Numerical Study on Effect of Ventilation on Fire Characteristics of Lithium-Ion Battery in Energy Storage Cabin

Overview

The study asks how much a designed venting path reduces heat and gas build-up in a storage cabinet during thermal runaway. A Fire Dynamics Simulator (FDS) model of a 1450.7 × 1100 × 1923 mm cabinet with five vertically stacked packs was built, with heat-release and gas-composition inputs from earlier experiments. Runaway was triggered at a critical cell temperature of 180 °C, and a 50 mm grid was chosen after a 100/50/25 mm grid-independence study. A fully closed cabinet and one with an open top were compared over a 100 s window.

In the closed cabinet, local peak temperature exceeded 700 °C and CO and H2 reached around 1000 ppm within 60 s after runaway onset, still rising at the end of the window. H2 rose quickly and formed a growing flammable layer under the roof. The explosion concentration limit of LFP vent gas is cited as 4-15% depending on SOC, with H2 and CO the main contributors, and LFP vent gas has been ignited below the theoretical LEL in confined, non-uniform mixtures.

In the open-top cabinet, an unobstructed buoyancy-driven venting channel formed, and peak temperature and peak CO and H2 concentrations at side monitoring points fell by more than 80% compared with the closed cabinet. Commercial and industrial storage cabinets typically hold 100-215 kWh each.

Limits: the study is simulation-only, battery blocks are homogenised and only a single-cell runaway is modelled; propagation, explosion and vent or door opening details in a real cabinet are not tested. It is useful mainly to show the order-of-magnitude effect of designed venting.

Key points

1. Commercial and industrial storage cabinets typically hold 100-215 kWh each; the modelled cabinet is 1450.7 × 1100 × 1923 mm with five vertically stacked packs.
2. The explosion concentration limit of LFP vent gas is cited as 4-15% depending on SOC, with H2 and CO the main contributors; ignition below the theoretical LEL has been reported in confined, non-uniform mixtures.
3. Runaway was triggered at a critical cell temperature of 180 °C; a 50 mm FDS grid was chosen after a 100/50/25 mm grid-independence study.
4. In the fully closed cabinet, local peak temperature exceeded 700 °C and CO and H2 reached around 1000 ppm within 60 s after runaway onset, still rising at the end of the 100 s window.
5. H2 rose quickly and formed a growing flammable layer under the roof of the closed cabinet.
6. With an open top, peak temperature and peak CO and H2 concentrations at side monitoring points fell by more than 80% compared with the closed cabinet.

Using it in design

• Define a designed, buoyancy-driven vent or relief path at the top of a storage cabinet; in a closed cabinet H2 forms a flammable layer under the roof, so control gas and heat build-up.
• Consider placing gas detectors near the cabinet ceiling, where H2 accumulates, and link detection alarms with ventilation and explosion-protection logic.
• Knowing the homogenised-block, single-cell assumption of this study, use the results as an order-of-magnitude effect and ask for testing and explosion-relief analysis for the real cabinet.

Who should read it

Engineers designing ventilation and explosion protection for commercial and industrial battery cabinets and BESS containers.

Document contents

1. 1. Introduction
2. 2. Model Description (2.1 Physical Model and Locations of Detectors, 2.2 Governing Equations, 2.3 Boundary Conditions, 2.4 Grid Analysis)
3. 3. Results and Analysis (3.1 Fire Spread Behavior in Closed Cabin: fire propagation characteristics, gas dispersion analysis; 3.2 Fire Spread Behavior in Cabin Without Top Cover)
4. 4. Conclusions

Related standards

• NFPA 855
• NFPA 68
• NFPA 69
• UL 9540A

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Publication details

Authors

Wei Lin; Lingcheng Zeng; Junyu Liu; Zhiying Ding

Publisher

Batteries (MDPI AG)

Year

2026

Volume

12

Issue

7

Pages

250

Document language

English

Source type

Scientific

Access

Open licence — downloadable

DOI

10.3390/batteries12070250

Licence

CC BY 4.0 — share with attribution

Licence evidence

www.mdpi.com

Citation