Electrode-Separator Composite Manufacturing via Direct Polymer Coating
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Solution Overview
Problem
Current lithium secondary battery manufacturing processes are inefficient and lack thermal safety due to high thermal shrinkage of polyolefin-based separators, leading to potential short circuits and instability at high temperatures.
Innovation Solution
A method of directly coating a polymer solution containing polymer particles on an electrode to form a porous separator, eliminating the need for separate separator manufacturing and enhancing thermal safety by controlling pore uniformity and tortuosity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a polyolefin-based separator is used to prevent short circuits, then electrical insulation is improved, but thermal safety deteriorates due to high thermal shrinkage at high temperatures
Solution Approach 1:
The patent applies composite materials by combining polyolefin base material with silane-modified polymers that contain crosslinkable functional groups. This composite structure maintains the electrical insulation properties of polyolefin while adding thermal stability through crosslinking, preventing thermal shrinkage at high temperatures. The silane-modified polymer forms a three-dimensional crosslinked network that restricts thermal contraction.
Solution Approach 2:
The patent changes the physical and chemical parameters of the separator material by introducing silane-modified polymers with crosslinkable functional groups. The crosslinking degree and molecular structure are adjusted to optimize both electrical insulation and thermal resistance properties, transforming the material from thermoplastic to thermosetting characteristics.
2Object-affected harmful factors
If a porous coating layer containing inorganic particles is formed on a polyolefin-based separator to enhance thermal safety, then thermal shrinkage resistance is improved, but manufacturing complexity increases due to separate manufacturing processes
Solution Approach 1:
The patent merges the separator base layer and the thermal protective coating layer into a single integrated structure. The silane-modified polymer is applied directly to the polyolefin separator and crosslinked in situ, forming a unified composite separator that combines electrical insulation and thermal protection functions, eliminating the need for separate coating and assembly processes.
Solution Approach 2:
The silane-modified polymer coating serves multiple functions simultaneously: it provides thermal shrinkage resistance through crosslinking, maintains porosity for ion transport, and adheres to the polyolefin substrate. This multi-functional material replaces the need for separate specialized components.
3Manufacturing precision
If a porous separator is manufactured by separate processes and then assembled with electrodes, then separator quality is controlled, but productivity decreases due to multiple manufacturing steps
Solution Approach 1:
The silane-modified polymer coating is applied to the separator before final assembly with electrodes. The crosslinking process is initiated in advance during the coating stage, preparing the thermal protective layer before the separator is integrated into the battery structure, thereby streamlining the overall manufacturing sequence.
Solution Approach 2:
The patent combines separator manufacturing and coating application into a single integrated process step. The silane-modified polymer is coated and crosslinked on the separator in one operation, eliminating the need for separate coating, drying, and assembly steps, thereby improving productivity while maintaining quality.
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
This approach simplifies the manufacturing process, reduces costs and time, and improves thermal safety by preventing internal short circuits and maintaining battery performance through manganese ion capture, while maintaining mechanical stability and reducing internal resistance.
Implementation Method 1
drying to form an electrode, coating a polymer solution containing polymer particles on at least one surface of the electrode to form a separator coating layer, and drying the separator coating layer to form a porous separator
Implementation Method 2
controlling pore uniformity and tortuosity
Data Source
AI summary
Disclosed is a method of manufacturing an electrode-separator composite: including (S1) coating an electrode active material slurry on at least one surface of an electrode current collector and drying to form an electrode, (S2) coating a polymer solution containing polymer particles on at least one surface of the electrode to form a separator coating layer, and (S3) drying the separator coating layer to form a porous separator, and an electrode-separator composite manufactured by the manufacturing method and a lithium secondary battery comprising the same.According to the present disclosure, a porous separator is manufactured by coating polymer particles on an electrode, thereby effectively controlling the uniformity and tortuosity of the pores, a porous separator is manufactured by directly coating a polymer solution on an electrode without separately manufacturing a separator, thereby saving the process costs and time, and further, when a functional group able to capture manganese is attached to the surface of polymer particles constituting a separator, deterioration in battery performance may be prevented through removal of manganese ions that may be deposited on an anode during operation of a battery.