Isostatically Pressurized and Lightweight Cell Case for Solid-State Batteries

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).

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).

The SABERS innovators developed novel lithium-sulfur designs, including sulfur-selenium on graphene cathodes, and lightweight bipolar plate stacking and packaging designs. SABERS is unique in several aspects, in particular, it deploys graphene-based manufacturing processes for the cathode and bipolar plates, and it uses a solid-state electrolyte in place of the liquid electrolyte found in other lithium-sulfur battery designs. The team has achieved energy densities over 500 W-hr/kg, with ongoing development targeting further improvements. Coin cell and pouch prototype demonstrations have been successful and are ongoing. Major component technologies in SABERS include the following: • S/Se Cathode – Sulfur/Selenium on graphene scaffold (LEW-20228-1) • Solid Electrolyte – Solid-state electrolyte composites (LEW-20445-1) • Bipolar Stack – Graphene plates (LAR-20257-1) Robust computational models have been developed to support the battery materials design and are available to licensees to evaluate and optimize different materials combinations and performance targets. Further developments in catholyte formulations, anode interlayering, and packaging optimization are presented in SABERS 2.0 (LEW-TOPS-188). Individual technologies can be licensed from either suite, or entire portfolios can be licensed to support solid-state battery development programs.

The interlayer consists of lithiophilic metallic or metal-containing nanoparticles supported on holey graphene, a special carbon material perforated by small holes that enables dry processing. The composite interlayer guides uniform lithium deposition and maintain stability during cycling. The result is a thin, film-like material that can be integrated (via dry processes) into battery cells as standalone interlayers or combined with solid electrolyte and cathode powders to form bi- and tri-layer structures, separating anodes and electrolytes while encouraging efficient ionic movement and long cell lifecycles. Tests found that battery cells incorporating this dry-processed interlayer achieved ultrahigh current density and low overpotential, indicating that the interlayer prevents rough patches, resists dendrite formation, and supports efficient charge and discharge over time. The interlayer has demonstrated a high lithium-ion flux (i.e., a high critical current density of ~25 mA/cm²) and has shown that full battery cells incorporating the protective layer can be successfully cycled (with an areal capacity of 7 mAh/cm²). This innovation contributes to both the SABERS (LEW-TOPS-167) and SABERS 2.0 (LEW-TOPS-188) portfolios, improving the state of the art for solid state batteries. The anode interlayer is currently at a TRL 4 and is available to license independently or as part of the larger SABERS solid-state battery suite.

The generalized ultrasonic inspection method harnesses piezoelectric transducers and ultrasonic resonance spectroscopy to detect sub-500-micron defects in batteries. By analyzing the resonance behavior of high-frequency sound waves and employing novel data processing techniques, subtle structural changes in batteries can be identified. Two hardware setups were developed: one employing direct transducer contact and another utilizing ultrasonic measurements through a captured water column. Both configurations incorporate a scanning technique that captures spatial degradation data – rather than a single point measurement – enabling structural insights even in layers too thin for time-domain c-scan resolution. Processing of the data includes converting the measurements and reference time domain signals to the frequency domain, then normalizing the measurement signal in the frequency domain to determine the frequency dependent reflection coefficient. As a result, resonance behavior between the test specimen and apparatus can be isolated. This resonance-based approach is ideal for delicate materials unsuitable for high-powered laser excitation or full immersion testing, and the associated data-analysis allows the battery defects to be detected more efficiently. This NASA invention offers significant potential for highly sensitive, nondestructive enhancements of battery safety and quality control in industries such as automotive, aerospace, additive manufacturing, and composites.