MEGEL MG-650-EV — Aerogel Felt Thermal Runaway Barrier for EV Battery Packs

Overview

MEGEL MG-650-EV is the EV battery thermal-runaway-barrier specification within the MEGEL silica aerogel felt range — a thin-section (1.5–3 mm) felt engineered for installation between lithium-ion battery cells, modules, or pack-to-pack-housing interfaces to delay heat propagation during a thermal runaway event. The reinforcement is a mica/glass laminate combining the dimensional stability of high-temperature mica paper with the tensile strength of woven glass fibre, qualifying the felt for the UL 9540A unit-level passing test that governs propagation-resistant battery design.

The application case is the lithium-ion thermal runaway event — a cascading failure where one cell vents combustible electrolyte vapour and reaches surface temperatures of 700–1000°C+ within seconds. Adjacent cells in an unprotected pack reach their own thermal runaway threshold within 10–30 seconds, leading to cascade failure of the full pack. Inserting MG-650-EV between cells or between modules absorbs and delays the propagation heat flux, buying the battery management system time to disconnect the failed cell and crew time to evacuate from automotive and stationary-storage applications.

Two procurement-relevant differentiators target the EV pack design context:

1. Thin-section format. MEGEL MG-650-EV is manufactured at 1.5, 2.0, 2.5, and 3.0 mm thicknesses — sub-millimetre tolerances allowing direct insertion into module cell stacks without redesigning pack volume budgets. The thermal conductivity at 25°C (0.020–0.025 W/(m·K)) and at 1000°C runaway conditions delivers the propagation-delay envelope automotive OEMs require under GB 38031 (China) and equivalent ECE R100 (Europe) regulations.

2. Non-flammable, low smoke. Unlike polymer-foam or ceramic-paper alternatives that emit corrosive smoke during runaway, MEGEL MG-650-EV is silica aerogel — chemically inert, non-combustible (GB 8624 Class A), and zero-smoke under runaway conditions. Vehicle cabin and battery-room atmosphere quality during a runaway event is materially improved compared to polymer barrier alternatives.

The product is supplied to multiple Chinese OEMs in 800V architecture battery packs and to global stationary energy storage system integrators for grid-scale BESS deployments.

Technical Specifications

Applications

Cell-to-Cell Barrier in Lithium-Ion Battery Modules

MG-650-EV at 1.5–2.0 mm is the cell-spacer layer in prismatic and pouch-cell module designs from 800V automotive architectures. Inserted between each cell, the felt absorbs vent-jet heat flux and delays cell-to-cell propagation by 5–15 minutes depending on cell chemistry, format, and SOC at the time of failure. Combined with cell-level burst-disc venting and module-level pressure-relief design, the barrier converts a pack-level runaway into a single-cell failure with retained vehicle limp-home capability in many cases.

Module-to-Module Barrier in Pack Assemblies

In multi-module pack assemblies for commercial vehicles, marine propulsion, and stationary storage, MG-650-EV at 2.5–3.0 mm is laminated between modules to create propagation firewalls. Module-to-module thermal propagation delays of 30+ minutes have been validated in third-party testing, sufficient to meet UL 9540A propagation-resistance requirements for grid-scale battery energy storage system (BESS) installation in occupied buildings and underground civil-defence applications.

Pack-to-Vehicle-Body Interface

The barrier layer between the battery pack upper cover and the vehicle passenger compartment floor uses MG-650-EV at 3.0 mm to delay heat transmission into the cabin during a runaway event. This installation supports GB 38031 occupant-egress timing requirements (5 minutes thermal escape time) and the equivalent provisions in ECE R100 and UN GTR 20. Pack-to-body installation typically combines aerogel felt with an outer steel firewall plate for combined thermal and mechanical impact protection.

Stationary BESS Modular Container Installations

Grid-scale battery energy storage systems deployed in 20' or 40' ISO container modules use MG-650-EV between battery rack columns and at the container wall interface to compartmentalise propagation risk. UL 9540A unit-level certification with MG-650-EV barriers reduces the required installation setback distance from occupied buildings, increasing the deployable BESS capacity per site for utility-scale renewable-integration projects.

Packaging & Storage

MG-650-EV is supplied as cut-to-size sheets matching customer cell-stack geometry, or as standard sheets (500 × 500 mm, 1000 × 500 mm) for module fabricators to die-cut in-house. Packaging is heat-sealed PE film with cleanroom-compatible outer cartons for direct entry into Class 8 (or better) battery assembly environments. Each batch ships with CoA, third-party UL 9540A test report, and a manufacturer compliance statement for GB 38031, ECE R100, and UL 9540A test programmes.

MOQ is 100 m² (typically 200–400 cell-stack barriers depending on cell geometry). For automotive Tier-1 supplier programmes, dedicated production lines with VDA 6.3 process audit and PPAP submission are available on request. Storage is dry, below 40°C, with clean-room intake protocols recommended to preserve the felt's particulate-shedding limit at battery-assembly hygiene standards.

Related Products

• MEGEL® Silica Aerogel — parent hub
• MEGEL MG-650-IP — industrial pipe variant
• MEGEL MG-650-MP — marine and LNG variant
• MEGEL MG-650-OR — oil refining variant
• MEGEL MG-650-UH — district heating variant