Coumarin-Coated Battery Separator for Radical and Metal Ion Capture
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium secondary batteries with high transition metal content in anodes generate radicals or elute transition metal ions during charging and discharging, leading to performance degradation and capacity loss due to unwanted by-products and impurity formation on the cathode.
Innovation Solution
A separator for electrochemical devices featuring a porous polymer substrate with a porous coating layer containing surface-modified inorganic particles bound with coumarin or its derivatives, which scavenge radicals and adsorb transition metal ions, preventing performance degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If high transition metal content anodes are used to achieve higher energy density, then capacity and energy density are improved, but radicals and transition metal ions are generated during charging and discharging, leading to performance degradation and capacity loss
Solution Approach 1:
A porous coating layer is introduced as an intermediary between the anode and cathode. This coating layer contains inorganic particles (such as Al2O3, SiO2, TiO2, or ZnO) that are surface-modified with coumarin compounds. The coating layer acts as a mediator to scavenge radicals and adsorb transition metal ions generated during charging and discharging, preventing these harmful substances from causing performance degradation while allowing the high transition metal content anode to maintain its high energy density
Solution Approach 2:
The coating layer is designed with a porous structure having a specific pore volume (0.3-0.8 mL/g) and pore diameter (2-10 nm). This porous structure allows the coating layer to effectively trap and retain radicals and transition metal ions generated during electrochemical reactions, while still permitting ion transport necessary for battery operation. The porous structure provides sufficient surface area for radical scavenging and ion adsorption activities
2Reliability
If a porous coating layer with surface-modified inorganic particles is applied to scavenge radicals and adsorb transition metal ions, then performance degradation is prevented, but the device complexity increases
Solution Approach 1:
The coating layer is constructed as a composite material system combining inorganic particles (Al2O3, SiO2, TiO2, or ZnO) with coumarin compounds. The inorganic particles provide structural support and surface area, while the coumarin surface modification provides radical scavenging and ion adsorption functionality. This composite structure achieves high performance stability through synergistic effects while maintaining a relatively simple overall design that can be integrated into existing battery architectures
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 separator effectively removes radicals and transition metal ions, enhancing the lifespan and output of lithium secondary batteries by preventing capacity degradation and reducing gas generation from side reactions.
Implementation Method 1
The compounds may function to remove radicals generated during charging and discharging of the electrochemical device through the 7-position of the coumarin
Implementation Method 2
The compounds may contain a functional group capable of adsorbing transition metal ions generated during the charging and discharging of the electrochemical device
Data Source
AI summary
The present invention provides a separator for an electrochemical device includes a porous polymer substrate, and a porous coating layer formed on at least one surface of the porous polymer substrate, wherein the porous coating layer includes a polymer binder, and inorganic particles whose surface is modified with one or more compounds selected from the group consisting of coumarin and a derivative thereof.