Li-Ion Battery Anode-Electrolyte Balance for Fast Charge Cycling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium-ion batteries face challenges in achieving high energy density, fast charging and discharging capabilities while maintaining excellent electrochemical performance, particularly in optimizing the relationship between the anode active material and electrolyte components.
Innovation Solution
The electrochemical device comprises an anode with a specific surface area, particle size distribution, and porosity, along with an electrolyte containing fluoroethylene carbonate (FEC) and ethyl propionate, which optimizes the formation of a solid electrolyte interface (SEI) film, improving cycle performance and kinetic performance by enhancing electrolyte infiltration and reducing resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the anode active material has high specific surface area to improve lithium ion migration, then the electrochemical performance is enhanced, but the direct current resistance increases due to excessive electrolyte consumption
Solution Approach 1:
The patent optimizes the specific surface area parameter of the anode active material to a specific range (0.8-2.5 m²/g) to balance lithium ion migration speed and direct current resistance. This parameter optimization ensures fast charging and discharging capabilities while maintaining low resistance and stable cycle performance.
2Reliability
If fluoroethylene carbonate (FEC) content is increased to improve SEI film stability, then cycle performance is enhanced, but the manufacturing cost and electrolyte formulation complexity increase
Solution Approach 1:
The patent specifies the FEC content parameter in the electrolyte within an optimized range to achieve stable SEI film formation and excellent cycle performance. By controlling this chemical composition parameter, the patent simplifies the electrolyte formulation while ensuring reliable electrochemical performance.
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 optimized electrochemical device achieves improved capacity retention rate and reduced direct current resistance, enhancing the overall performance of lithium-ion batteries by facilitating better lithium ion migration and SEI film stability.
Implementation Method 1
optimizes the formation of a solid electrolyte interface (SEI) film
Implementation Method 2
facilitating better lithium ion migration
Implementation Method 3
enhancing electrolyte infiltration and reducing resistance
Data Source
AI summary
An electrochemical device, including a cathode, an anode and an electrolyte. The anode includes an anode current collector and an anode active material disposed on the anode current collector, the electrolyte includes fluoroethylene carbonate, and the electrochemical device meets the following relationship: 17.55≤K1−K2−1.63K32+11.27K3≤20.80, where K1 represents a specific surface area value of the unit mass of the anode active material (in m2/g), and 1.0≤K1≤2.0; K2 represents a content value of the fluoroethylene carbonate required by per Ah capacity (in g/Ah), and 0.05≤K2≤0.25; and K3 represents a weight value of the anode active material required by per Ah capacity (in g/Ah). The electrochemical device of the present application has improved kinetic performance and cycle performance.