Large aircraft continue to use fossil fuels as their primary energy source, and there remains little doubt that will remain true for years to come. However, NASA has been pushing aerospace electrification research forward through its green aviation initiatives.
Battery technology is fine for some light-duty applications, such as UAVs, drones or lighter-than-air vehicles, but it does not supply enough power density or range for passenger airplanes or helicopters. Additionally, lithium (Li)-ion batteries are the primary power source for electric vehicles (EVs) and large consumer electronics, yet they do not meet the stringent safety requirements of aerospace standards. This is the reason parcels containing Li-ion batteries often have stickers indicating “not for aviation cargo” or to use caution if the package is damaged.
Due to this, NASA has expanded research in different solid-state batteries, through its SABERS program, which do away with the liquid electrolyte chemicals. This would eliminate the potential for thermal runaway, the most prominent safety issue with Li-ion batteries.
Investigating solid-state batteries
NASA engineers needed to resolve a few key challenges of solid-state batteries. First up was determining which materials would be best to hold a charge with solid, dense electrolytes. The teams settled upon sulfur and selenium and envision a sulfur supply chain consisting of oil refining byproducts. They are also using a new material – a type of porous graphene that retains normal graphene’s mechanical properties, but further reduces the weight of the material. The porous graphene has higher surface area, chemical reactivity and can be precision manufactured, ultimately improving the material’s ionic conductivity and energy storage.
Also, the NASA team has discovered new ways to improve discharge voltages from solid-state batteries, which were typically too low to power devices. SABERS research initially increased the traditional voltage by a factor of 10, and then a factor of 5 with additional experimentation.
Although the research is primarily focused on developing a safe, powerful battery for aerospace applications, NASA is keenly aware that a solid-state battery would be a benefit to automotive applications. They plan to design a battery that is both scalable and easy to build an EV around.
The possible impact of NASA's solid-state battery is tremendous, and it promises to be an invaluable asset for aerospace and automotive applications alike. Implications of this achievement are far reaching, and it could no doubt revolutionize electrically powered transportation.
Tesla's Model Y 4680 batteries are rated at a sub-300 Wh/kg energy density. In comparison, NASA's SABERS battery technology has far surpassed these figures, with an incredible energy density of 500 Wh/kg. Moreover, solid-state batteries have been proven to reach an 80% charge within 12 minutes compared with their Li-ion counterparts, which generally take much longer. This new technology can also store up to 50% more energy than a typical Li-ion EV battery, while it requires less cooling during operation.
Not only does this reduce overall weight but it also increases safety by allowing operation at higher temperatures than traditional Li-ion batteries. This novel technology is set to revolutionize the electric vehicle and aircraft industries in the coming years and could lead to more efficient and safer vehicles than ever before.
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To achieve these the NASA SABERS team has had to rely on other NASA departments and teams, as well as various external partners, such as Georgia Tech, U.S. Argonne National Laboratory and U.S. Pacific Northwest National Laboratory. Between both the rapid development of solid-state battery technology and the wide proliferation of its understanding, it is likely that solid-state batteries become a significant disruptor in powering aviation.
Conclusion
NASA's solid-state batteries offer many advantages over traditional liquid electrolyte Li-ion batteries when it comes to energy density and weight reduction. With their incredible stability, fast charging times, and ability to be easily packed into a smaller size, the potential applications for solid-state batteries are boundless, from electric vehicles and spacecrafts to robotics and consumer electronics. As technology continues to advance, it is certain that solid-state batteries will continue to shape our future.
