Electrochemical Device Anode Interface Stabilization
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Solution Overview
Problem
Lithium-ion batteries face challenges in maintaining high cycle performance and storage performance due to the formation of pinholes and pits in the active substance layer caused by bubbles in aqueous slurry compositions, leading to deterioration in performance over cycles.
Innovation Solution
An electrochemical device is developed with a phosphorus- and oxygen-containing compound in the electrolyte and an anode mixture layer featuring specific characteristics such as a carbon material with controlled lithium precipitation, auxiliary agents, and optimized structural parameters to stabilize the anode interface, thereby reducing lithium precipitation area and improving cycle and high-temperature storage performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If aqueous slurry compositions are used to reduce environmental impact, then environmental friendliness is improved, but pinholes and pits form in the active substance layer due to bubbles, worsening manufacturing precision and device reliability
Solution Approach 1:
The patent extracts and removes bubbles from the aqueous slurry composition through a vacuum treatment process before coating. This eliminates the harmful bubbles that would otherwise create pinholes and pits in the active substance layer, allowing the use of environmentally friendly aqueous slurries without compromising layer quality.
Solution Approach 2:
The patent applies preliminary vacuum treatment to the aqueous slurry composition before the coating process. This preliminary removal of bubbles prevents the formation of defects during subsequent coating and drying operations, ensuring high manufacturing precision from the outset.
2Device complexity
If conventional electrolytes and anode structures are used, then device complexity is low, but lithium precipitation forms on the anode surface during cycling, worsening reliability and performance
Solution Approach 1:
The patent modifies the electrolyte composition by adding specific additives (fluorinated cyclic carbonate and chain carbonate in controlled ratios) and adjusts the anode structure parameters (porosity, thickness, carbon material composition). These parameter changes prevent lithium precipitation while maintaining device functionality and improving cycle reliability.
Solution Approach 2:
The patent uses a composite anode structure combining carbon materials with specific porosity and surface properties, along with a composite electrolyte system containing multiple components working synergistically. This composite approach stabilizes the solid electrolyte interface and prevents lithium dendrite formation, enhancing reliability without excessive complexity.
3Ease of manufacture
If simple anode structures are used, then ease of manufacture is high, but high-temperature storage performance deteriorates due to interface instability, worsening reliability
Solution Approach 1:
The patent optimizes anode parameters including porosity (30-70%), thickness, and carbon material composition to achieve stable interface formation during initial cycling. This creates a protective solid electrolyte interface that prevents degradation during high-temperature storage while maintaining ease of manufacture through conventional coating and drying processes.
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 stabilizes the anode interface, reducing lithium precipitation and enhancing cycle and storage performance, leading to improved safety and performance retention in lithium-ion batteries.
Implementation Method 1
the electrolyte includes a phosphorus- and oxygen-containing compound, the anode includes an anode current collector and an anode mixture layer formed on the anode current collector, and after 100 charge and discharge cycles, an area of lithium precipitation of a surface of the anode mixture layer is 2% or below based on a total surface area of the anode mixture layer
Data Source
AI summary
An electrochemical device, including a cathode; an electrolyte; and an anode. The electrolyte includes a phosphorus and oxygen containing compound, and the anode includes an anode current collector and an anode mixture layer formed on the anode current collector, and after 100 charge and discharge cycles, an area of lithium precipitation of a surface of the anode mixture layer is 2% or below based on a total surface area of the anode mixture layer. The electrochemical device has improved cycle performance, storage performance and safety performance.