Battery Can Seam Welding Structure for Integrated Cap-Collector Joining

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Solution Overview

Problem

The existing manufacturing process of battery cells with cylindrical cans results in reduced energy density due to the need for separate welding masks or jigs, which occupy internal volume, and separate processes for connecting the current collector plate to the can and cap, increasing production time and cost.

Innovation Solution

A welding structure that integrates the connection of the current collector plate to the can and cap into a single process, eliminating the need for separate masks or jigs, and uses the can, current collector plate, and cap as a combined jig and mask to maintain contact and stability during welding, thereby increasing energy density and production efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a separate welding mask or jig is used to maintain the current collector plate in close contact with the cap or sidewall member, then the welding process can be performed, but the internal volume of the can is wasted, reducing energy density

Engineering Contradiction:

Improvewelding process stabilityVSAvoidinternal volume of can

Core Design Contradiction:

ReliabilityVSVolume of moving object

Solution Approach 1:

The cap is designed to serve multiple functions: it seals the can opening and simultaneously acts as a welding mask to maintain close contact between the current collector plate and the sidewall member. This eliminates the need for separate masking components and prevents volume loss while ensuring welding process stability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The welding structure is designed so that the cap itself provides the masking function during welding. The cap's structure naturally maintains the current collector plate in close contact with the sidewall member without requiring external jigs or masks, enabling the system to self-maintain welding conditions.

Inventive Principle:

Principle #25Self-service

2Reliability

If separate welding processes are used for connecting the current collector plate to the cap/sidewall member and for connecting the cap to the sidewall member, then each connection can be optimized, but production time increases and productivity decreases

Engineering Contradiction:

Improveconnection qualityVSAvoidproduction efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent combines the welding of the current collector plate to the sidewall member and the welding of the cap to the sidewall member into a single integrated welding process. The cap serves as a mask that maintains close contact between the current collector plate and sidewall member during this combined welding operation, reducing production time while ensuring reliable connections.

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If a jig or mask is used to maintain close contact during welding, then welding stability is improved, but the device complexity increases due to additional components

Engineering Contradiction:

Improvewelding stabilityVSAvoidnumber of components

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The cap is designed to serve multiple functions: it seals the can opening and simultaneously acts as a welding mask to maintain close contact between the current collector plate and the sidewall member. This eliminates the need for separate masking components and reduces device complexity while ensuring welding process stability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

Inventive Principle:

Principle #25Self-service

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 enhances energy density by optimizing internal volume utilization and reduces production costs and time by integrating the welding processes, improving weld stability and durability.

Implementation Method 1

the radially inner surface of the sidewall, a radially outer surface of the cap, and the peripheral portion of the current collector plate are welded to one another

Methodology Applied

Scientific EffectWelding: Welding

Data Source

PatentUS12603397B2Seam welding structure of battery can, current collecting plate, and cap and battery cell using the same

Publication Date: 2026.04.14 LG ENERGY SOLUTION LTD

AI summary

A battery cell includes: a can with an electrode assembly received therein, in which the can has a bottom member, a sidewall member connected to the bottom member and extending upwardly therefrom in an axial direction, and a cap covering an open end of the can at an axial end opposite to the bottom member. A current collector plate is connected to an electrode tab of the electrode assembly proximate the open end. The current collector plate includes: a central portion electrically connected to the electrode tab and a peripheral portion in electrical contact with a radially inner surface of the sidewall of the can. The peripheral portion is also in contact with an underside of the cap. The radially inner surface of the sidewall member, a radially outer surface of the cap, and the peripheral portion of the current collector plate are all welded to one another.