Thin-Wall Button Battery Structure for Higher Electrolyte Volume
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Solution Overview
Problem
Conventional button batteries have limited volume, resulting in low energy density due to thick shells and insulating layers, which restrict the increase in battery energy density within a small form factor.
Innovation Solution
A battery structure with a reduced wall thickness, featuring a housing, cap assembly, and electrode assembly where an insulating layer is placed between the cover body and pressing plate, allowing for increased electrolyte volume and energy density through a simplified design and efficient sealing mechanism.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional multi-layered side walls are used in button batteries, then structural strength and sealing are improved, but wall thickness increases, reducing the accommodating cavity volume and battery energy density
Solution Approach 1:
The battery structure is divided into separate components: the housing forms the side wall, while the cap assembly (comprising cover body, pressing plate, and insulating layer) forms the top and bottom seals. This segmentation allows each component to be optimized independently, enabling thin-walled construction without compromising overall structural integrity.
Solution Approach 2:
The cap assembly integrates multiple functions into a single assembled unit: the cover body provides structural closure, the pressing plate applies compression force, and the insulating layer provides electrical isolation. This merging of functions into integrated components reduces the need for separate thick protective layers.
2Reliability
If thick sealing insulating layers are used in conventional button batteries, then sealing reliability is improved, but the volume available for electrolyte is reduced, lowering battery energy density
Solution Approach 1:
The insulating layer is designed as a thin film component within the cap assembly rather than a thick rigid layer. This thin-film approach provides sufficient electrical isolation and sealing functionality while occupying minimal space, thereby maximizing the electrolyte volume within the accommodating cavity.
Solution Approach 2:
The cap assembly is pre-assembled with the insulating layer positioned between the cover body and pressing plate before being connected to the housing. This preliminary assembly ensures proper sealing and insulation are established in advance, allowing the housing walls to be minimized without compromising sealing reliability.
3Strength
If the housing and cap assembly are connected with thick walls for structural integrity, then mechanical strength is improved, but the overall battery volume is consumed, reducing energy density
Solution Approach 1:
The housing wall thickness is optimized to a specific thin range (0.1-0.25mm) that provides sufficient mechanical strength while maximizing internal volume. This parameter optimization allows the structure to maintain integrity without the excessive wall thickness of conventional designs, directly improving energy density.
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 reduced wall thickness increases the volume of the accommodating cavity, leading to higher electrolyte filling amounts and enhanced battery energy density, with improved sealing and manufacturing efficiency.
Implementation Method 1
assembling, heating, and cooling the cover body and the pressing plate, to form the cap assembly
Implementation Method 2
the upper end surface is welded to the lower end surface, to implement a sealing connection
Data Source
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AI summary
The present invention relates to a battery structure and a preparation method therefor. The battery structure includes: a housing (10), a cap assembly (20), and an electrode assembly, where an accommodating cavity is provided in the housing, the electrode assembly is placed in the accommodating cavity, the accommodating cavity is further filled with electrolyte, two electrodes are arranged on the electrode assembly, one of the two electrodes is electrically connected to the cap assembly, and the other of the two electrodes is electrically connected to the housing, and the housing is connected to a side wall after being combined with the cap assembly. In the present invention, a wall thickness is reduced, which may effectively increase a volume of the accommodating cavity, to increase a filling amount of electrolyte, thereby effectively increasing a battery energy density.