Segmented Mandrel for Compact Jelly Roll Battery Assembly
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Solution Overview
Problem
Existing battery manufacturing methods face challenges in achieving compactness while maintaining high power output and reliability, as the removal of the mandrel from jelly roll batteries can damage the assembly and result in inefficient use of space, leading to decreased battery capacity and power.
Innovation Solution
A mandrel with a positive portion, a negative portion, and removable portions is used to create a jelly roll electrode assembly, allowing for conductive connections between electrodes and feedthrough pins, which are then secured by heat sealing separators to prevent damage and optimize space usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the mandrel is removed from the core of the jelly roll, then the mandrel can be reused and the assembly process can be simplified, but the jelly roll may be damaged due to pulling the core out
Solution Approach 1:
The mandrel is divided into a retained portion (integrally formed with the jelly roll core) and a removable portion (snap-fit section). This segmentation allows the removable portion to be detached for mandrel reuse while the retained portion remains embedded in the jelly roll to maintain structural integrity and prevent core damage.
2Quantity of substance
If the jelly roll is wrapped tightly to eliminate dead space, then battery capacity and power are increased, but the mandrel removal becomes more difficult and may cause damage
Solution Approach 1:
By segmenting the mandrel into retained and removable portions, the invention enables tight wrapping for maximum capacity while facilitating easy removal of the removable portion without compromising the tightly wrapped jelly roll structure.
Solution Approach 2:
The removable portion is extracted from the mandrel structure, allowing it to be separated from the tightly wrapped jelly roll without requiring loosening of the wrap, thus maintaining maximum density while enabling mandrel reuse.
3Stability of the object's composition
If a non-conductive, non-deformable core is used, then the jelly roll structure is stabilized, but current conduction requires additional conductive tabs which increase complexity
Solution Approach 1:
The mandrel serves multiple functions: it provides the structural core for wrapping, acts as a conductor for current through its conductive material, and enables assembly guidance. This multi-functionality eliminates the need for separate conductive tabs, reducing complexity while maintaining structural stability.
Solution Approach 2:
The invention merges the structural core function and the electrical conduction function into a single mandrel component. The conductive mandrel both stabilizes the jelly roll structure and conducts current, eliminating the need for additional conductive tabs and simplifying the overall device design.
4Reliability
If conductive tabs are added to electrodes to complete the circuit, then electrical connection is achieved, but the number of components and assembly steps increases
Solution Approach 1:
The mandrel combines the structural support function and the electrical conduction function into a single component. By making the mandrel conductive and establishing electrical connection between electrodes through the mandrel, the invention eliminates the need for separate conductive tabs, thereby reducing component count and assembly complexity while ensuring reliable circuit completion.
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 enables the creation of a compact battery with improved reliability and power output by preventing mandrel-induced damage and ensuring efficient use of space within the battery, eliminating the need for extraneous tabs and enhancing the assembly process.
Implementation Method 1
The jelly roll assembly can be secured by heat sealing one or more protruding ends of the one or more separators to each other or to an underlying separator layer
Data Source
AI summary
Provided is an electric storage battery including a jelly roll type electrode assembly having a mandrel. The mandrel includes a positive portion, a negative portion and a removable portion. In some embodiments, the mandrel is planar having two faces with a groove on each of the positive and negative portions. The grooves can be on the same or different faces of the mandrel. The grooves are dimensioned to accommodate a positive and negative feedthrough pin. The electrodes are wrapped around the mandrel using the removable portion to wind the mandrel. Once wrapped, the removable portion can be detached. The positive portion and the negative portion are left in the electrode assembly insulated from each other. The mandrel allows tighter wrapping of the jelly roll assembly, increasing battery miniaturization and also results in electrode assemblies in which after-placement of tabs does not result in burrs or shorting.