Development of "Tri-Guard Structure": A New Three-Layer Integrated Design for Battery Fire Countermeasures

Honjo state Co., Ltd. (Headquarters: Osaka City, Osaka Prefecture), in collaboration with ShinMaywa Industries, Ltd. (Headquarters: Takarazuka City, Hyogo Prefecture), has developed the "Tri-Guard Structure" as a new safety design for battery fire countermeasures.

Moving forward, the companies will promote the implementation of this technology in industrial sectors and pursue the joint development of application-specific products.

Background (Social Issues) In recent years, fires caused by lithium-ion batteries have occurred in various locations, including airports, commercial facilities, logistics sites, and transportation hubs.

Battery fires are characterized by their sudden onset and rapid spread. They are often accompanied by large amounts of smoke and toxic gases, which have been noted to pose risks of environmental impact and secondary damage.

On the other hand, measures for flame suppression, heat insulation, and smoke extraction are often implemented individually, and a structure that integrates the suppression of flames, heat, and smoke has not yet been sufficiently established.

Given this background, there is an increasing need for a new safety design that can suppress the expansion of damage in the event of a fire.

What is the "Tri-Guard Structure"? The "Tri-Guard Structure" developed by the two companies is a three-layer integrated safety structure designed to simultaneously suppress flames, heat, and smoke (toxic gases) generated during a fire, with the goal of extinguishing the fire and reducing the risk of environmental impact and secondary damage.

- Smoke Shield Layer: Suppresses the diffusion of smoke and toxic gases to the outside. - Heat Insulation Layer: Delays the transfer of high-temperature heat generated internally to the outside, suppressing heat diffusion. - Flame Shield Layer: Contains the fire source and suppresses the spread of fire to the surroundings.

This structure utilizes a combination of high-heat-resistant high-silica sheets*1 handled by Honjo state and insulation materials using recycled carbon fiber*2, which are being researched and developed by ShinMaywa Industries and Fuji Kashoku Co., Ltd.

*1 A high-silica fiber sheet with excellent flexibility and high heat resistance, boasting a maximum heat-resistant temperature of 1800°C. *2 Uses carbon fiber, which has a higher heat-resistant temperature than glass fiber insulation materials.

Future Outlook Based on the Tri-Guard structure, we aim to contribute to improved social safety and disaster mitigation as a countermeasure against the risk of battery fires, which is a growing concern alongside the progress of electrification.

Going forward, we will proceed with deployment in environments where ignition risks are anticipated, such as charging areas in logistics warehouses, battery storage spaces, and vehicle equipment. We will also consider its use as a safety measure in public spaces such as commercial facilities and lodging facilities.

Furthermore, the Tri-Guard structure is not limited to battery fire countermeasures and can be widely applied depending on the intended use.

By collaborating with facility operators who require fire countermeasures and manufacturers developing disaster prevention and safety products, we will advance the joint development of products and services utilizing the Tri-Guard structure to address the increasing fire risks that accompany social development.