Cylindrical Cell Current Collector Welding for Higher Energy Density
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Solution Overview
Problem
The energy density per unit volume of cylindrical secondary cells is limited by gaps between the wound electrode assembly and end caps, which restricts their performance as a main power source for electricity-consumption devices.
Innovation Solution
A current collector is welded to the peripheral side surfaces of both the end cap and housing in an energy storage device, enhancing the connection strength and reducing gaps, thereby improving energy density and structural integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the current collector is welded to the peripheral side surfaces of the end cap and housing, then the connection strength among these components is improved, but the manufacturing complexity and welding precision requirements increase
Solution Approach 1:
The current collector is divided into two functional portions: a main body portion that connects to the electrode assembly, and a welding portion that extends to the peripheral side surface for welding to the end cap and housing. This segmentation allows the welding operation to be performed on a dedicated welding portion rather than the entire current collector, simplifying the welding process while maintaining connection strength.
Solution Approach 2:
The welding portion is pre-formed as an integral part of the current collector before assembly. This preliminary formation of the welding portion ensures proper positioning and alignment during the welding process, reducing the need for complex positioning fixtures and procedures while ensuring consistent weld quality.
2Manufacturing precision
If the welding portion protrudes from the end cap and housing by controlled widths L1 and L2, then the welding precision and connection reliability are improved, but the manufacturing complexity increases
Solution Approach 1:
The patent specifies precise parameter ranges for the protrusion widths L1 and L2 of the welding portion. By controlling these dimensional parameters within specific ranges, the welding process achieves optimal precision and reliability. The parameter control is implemented through precision forming processes that ensure consistent protrusion dimensions across production batches.
Solution Approach 2:
The welding portion acts as an intermediary element between the current collector main body and the end cap/housing. This intermediary structure facilitates the welding connection by providing a dedicated interface with controlled geometry, simplifying the assembly process while ensuring precise alignment and consistent weld quality.
3Stability of the object's composition
If the outer peripheral side surface of the main body is flush with or protrudes from the end cap and housing, then the structural integrity is improved, but the manufacturing precision requirements increase
Solution Approach 1:
The patent allows for asymmetric configurations where the main body's outer peripheral side surface can be either flush with or protrude from the end cap and housing. This asymmetric design flexibility enables optimization of structural integrity for different application requirements. The welding portion compensates for any asymmetry by providing a standardized welding interface, maintaining connection reliability across different configurations.
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 enhanced connection between the end cap, current collector, and housing increases the energy storage device's energy density and structural strength, providing stable power for electricity-consumption devices.
Implementation Method 1
A current collector of the energy storage device is welded to a peripheral side surface of an end cap and a peripheral side surface of a housing
Data Source
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AI summary
This disclosure provides an energy storage device, a welding method for an energy storage device, and an electricity-consumption device. The energy storage device includes an end cap, a housing, and a current collector arranged between the end cap and the housing. The current collector includes a main body and a welding portion, and the main body and the welding portion are integrally formed. The main body has a first surface and a second surface facing away from the first surface. The end cap is connected to the first surface of the main body, the housing is connected to the second surface of the main body, and the welding portion is connected to an outer peripheral side surface of the end cap, an outer peripheral side surface of the housing, and an outer peripheral side surface of the main body. In the energy storage device in the disclosure, the current collector is arranged between the end cap and the housing, and is welded to both a peripheral side surface of the end cap and a peripheral side surface of the housing, and thus the welding region between the end cap and the current collector may be enlarged, thereby improving a current-flow through capability between the end cap and the current collector and accordingly improving a strength of connection among the end cap, the current collector, and the housing.