Separator-Wrapped Electrode Assembly for Thinner Battery Stacks
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Solution Overview
Problem
Conventional electrode assemblies for secondary batteries, which are finished with insulating tape, result in increased thickness, contradicting the trend of reducing battery thickness for higher energy density.
Innovation Solution
The electrode assembly is finished by winding an unfolded winding part of a separator around the outer periphery, with the bonding region positioned on a vertical surface orthogonal to the stacking direction, using a bonding member to secure the separator and electrode plates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If insulating tape is attached to the outer peripheral surface of the electrode assembly, then the electrode assembly is maintained in a rolled and stacked state, but the thickness of the electrode assembly in the stacking direction inevitably increases
Solution Approach 1:
The patent removes the insulating tape from the electrode assembly structure entirely. Instead, the separator itself is extended and wound around the outer peripheral surface to perform both its original function of separating electrodes and the additional function of maintaining the rolled structure, thereby eliminating the need for separate insulating tape and reducing overall thickness.
Solution Approach 2:
The separator is given multiple functions: it continues to separate the positive and negative electrodes while also serving as the structural element that maintains the rolled and stacked state. This multi-functionality eliminates the need for separate insulating tape and reduces the overall thickness of the electrode assembly.
2Reliability
If insulating tape is wound around the electrode assembly, then the electrode assembly structure is secured, but the thickness increases which contradicts the trend of reducing battery thickness to increase energy density
Solution Approach 1:
The patent combines the structural security function previously provided by insulating tape with the separator material. The separator is extended and wound around the electrode assembly, merging the electrode separation function with the structural maintenance function, thereby securing the structure without adding extra components that would increase volume.
Solution Approach 2:
The patent discards the separate insulating tape component and recovers its structural security function by utilizing the separator material itself. The separator is extended beyond the electrode edges and wound around the assembly, allowing it to perform both its original separation function and the structural security function previously requiring separate tape.
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 method allows for the production of a thinner electrode assembly with improved energy density and stable stacking, preventing separation of components and ensuring a flat stacked surface for easy assembly.
Implementation Method 1
the winding end of the separator may be bonded with a bonding member disposed on an outer surface of the winding part that winds the outer periphery of the stacked body
Data Source
AI summary
Proposed is an electrode assembly for a secondary battery, the electrode assembly includes a stacked body including a first electrode plate, a second electrode plate, and a separator interposed between the first electrode plate and the second electrode plate, and an outer periphery of the stacked body may be wound with the separator for exterior finishing. In addition, the present disclosure may include a method of manufacturing an electrode assembly for a secondary battery that is externally finished with a separator.