Battery Shell Top Cover Structure for Low-Protrusion Side Welding

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Solution Overview

Problem

The existing side welding process for battery top covers creates high welding protrusions that cause friction between adjacent modules, leading to structural instability and low voltage resistance in large battery cells.

Innovation Solution

A battery shell design with a welding gap between the battery shell body and top cover body, limiting the welding protrusion to 0.1 mm, and using a side welding technique to enhance connection strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If side welding process is used to seal the top cover, then welding strength is improved, but welding protrusion increases causing friction between adjacent modules

Engineering Contradiction:

Improvewelding strengthVSAvoidwelding protrusion causing friction

Core Design Contradiction:

StrengthVSObject-generated harmful factors

Solution Approach 1:

The top cover is divided into a first area and a second area, with the welding process specifically applied to the first area. This segmentation allows the welding protrusion to be localized and controlled, preventing it from extending into the second area where it would cause friction with adjacent modules.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different areas of the top cover are given different functional qualities: the first area is designed for welding with appropriate protrusion characteristics, while the second area is designed to be flush or recessed to minimize friction. This local differentiation resolves the contradiction by optimizing each area for its specific function.

Inventive Principle:

Principle #3Local quality

2Strength

If welding protrusion is increased to enhance welding strength, then connection strength is improved, but friction between adjacent modules increases

Engineering Contradiction:

Improveconnection strengthVSAvoidfriction between adjacent modules

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The top cover surface is segmented into functional zones: a first area where welding protrusion is permitted and even encouraged for strong connection, and a second area where the surface is controlled to prevent friction. This spatial segmentation allows both high connection strength and low friction to coexist.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The division into first and second areas acts as an intermediary mechanism that mediates between the conflicting requirements of welding protrusion (for strength) and surface flatness (for friction reduction). The first area serves as the welding zone with appropriate protrusion, while the second area serves as the friction-reduction zone.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS20260031447A1Battery shell, single battery cell, and battery pack

Publication Date: 2026.01.29 EVE POWER CO LTD

AI summary

A battery shell, a single battery cell, and a battery pack are provided. The battery shell includes: a battery shell body, wherein the battery shell body is provided with an opening; and a top cover body, wherein the top cover body is covered on the battery shell body at the opening, an end surface, facing the top cover body, of the battery shell body is defined as an upper end surface, and the upper end surface is divided into a first area and a second area located at an outer side of the first area towards an edge; the top cover body is assembled on the first area of the battery shell body, and a welding gap is formed between the second area of the battery shell body and an outer edge of the top cover body.