product collaboration

Paper-based separator technology solutions for the next generation of saltwater battery energy storage systems

As interest grows in alternative battery chemistries*, aqueous sodium‑based battery systems present unique material requirements for cell designers. Paper‑based separators offer strong compatibility with aqueous sodium electrolytes, supporting efficient electrolyte uptake and stable ion transport. This article examines these advantages and the role of collaboration in advancing safe, scalable energy‑storage solutions.

Superior wettability for better electrolyte uptake in aqueous sodium based battery systems

In aqueous sodium‑based battery systems, the separator must insulate the electrodes to prevent short circuits while remaining sufficiently porous to enable efficient ion flow. Because these systems rely on water‑based electrolytes, rapid and uniform wetting of the separator is essential for achieving consistent electrolyte distribution during the filling process. Paper‑based separators, such as delfort’s IonPort^®, excel in this area due to their naturally high wettability and hydrophilic fiber structure, which allows them to absorb aqueous electrolytes significantly faster than conventional film separators.

The engineered thickness and porous structure of battery separator paper also function as an efficient electrolyte reservoir, ensuring that water‑rich electrolytes penetrate evenly through the material. “Unlike films that often require surface treatments or coatings to achieve acceptable wetting, IonPort^® achieves rapid electrolyte uptake inherently, enabling cell manufacturers to reduce filling times by up to 26% and achieve greater process efficiency”, Alexander Onz, Technical Program Manager for IonPort^® at delfort. Its resistance to aqueous environments — supported by tunable pore structures and thickness profiles — further contributes to long‑term mechanical stability and precise ion transport.

Paper‑based separators also deliver advantages in thermal stability and non‑flammability, as paper does not shrink or melt under elevated temperatures. This enhances safety both during manufacturing and in end‑use applications. In addition, IonPort^® supports the sustainability goals of next‑generation saltwater and sodium‑ion technologies because it is made from renewable, recyclable materials, offering an environmentally responsible alternative to polymer‑based separator films.

How collaboration advances safe, sustainable energy storage batteries

Integrating IonPort^® into the saltwater battery design of Salty Enerji — a pioneer in safe, sustainable saltwater‑based energy storage — supports the development of safer and more environmentally responsible energy‑storage systems built around a non‑flammable, non‑toxic aqueous sodium electrolyte. This chemistry not only offers a safer alternative to lithium‑ion batteries but also reduces reliance on scarce raw materials. Paired with IonPort^® paper‑based separators, it gains natural compatibility with water‑rich electrolytes, stable ion transport, and a stronger overall environmental profile.

Within this collaborative framework, both teams refine interfaces, material interactions, and cell‑assembly processes to support reliable performance at scale. These developments flow into the Salty Enerji energy storage system, where large‑format cells are assembled into modular blocks for stationary energy‑storage applications. The use of IonPort^® in these systems reflects its suitability for aqueous sodium environments, including consistent electrolyte uptake, long‑term structural stability, and the thermal robustness required for this type of battery architecture.

Safety and sustainability are not optional features for the future of energy storage — they are requirements. By integrating delfort’s IonPort^® separator into our saltwater battery platform, we are strengthening a technology stack that is inherently safe, scalable, and aligned with circular economy principles

Pelin Keleş, Co-Founder at Salty Enerji

This collaborative advancement demonstrates how responsible material choices and coordinated development pathways can support the clean‑energy transition while meeting the practical needs of commercial energy‑storage deployments.

With superior wettability, fast electrolyte uptake, and strong compatibility with aqueous sodium‑ion chemistries, IonPort^® paper‑based separators offer battery manufacturers a reliable path toward high‑quality saltwater energy‑storage systems. Combined with close collaboration between technology partners, these materials help enable safer, scalable, and future‑ready battery solutions that meet the evolving needs of modern energy‑storage applications.