Next-Generation Lithium-Sulfur Batteries with Enhanced Energy Density and Rate Capability

In the next generation combat vehicle power generation, energy storage, energy recharge, and energy distribution capabilities will be critically important. Full or partial electrification of a vehicle will enable significant improvements in offensive capabilities, agility & maneuverability, extended operational duration, on-board and exportable power, and reduced signatures for vehicles and mobility systems. To support the creation of a Highly Electrified Platform (HEP), there is a need for new energy storage technologies. Lithium-sulfur (Li-S) battery chemistry is promising to meet Army’s energy requirements because of its high theoretical specific energy of over 2,500 Wh/kg based on Li anode and S cathode with high specific capacity of over 3,800 and 1,600 mAh/g, respectively. Lynntech has already developed high energy and high safety Li-S batteries by using high loading sulfur cathode (>10 mg S/cm2). Lynntech has demonstrated Li-S pouch cells (36 cm2) with long cycle life (1,000 cycles), high rates (1 C), and excellent wide temperature performance (-18°C to +50°C). Building on Lynntech’s previous experience, Lynntech proposes to develop a next-generation Li-S battery with enhanced energy density and rate capability by using a stabilized Li metal anode, a multifunctional electrolyte, and a high capacity and high loading sulfur cathode. This next-generation Li-S technology can provide a specific energy of higher than 400 Wh/kg and a rate of >2C while maintaining the same safety and reliability standards as today’s Li-Ion batteries. During Phase I, Lynntech will develop improved electrodes and electrolytes, fabricate and demonstrate next-generation Li-S pouch cells with high energy density, good rate capability, long cycle life, and high safety. We will describe an initial design for prototype cells along with performance estimates and an improvement plan. Phase I deliverables include a design review including expected device performance, and a final report including Phase II plans. During Phase II, Lynntech will work with a battery manufacturer collaborator to develop a prototype of the battery to the specifications determined in Phase I design study. Lynntech will also conduct a formal risk assessment of the cell and thermal monitoring solutions for the transportation, storage and use of the battery in operational environments. Phase II deliverables include the delivery of a prototype for further Army evaluation, as well as quarterly and final reports detailing design and performance analysis of the prototype.