Hanwha Aero and SK Enmove Develop World's First 'Non-Flammable ESS'

Hanwha Aero and SK Enmove Develop Immersion Cooling Technology
ESS Internal Space Filled with Insulating Liquid for Cooling
Prevents Fire by Blocking Air and Dust Contact
"Collaborating with Hanwha Ocean to Build an Eco-friendly Ship Value Chain"

Hanwha Aerospace, in collaboration with SK Enmove, has developed the world's first 'non-flammable Energy Storage System (ESS).' The technology involves filling the ESS interior with an insulating fluid to lower the temperature and prevent fires.

On the 10th, Hanwha Aerospace and SK Enmove held a briefing on the 'Immersion Cooling ESS Technology,' announcing the development of a technology that fills lithium-ion battery modules with a cooling fluid (insulating liquid) to fundamentally block fires. The fluid is a substance with properties between liquid and gas, which prevents electrical conduction inside the module and cools down heat.

Immersion Cooling ESS Safety Test Video. A fire was artificially induced by thermal runaway of the battery, but the cooling fluid (insulating liquid) filling the lithium-ion battery module completely prevented the fire from spreading.
[Photo by Hanwha Aerospace]

Son Seung-hyun, head of the Energy Systems Center at Hanwha Aerospace, who spoke at the event, said, "An analysis of ESS fire incidents in Korea showed that over 95% of fire causes stem from insulation breakdown (short circuit accidents). We concluded that preventing insulation breakdown and extinguishing fires are the most critical aspects of fire prevention technology."

The immersion cooling technology also fundamentally blocks the ingress of dust and salt from outside, eliminating the possibility of fires caused by internal insulation breakdown. According to the company, the insulating fluid has about 3.5 times higher dielectric strength than air, enabling complete prevention of insulation breakdown. Even if a fire occurs, cooling and suffocation extinguishing through the insulating fluid surrounding the cells can be expected. This technology not only reduces the likelihood of fire but also allows immediate extinguishing if a fire does break out.

Introduction to Immersion Cooling ESS.
[Photo by Hanwha Aerospace]

Additionally, since this method cools the ESS directly, no separate piping or additional equipment is required. Center head Son explained, "Although this technology uses an 'immersion' cooling method, from the customer's perspective, no additional devices are needed, making it equivalent to 'natural cooling.'"

Hanwha Aerospace plans to apply the immersion cooling technology to pouch-type cells, which are difficult to fill with insulating fluid due to the lack of space between cells, unlike cylindrical cells. They are pursuing a patent application for a technology that applies a special structure to allow immersion cooling on the cell surface.

A company official stated, "We will also accelerate building a value chain in the eco-friendly ship sector by creating synergies with Hanwha Ocean in the marine business field."

Meanwhile, SK Enmove introduced the cooling fluid technology, a core material of the immersion cooling technology, on the same day. SK Enmove is the first domestic company to enter this field and has been developing technology since 2022 that can be used on land, aiming to apply it to fire-vulnerable data centers and electric vehicles.

Seo Sang-hyuk, head of SK Enmove's e-Fluids B2B Business Division, said, "Based on SK Enmove's world-class high-grade base oil technology, we will develop technology that maximizes fire prevention performance by utilizing differentiated additives."