Cylindrical Battery Venting Through Channel Electrode Lugs

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Solution Overview

Problem

Current high energy density cylindrical batteries face challenges in passing safety tests such as hot box and thermal runaway due to difficulties in safely discharging gases during thermal runaway.

Innovation Solution

A safe cylindrical battery design featuring a core assembly with compact and channel full electrode lugs forming a helical structure, integrated with an explosion-proof line on the battery housing, allowing directional gas discharge during thermal runaway.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If high energy density is increased in large cylindrical batteries, then energy storage capacity is improved, but safety performance deteriorates due to difficulty in passing thermal runaway tests

Engineering Contradiction:
Improveenergy storage capacityVSAvoidsafety performance
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The electrode assembly is divided into multiple electrode sheets arranged in a stacked configuration, with each sheet having electrode lugs at opposite ends. This segmentation allows for distributed current collection and creates multiple potential gas discharge paths, improving safety while maintaining high energy density.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Electrode lugs serve as intermediary structures that extend from the electrode sheets toward the battery housing. These lugs create dedicated channels that guide gas discharge away from the electrode stack, acting as a mediator between the thermal runaway source and the battery exterior, thereby improving safety without compromising energy capacity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If electrode structure is simplified to improve manufacturing, then manufacturing ease is improved, but gas discharge capability during thermal runaway deteriorates

Engineering Contradiction:
Improvemanufacturing easeVSAvoidgas accumulation during thermal runaway
Core Design Contradiction:
Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The electrode lugs serve multiple functions: they provide current collection points for electrical connectivity and simultaneously create gas discharge channels during thermal runaway. This multi-functionality allows the same structural element to address both manufacturing simplicity and safety requirements, eliminating gas accumulation without adding separate components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Strength

If battery housing is made more robust to contain pressure, then structural strength is improved, but gas discharge capability deteriorates leading to potential explosion

Engineering Contradiction:
Improvestructural strengthVSAvoidpressure buildup from gas
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

The electrode lugs are pre-positioned and fixed to the electrode sheets before battery assembly, creating predetermined gas discharge paths. This preliminary action ensures that when thermal runaway occurs, gas has already-defined channels to escape through, preventing unpredictable pressure buildup and potential explosion while allowing the housing to maintain its structural strength.

Inventive Principle:
Principle #10Preliminary action

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

The design enables safe directional discharge of gases during thermal runaway, enhancing safety performance by preventing pressure buildup and improving overall safety.

Implementation Method 1

When reaching the explosion-proof valve, the gas breaks through the explosion-proof valve to be discharged out directionally due to the small pressure capacity at the explosion-proof valve

Methodology Applied
Scientific EffectPressure release: Pressure Drop

Data Source

PatentEP4661166A1Safe cylindrical battery
Publication Date: 2025.12.10 SHENZHEN BAK POWER BATTERY CO LTD
  • EP4661166A1 patent drawingFigure 1
  • EP4661166A1 patent drawingFigure 2
  • EP4661166A1 patent drawingFigure 3

AI summary

The present disclosure discloses a safe cylindrical battery, including a battery housing, wherein a core assembly is arranged in the battery housing, and the core assembly includes an electrode sheet (20), a compact full electrode lug (21), and a channel full electrode lug (22); the compact full electrode lug (21) is vertically arranged on one end of the electrode sheet (20); the channel full electrode lug (22) is parallelly arranged on the other end of the electrode sheet (20); the electrode sheet (20), the compact full electrode lug (21), and the channel full electrode lug (22) are of an integral structure; the electrode sheet (20), the compact full electrode lug (21), and channel full electrode lug (22) are wound to form a helical structure; and an explosion-proof line (30) is engraved on one end of the battery housing corresponding to the channel full electrode lug (22). The present disclosure provides a safe cylindrical battery, which can timely and directionally discharge gases in the battery through the channel electrode lug (22) during thermal runaway, so as to improve the safety performance.