EticaAG and Shell sign immersion-cooled BESS deal

EticaAG and Shell have signed a strategic collaboration deal that commits both parties to accelerating the development of immersion-cooled battery energy storage systems (BESS).

Under the agreement, the US-based BESS manufacturer will continue to use Shell’s Mivolt biodegradable ester-based liquid as a dielectric fluid to cool its battery modules. Shell is committed to providing technical support and joint engagement with safety authorities, standards organizations and industry stakeholders.

EticaAG offers immersion-cooled storage products for grid-scale and commercial and industrial (C&I) applications but, unlike conventional liquid-cooled BESS, the company’s energy storage units put battery cells in direct contact with a readily biodegradable dielectric fluid.

“The cells are actually submerged like in a bathtub in the module,” EticaAG President Matthew Ward told pv magazine in June 2025

Dielectric fluids, which are electrically nonconductive, are key to the immersion-cooled approach, to avoid any risk of shorting the battery cell. The benefit comes from the thermal conductivity of the fluid, which is lower than water on a watts per meter-kelvin basis, but significantly more thermally conductive than air.

EticaAG argues its immersion approach to BESS cooling delivers more consistent thermal regulation, and improves degradation control and safety when compared to typical air- or liquid-cooled systems.

In a press release, Gavin Wang, chairman of Etica Battery, a founding joint-venture partner of EticaAG, said that integrating Shell’s biodegradable ester liquid into the company’s immersion cooled system will help customers operate with greater confidence “especially in sectors where safety and uptime are non-negotiable.”

“This collaboration represents a major step forward in making advanced thermal management the new global standard for BESS,” Wang said.

Jason Wong, global executive vice president, Shell Lubricants, added that the collaboration will build on Shell’s work producing thermal management fluids for data centers and electric vehicles.

“We’re excited to together showcase how immersion cooling technology can enhance safety, reliability and readiness of BESS for the demanding applications of tomorrow – unlocking more value with less emissions towards a more resilient, sustainable future.”

The two companies signed the deal at the Abu Dhabi Formula 1 Grand Prix, held across Dec. 5 to 7, 2025.