High-Density Lithium Battery Electrolyte for Cycle-Life Stability
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Solution Overview
Problem
Increasing the density of the negative electrode in rechargeable lithium batteries leads to a decrease in cycle-life and an increase in battery thickness due to reduced void volumes and increased electrolyte impregnation.
Innovation Solution
A rechargeable lithium battery design with a negative electrode active mass density of at least 1.7 g/cc, utilizing an electrolyte containing a lithium salt, a non-aqueous organic solvent, and an additive represented by Chemical Formula 1, which improves wettability and suppresses lithium dendrite precipitation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the density of the negative electrode is increased, then the energy density of the battery is improved, but the cycle-life of the battery decreases
Solution Approach 1:
The patent changes the chemical composition parameters of the electrolyte by introducing a specific additive (lithium salt of carboxylic acid with fluorinated alkyl group) to enable the negative electrode to operate at higher density (1.7-2.0 g/cc) without compromising cycle-life. This parameter change in electrolyte composition allows the system to achieve high energy density while maintaining reliability.
Solution Approach 2:
The electrolyte additive acts as an intermediary substance that mediates between the high-density negative electrode and the battery system. It forms a protective interface layer that prevents harmful interactions between the dense electrode structure and the electrolyte, thereby preserving cycle-life while enabling high energy density.
2Quantity of substance
If the density of the negative electrode is increased, then the energy density of the battery is improved, but the thickness of the battery increases
Solution Approach 1:
By modifying the electrolyte composition with the fluorinated carboxylic acid lithium salt additive, the patent enables the negative electrode to achieve higher active mass density (1.7-2.0 g/cc). This parameter change allows more active material to be packed into the same volume, increasing energy density without proportionally increasing battery thickness.
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 effectively maintains a high negative electrode density while preventing the increase in battery thickness and maintaining cycle-life, even at higher active mass densities up to 1.8 g/cc.
Implementation Method 1
the electrolyte includes a lithium salt; a non-aqueous organic solvent; and an additive represented by Chemical Formula 1
Implementation Method 2
an additive represented by Chemical Formula 1, which improves wettability and suppresses lithium dendrite precipitation
Implementation Method 3
a positive electrode including a positive electrode active material; a negative electrode including a negative electrode active material, wherein an active mass density of the negative electrode is greater than or equal to about 1.7 g/cc
Implementation Method 4
Electrical energy is produced through oxidation and reduction reactions if (e.g., when) lithium ions are intercalated/deintercalated from the positive electrode and negative electrode
Data Source
AI summary
A rechargeable lithium battery includes a positive electrode including a positive electrode active material; a negative electrode including a negative electrode active material; and an electrolyte, wherein an active mass density of the negative electrode is greater than or equal to about 1.7 g/cc, and the electrolyte includes a lithium salt; a non-aqueous organic solvent; an additive represented by Chemical Formula 1:The description of the chemical formula follows the specification.