Separator Coating Anisotropy for Transverse Strength
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional lithium ion battery separators lack sufficient strength in the transverse direction during the winding process, leading to potential deformation and tear, which compromises the durability and reliability of the energy storage device.
Innovation Solution
A separator with a uniaxially drawn substrate and a coating layer having an anisotropic structure oriented in a direction different from the drawing direction, providing enhanced tensile strength in the transverse direction through the use of a composite material containing oriented fibers, fillers, and a binder, thereby reinforcing the substrate and preventing deformation and tear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If multilayering the separator is implemented to improve strength, then the strength is improved, but the device complexity increases
Solution Approach 1:
Instead of changing the structural configuration to multiple layers, the invention modifies the thickness parameter of a single-layer separator. By controlling the thickness distribution across the transverse direction, the separator achieves enhanced strength without increasing structural complexity. This parameter-based approach avoids the complications of multilayer construction while meeting strength requirements.
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 anisotropic structure of the coating layer effectively balances tensile strength in both the machine direction and transverse direction, significantly improving the durability and reliability of the energy storage device by preventing deformation and tear during production and use.
Implementation Method 1
the coating layer has an anisotropic structure with orientation in a direction different from a drawing direction of the substrate
Implementation Method 2
the resin of the separator is typically oriented in its longitudinal direction agreeing with its drawing direction. The separator thus has relatively large strength in an MD direction agreeing with the drawing direction
Data Source
AI summary
An energy storage device includes a positive electrode provided with a positive composite layer containing a positive active material, a negative electrode provided with a negative composite layer containing a negative active material, and a separator partitioning between the positive electrode and the negative electrode, wherein the separator includes a substrate uniaxially drawn into a sheet shape and a coating layer coating at least one of surfaces of the substrate, and the coating layer has an anisotropic structure with orientation in a direction different from a drawing direction of the substrate.