SABERS: Solid-State Lithium-Sulfur Battery Technology Portfolio

The first technique improves electrolyte densification, which is essential for ion conductivity and battery reliability overall. The process involves the use of a sintering aid (e.g., sulfur) to achieve denser and more stable electrolytes than are achievable through more common, high-temperature processes. Electrolytes that are denser and less porous have higher ion conductivity (thus better performance), longer cycle lives, and lower volatility. Aside from densification, this technique also significantly increased the base electrolyte's lithium wettability. The second innovation is a new cathode and electrolyte design using a mixed conducting material that can carry both ions and electrons, which simplifies the cathode’s composition by eliminating the need for separate ion and electron conductors. This catholyte is a composite that utilizes a mixed conducting material, replacing both the ion and electron conductors with a single material thus simplifying solid state cathode design from a 3-component to 2-component composite. The mixed material is composed of a metal chalcogenide, such as titanium disulfide (TiS2), which can act as a mixed conductor and contributes to energy storage. The addition of sulfur boosts energy capacity up to 33% compared to traditional cathode designs. Reducing single-conduction phases simplifies energy transport pathways and improves efficiency, making solid-state batteries easier to produce and safer to use. These two innovations work together to improve the state of the art, creating solid-state batteries with higher temperature tolerances and up to five times more energy capacity than current lithium-ion batteries. They stand together at a TRL 4 and are available for patent licensing individually or as part of the larger SABERS (LEW-TOPS-167) or SABERS 2.0 portfolio (LEW-TOPS-188).

Battery cells are sealed inside a strong, flexible pouch which is placed inside a lightweight pressure vessel filled with inert working fluid (e.g., argon gas, silicone oil) that applies a low pressure evenly around the pouch, ensuring uniform compression and eliminating directional stress on the cell. This case maintains constant pressure throughout the battery’s life cycle to ensure consistent contact between solid components, which optimizes performance and minimizes damage. The pressure necessary in this design is much lower than that in uniaxial systems, which allows for a less heavy packaging system. This lightweight design and improved technique may show particular relevance on large scales (e.g., aerospace, automotive), where onboard load weight and longevity are priorities. This isostatic battery case contributes to the SABERS 2.0 portfolio (LEW-TOPS-188), improving the state of the art for solid-state batteries. Currently at a TRL 4, the case is available to license independently or as part of the larger SABERS solid-state battery suite.

The original SABERS portfolio established foundational materials and architecture for solid-state lithium-sulfur batteries through innovations in graphene-based cathodes, solid electrolytes, and bipolar plate designs. Building on this foundation, SABERS 2.0 addresses critical challenges that have limited the practical implementation and scalability of solid-state batteries: cathode efficiency and electrolyte performance, anode interface stability, and cell-level packaging optimization. The SABERS 2.0 portfolio comprises four complementary innovations that work together to improve solid-state battery performance and manufacturing viability. Major licensable technologies in the SABERS 2.0 portfolio include: • Mixed Conducting Cathodes and Dense Electrolytes (LEW-TOPS-186): Two complementary innovations in electrolyte densification and catholyte formulation that simplify manufacturing and improve energy capacity, ion conductivity, and battery reliability. • Solvent-Free Anode Interlayer (LAR-TOPS-405): A dry-processed interlayer that prevents dendrite formation, maintains stable interfaces, and enables cost-effective, environmentally friendly manufacturing. • Isostatically Pressurized Cell Case (LEW-TOPS-187): A lightweight pressure vessel system that provides uniform compression to solid-state cells, eliminating the need for heavy machinery while enhancing performance and longevity. These technologies may be licensed independently, as part of the SABERS 2.0 suite, or in custom combination with the technologies in the original SABERS suite (LEW-TOPS-167).

In traditional batteries with liquid electrolytes, e.g., lithium-ion, each battery cell must be individually sealed, packaged, and electrically connected to other cells in the pack. The cells in solid-state batteries on the other hand may be stacked on top of one another with only a separation layer in between, called a bipolar plate. These bipolar plates or membranes if thin enough must be electrochemically inert to the electrode and electrolyte materials while providing electrical connectivity between the individual cells. Here, NASA has combined advances in the preparation of carbon nanomaterials and solid-state batteries to create extremely lightweight bipolar plates and membranes. These bipolar membranes will enable high energy density solid-state batteries unachievable with typical bipolar plate materials like stainless steel, aluminum, aluminum-copper, or conductive ceramics. The carbon bipolar membranes may be fabricated in multiple ways including but not limited to directly compressing carbon powders onto an electrode-electrolyte stack or separately making a film of the carbon material and dry pressing the film between other battery layers. The new bipolar membranes have been demonstrated in high energy density solid-state batteries in coin and pouch cells. The carbon bipolar membranes are at technology readiness level TRL-4 (Component and or breadboard validation in laboratory environment)and are available for patent licensing.

This invention is for scalable methods that allows preparation of bulk quantities of holey nanocarbons with holes ranging from a few to over 100 nm in diameter. The first method uses metal particles as a catalyst (silver, copper, e.g.) and offers a wider range of hole diameter. The second method is free of catalysts altogether and offers more rapid processing in a single step with minimal product work-up requirements and does not require solvents, catalysts, flammable gases, additional chemical agents, or electrolysis. The process requires only commercially available materials and standard laboratory equipment; and, it is scalable. Properties that can be controlled include: surface area, pore volume, mechanical properties, electrical conductivity, and thermal conductivity.