Metal-Layer Porous Separator for Heat-Shrink and Dendrite Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing lithium secondary batteries face safety issues due to dendrite growth and thermal shrinkage, leading to short circuits and potential explosions, and existing separators have manufacturing defects and low capacity at low temperatures.
Innovation Solution
A porous separator comprising a layer of plate-type inorganic particles with a binder polymer and a metal layer to inhibit dendrite growth and enhance thermal stability, featuring a tortuous path for ion migration and a low Li diffusion barrier.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a porous organic-inorganic coating layer is formed by coating an excess mixture of inorganic particles and binder polymer on the polyolefin-based porous substrate, then thermal stability is improved, but coating defects occur due to cracks during manufacturing and the layer detaches easily
Solution Approach 1:
The patent changes the particle shape parameter from spherical to plate-type, which fundamentally alters the coating formation mechanism. Plate-type particles create a more flexible and crack-resistant coating structure, eliminating the manufacturing defects while maintaining thermal stability above 100°C.
Solution Approach 2:
The patent creates a composite coating layer using plate-type inorganic particles combined with binder polymer. This composite structure provides both thermal stability and mechanical integrity, preventing coating detachment while maintaining porosity for ion permeability.
2Shape
If the slurry for forming the porous layer is applied to the polyolefin-based porous substrate, then the porous layer is formed, but particle compaction increases during drying resulting in densely packed parts and reduced air permeability
Solution Approach 1:
The patent changes the particle morphology from spherical to plate-type, which prevents excessive compaction during drying. The plate-shaped particles maintain better spacing and orientation, preserving the porous structure and air permeability while still forming a complete coating layer.
3Ease of manufacture
If heavy metal components are mixed in the manufacturing process of the electrode plate and preparation process of raw materials, then the battery can be manufactured, but heavy metals are deposited on the negative electrode surface causing dendrite formation and micro-short circuits
Solution Approach 1:
The patent introduces a porous coating layer as an intermediary barrier between the electrolyte and the electrode surface. This layer prevents heavy metal deposition and dendrite formation while still allowing ion transport, thus blocking the harmful effect without stopping the manufacturing process.
4Ease of manufacture
If polyolefin-based porous substrate is used as separator, then the separator provides basic separation function, but extreme heat shrinkage occurs at temperatures of 100°C or more causing short circuit between electrodes
Solution Approach 1:
The patent creates a composite structure by coating plate-type inorganic particles with binder polymer on the polyolefin substrate. This composite coating layer provides thermal stability above 100°C while the underlying polyolefin substrate maintains ease of manufacture and basic separation functionality.
Solution Approach 2:
The patent changes the thermal properties parameter of the separator by introducing inorganic particles that maintain dimensional stability at high temperatures, preventing the heat shrinkage that occurs with pure polyolefin materials above 100°C.
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 prevents dendrite short circuits and maintains stability at high temperatures, improving battery safety and performance by suppressing dendrite growth and reducing weight and thickness.
Implementation Method 1
The separator effectively prevents dendrite short circuits and maintains stability at high temperatures, improving battery safety and performance by suppressing dendrite growth
Implementation Method 2
a metal layer formed on any one surface of the porous layer... featuring a tortuous path for ion migration and a low Li diffusion barrier
Implementation Method 3
a porous separator comprising a porous layer containing a plurality of plate-type inorganic particles and a first binder polymer positioned on part or all of the surface of the plate-type inorganic particles to connect and fix between the plate-type inorganic particles
Data Source
AI summary
The present invention relates to a porous separator comprising a porous layer containing a plurality of plate-type inorganic particles and a first binder polymer positioned on part or all of the surface of the plate-type inorganic particles to connect and fix between the plate-type inorganic particles; and a metal layer formed on any one surface of the porous layer, and a lithium secondary battery comprising the same.