation while adding enhanced safety and performance properties through the synergistic combination of materials
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 improves energy density and safety performance by optimizing the electrolyte composition, reducing adverse effects on current collectors, and enhancing heat resistance and power output.
Implementation Method 1
The first electrolyte salt containing the R2 group has relatively large ion dissociation energy, and more active R1 ions can be dissociated
Implementation Method 2
the first electrolyte salt containing the R2 group has relatively high thermal stability, to help to improve overall heat resistance of the electrolyte solution
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
Embodiments of this application provide a battery cell, a battery, and a power consuming device. The battery cell includes: an electrode assembly, where the electrode assembly includes a positive electrode plate and a negative electrode plate; and an electrolyte solution, where the electrolyte solution includes a first electrolyte salt, and a molecular formula of the first electrolyte salt is: where R1 is one of Li, Na, K, Mg, and Al, R2 is at least one of element O, element S, element F, and C1-C3 alkyl or C1-C3 alkyl substituted with element F, and based on 100 parts by weight of the electrolyte solution, content W1 of the first electrolyte salt ranges from 2 parts by weight to 20 parts by weight. According to the technical solution of this application, energy density and safety performance of the battery can be improved.