Composite Battery Separator for Electrolyte Retention and Ion Transport
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Solution Overview
Problem
Existing secondary batteries face challenges in improving capacity retention rates and ion migration during charging and discharging due to insufficient electrolyte absorption and retention, leading to degraded performance.
Innovation Solution
A separator comprising a first and second porous base film with a pore-structured filler coating between them, enhancing electrolyte absorption and retention, and ion transport.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a conventional separator structure is used, then the mechanical properties are maintained, but the liquid absorption and retention capacities are insufficient
Solution Approach 1:
The separator is constructed as a composite structure combining a porous base film with a coating layer containing pore-structured filler particles. This composite design allows the porous base film to provide mechanical strength while the coating layer with its high-surface-area pore structure enhances liquid absorption and retention capacity through increased electrolyte contact area and capillary action.
Solution Approach 2:
The separator utilizes porous materials at multiple levels: the porous base film provides initial porosity for ion transport, while the pore-structured filler particles in the coating layer introduce additional hierarchical porosity. This multi-scale porous structure significantly increases the surface area available for electrolyte absorption and retention, directly addressing the liquid capacity issue while maintaining structural integrity.
2Speed
If the liquid retention capacity is increased, then the ion transport rate can be improved, but the resistance increases
Solution Approach 1:
The coating layer is applied locally on one or both surfaces of the porous base film, creating a region with enhanced liquid retention properties precisely where electrolyte contact with the separator is most critical. This localized enhancement improves ion transport rates at the electrode-separator interface without requiring the entire separator structure to have increased porosity, thereby avoiding excessive resistance.
Solution Approach 2:
The invention introduces a new dimensional aspect by adding a surface coating layer that extends the functional properties of the separator into an additional spatial dimension. This coating layer with pore-structured filler creates a three-dimensional network of pores on the separator surface, increasing the effective surface area for electrolyte interaction and improving ion transport kinetics without significantly increasing the overall separator thickness or bulk resistance.
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 improves liquid absorption and retention capacities, increases ion transport rates, and extends the service life of secondary batteries by reducing resistance.
Implementation Method 1
The pores are conducive to the physical adsorption of the electrolytic solution and the storage of the electrolytic solution inside the pores
Implementation Method 2
the pore structure can increase the transport rate of active ions, thereby effectively reducing resistance
Implementation Method 3
the first porous base film and the second porous base film encapsulate the coating, thereby further improving the liquid retention capacity of the coating
Data Source
Figure 1~3
Figure 4~6
AI summary
The embodiments of the present application provide a separator, and a secondary battery and an electric device related thereto. The separator comprises a first porous base membrane, a second porous base membrane and a coating, wherein the coating is arranged between the first porous base membrane and the second porous base membrane, and comprises a filler having a pore structure.