Li–S/Li-O2 batteries have great potential to meet energy storage requirements for Electrified Aircraft propulsion applications. However, due to the need for oxygen storage and supply systems, the complicit balance of plant significantly decreases both the gravimetric and volumetric energy density of Li-O2 battery systems. For the Li-S battery, however, the main obstacle – “rapid capacity fade on cycling” due to shuttling effects and volumetric change, has to be resolved. In phase I, collaborating with the University of Utah, Chemtronergy developed a unique all solid-state Li-S battery (ASSLSB) consisting a novel highly conductive thin polymer composite electrolyte and a highly-performing sulfur cathode, potentially capable of integrating with an industrial roll-to-roll battery manufacturing process readily for scaling-up. The composite solid polymer electrolyte (SPE) showed a conductivity as high as 2.2x10-4 S/cm and electrochemical window > 6.26 V at room temperature. Coin cells constructed with the novel SPE and unique sulfur cathode showed initial discharge specific capacity as high as 1500 mAh/g at room temperature, while capable of maintaining at 510 mAg/g after 100 cycles. In Phase II, a prototype Li-S battery pouch cell will be developed, followed by proof-of-concept demonstration. Successful development of the SPE and high-performance sulfur cathode will eliminate the use of flammable organic substances in the electrolyte while suppressing the polysulfide dissolution and lithium dendrite formation, thus making the Li-S batteries safer and durable.
Through improving cycle life and safety, the proposed all solid state Li-S battery will address the key limitation for space applications. With high safety and long cycle life, ASSLSB would meet multi-use or cross platform space energy storage applications, and result in significant mass and volume savings and operational flexibility, including Electrical Aircraft propulsion (EAP), EVA space suits and tools, human example, lunar and martian landers, science platforms and surface solar arrays.
The proposed ASSLSB can be widely used in consumer electronic, electric vehicles and charging stations, tourist coaches, yachts, wind and solar energy storage power, traffic signals, solar hybrid street lighting, UPS power supply, home energy storage, coal miner, disaster relief emergency, communication base stations, telecommunications, etc.