Propionate Electrolyte and Carbon Anode Tuning in Lithium Secondary Batteries
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Solution Overview
Problem
Lithium secondary batteries face degradation issues affecting their performance and lifespan due to electrolyte solutions and active materials, leading to reduced capacity retention and increased resistance during repeated charging and discharging.
Innovation Solution
A lithium secondary battery design featuring carbon-based active material particles with a specific Brunauer-Emmett-Teller (BET) specific surface area of 3.0 to 5.0 m2/g and average particle diameter of 5 to 7.5 μm, combined with a cathode using lithium-transition metal oxide particles of 2.5 to 3.5 μm and a non-aqueous electrolyte solution containing a propionate-based organic solvent with 55 vol % or more, along with maleic acid to stabilize the cathode slurry viscosity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional electrolyte solutions and active materials are used, then battery assembly is straightforward, but capacity retention deteriorates and resistance increases during repeated charging and discharging
Solution Approach 1:
The patent changes the chemical composition parameters of the electrolyte solution by incorporating a propionate-based organic solvent (55-80 vol%) combined with carbonate-based solvents. This parameter change in electrolyte composition reduces degradation during charging/discharging cycles, improving both capacity retention and lifespan without requiring fundamental redesign of the battery structure.
2Power
If carbon-based active material particles with optimized BET specific surface area and particle diameter are used, then power properties are improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent specifies precise parameter ranges for carbon-based active material particles: BET specific surface area of 3.0-5.0 m2/g and average particle diameter of 5-7.5 μm. By optimizing these physical parameters within defined ranges, the invention achieves improved power properties while maintaining feasible manufacturing precision through controlled particle engineering processes.
3Power
If propionate-based organic solvent content is increased to 55 vol % or more, then power properties are enhanced, but electrolyte solution stability may deteriorate
Solution Approach 1:
The patent creates a composite electrolyte solution system by combining propionate-based organic solvent (55-80 vol%) with carbonate-based solvents. This composite approach leverages the high ionic conductivity and power enhancement benefits of propionate-based solvents while the carbonate-based components provide structural stability and compositional balance, resolving the contradiction between power enhancement and stability maintenance.
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
This configuration enhances the power and lifespan properties of lithium secondary batteries by reducing resistance and improving capacity retention, leading to high-power and high-capacity performance.
Implementation Method 1
a non-aqueous electrolyte solution including a non-aqueous organic solvent that contains a propionate-based organic solvent and a lithium salt
Implementation Method 2
an anode including an anode active material that contains carbon-based active material particles including carbon
Implementation Method 3
The cathode active material layer may include lithium-transition metal oxide particles having an average particle diameter (D50) of 2.5 μm to 3.5 um
Data Source
AI summary
Lithium secondary batteries are disclosed. In an embodiment, a lithium secondary battery includes an anode including an anode active material that includes carbon-based active material particles including carbon, the carbon-based active material particles having a Brunauer-Emmett-Teller (BET) specific surface area of 3.0 m2/g to 5.0 m2/g and an average particle diameter (D50) of 5μm to 7.5 μm, a cathode facing the anode, and a non-aqueous electrolyte solution including a non-aqueous organic solvent that includes a propionate-based organic solvent including propionate and a lithium salt. A content of the propionate-based organic solvent relative to a total volume of the non-aqueous organic solvent is 55 vol % or more.