Slotted Current Collection Pin for Higher Battery Discharge Current

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Solution Overview

Problem

The small size of the current collection pin in lithium thionyl chloride battery cells results in a small current collection area, limiting the discharge current and application range, while increasing its size compromises the energy density.

Innovation Solution

A current collection pin with a slot body on its outer peripheral surface, such as annular or spiral grooves, increases the contact area with the positive electrode while minimizing the space it occupies, enhancing the current collection area and energy density.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the size of the current collection pin is increased to increase the current collection area, then the current collection area is improved, but the space occupied by the current collection pin inside the battery cell is increased, which negatively impacts the energy density

Engineering Contradiction:
Improvecurrent collection areaVSAvoidspace occupied by current collection pin
Core Design Contradiction:
Area of stationary objectVSVolume of stationary object

Solution Approach 1:

The patent transforms the current collection pin from a simple cylindrical structure to a three-dimensional structure with protrusions extending outward. This dimensional change allows the current collection area to be increased by utilizing the radial dimension, while the overall volume occupied remains constrained by the battery cell geometry. The protrusions create additional contact surfaces with the positive electrode without significantly increasing the axial or radial envelope dimensions.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The current collection pin features localized protrusions that concentrate current collection functionality in specific regions. These protrusions create high-current-density contact zones where they engage with the positive electrode, while other regions of the pin maintain their original geometry. This local enhancement of current collection capability allows increased current area without proportionally increasing the overall pin volume.

Inventive Principle:
Principle #3Local quality

2Volume of stationary object

If the size of the current collection pin is kept small to maintain energy density, then the energy density is improved, but the current collection area becomes small, limiting the discharge current

Engineering Contradiction:
Improvespace occupied by current collection pinVSAvoiddischarge current
Core Design Contradiction:
Volume of stationary objectVSProductivity

Solution Approach 1:

By adding radial protrusions to the current collection pin, the patent creates additional current collection pathways in the radial dimension. This allows the discharge current capability to be enhanced without increasing the axial length or overall radial envelope of the pin, thereby maintaining the compact size needed for high energy density while improving productivity through increased current collection area.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The current collection pin is segmented into multiple protrusion elements that independently contact the positive electrode. This segmentation creates multiple parallel current collection pathways, effectively increasing the total current collection area and discharge current capability while keeping each individual protrusion element compact and the overall pin structure space-efficient.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4636859A1Current collection pin, cover assembly, and battery cell
Publication Date: 2025.10.22 EVE ENERGY CO LTD
  • EP4636859A1 patent drawingFigure 1~2
  • EP4636859A1 patent drawingFigure 3~4
  • EP4636859A1 patent drawingFigure 5~6

AI summary

The present disclosure provides a cover assembly (001) and a battery cell (002), and relates to the technical field of battery cell technologies. The cover assembly (001) includes a current collection pin (011) including a body (111), and a slot body (112) is provided on an outer peripheral surface of the body (111). In the present disclosure, by arranging a slot body (112) on the outer peripheral surface of the body (111), a space occupied by the current collection pin (011) inside the battery cell (002) can be controlled, and an outer surface area of the current collection pin (011) can be increased, thereby increasing a contact area between the current collection pin (011) and a positive electrode (025), and increasing a current collection area of the current collection pin (011).