Cylindrical Lithium Battery Tab Structure for Fast Filling and Venting
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Solution Overview
Problem
Existing cylindrical lithium-ion battery designs face challenges in liquid injection and formation efficiency, discharge capability, and safety due to structural limitations that affect lead-out current and increase the risk of safety hazards from internal gas generation.
Innovation Solution
A cylindrical lithium battery design featuring a multi-tab cathode lead-out structure and full-tab anode lead-out structure, with a central liquid injection hole and safety valve, and a current collector support that ensures a large welding area and facilitates assembly, addressing the inefficiencies and safety concerns of prior designs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a full-tab lead-out structure is used to reduce heat generation, then heat dissipation is improved, but liquid injection and formation operation become difficult
Solution Approach 1:
The battery cell structure is segmented into distinct functional zones: the upper portion contains the full-tab lead-out structure for heat dissipation, while the lower portion maintains a traditional structure with accessible liquid injection holes for formation operation. This segmentation allows both requirements to coexist without conflict.
2Power
If a current collector tray with annular groove is used to weld tabs, then lead-out current is improved, but welding area between inner and outer rings is reduced
Solution Approach 1:
The invention extracts the welding function from the complex annular groove structure and concentrates it onto the tab surface itself. The tab is designed with an integrated welding surface that directly contacts the current collector tray, eliminating the need for separate annular grooves and maximizing the welding area.
3Area of stationary object
If a tray sleeve is added to increase welding diameter, then welding area is improved, but circumferential welding area is reduced and welding difficulty increases
Solution Approach 1:
The invention merges the current collector tray and tab into a direct welding assembly, eliminating the need for a separate tray sleeve component. The tab extends directly onto the current collector tray surface, creating a large welding area without adding structural complexity or reducing circumferential welding capability.
4Reliability
If explosion-relief valve and liquid injection hole are positioned on opposite sides, then safety is improved, but fabrication and installation process becomes complicated
Solution Approach 1:
The battery cell cover is designed with multi-functionality: it simultaneously serves as the mounting surface for both the explosion-relief valve and the liquid injection hole. Both components are positioned on the same cover plate, allowing unified fabrication and installation processes while maintaining safety performance.
5Reliability
If liquid injection hole is positioned at lateral side of cover plate, then safety valve can be on opposite side, but liquid injection speed is affected
Solution Approach 1:
The invention changes the positioning dimension of the liquid injection hole from the lateral side to the central axis of the battery cell. This dimensional change allows the liquid injection hole to be positioned at the center of the cover plate, maximizing injection speed while the explosion-relief valve is positioned radially outward on the same cover, maintaining safety functionality.
Data Source
AI summary
A cylindrical lithium battery and a producing method thereof are disclosed. The lithium battery includes a shell, a battery cell, a cathode battery cover-plate assembly and an anode battery cover-plate assembly. A cathode foil and an anode foil are separated by a separator and wind into a cylindrical battery cell. The cathode is of a multi-tab structure and the anode is of a full-tab structure. A sealing body is fixed on the cathode battery cover plate in a surrounding manner, and a safety valve is provided at the middle of the cathode battery cover plate. The anode battery cover-plate assembly includes a current collector, an anode battery cover plate and a current collector support. The current collector body is fixedly connected to the upper portion of the current collector support and is electrically connected to the anode battery cover plate via a current collector connecting portion.