Advanced Space Energy Storage that Incorporates Long Cycle Life at High Depths of Discharge

ABSTRACT: The goal of this technology development is to design, develop and test Li-ion battery cells with long cyclic life composing an advanced cathode. There are number of candidate cathode and anode materials are considered promising candidates for lithium ion battery due to their large capacity and relatively good rate capability, low self-discharge and relatively good capacity retention as well as ease of monitoring state of charge. However, their cyclic life is still far from satisfying DOD"s needs for space application as stated above. Main challenges for current cathode materials include considerable deterioration of the cycle stability due to structural changes, dissolution of transition metal and oxygen; formation of passive layer from decomposition of electrolyte, impedance growth; and thermal instability of cathode material. In this proposed research, we will develop, evaluate and validate advanced materials (including anode, cathode and electrolyte) for use in Li-ion battery. In Phase I, we have demonstrated that novel cathode material can deliver high initial specific energy with high capacity retention. In Phase II, prototype Li-ion cells will be designed and fabricated with selected cathode and anode materials. BENEFIT: Rechargeable battery with high energy density (>200 Wh/kg) and long cycle life (>60,000) has application in military communications satellites. Light weight and long lasting battery is also essential for Army battle field application, unmanned aerial vehicles (UAVs), Navy"s All Electric Ship and also all the department of defense (ex. EM Railgun and Free Electron Lasers). The use of high-energy-density, high-depth-of-discharge batteries will improve power system efficiency and lifetime. In addition, long lasting fast charging battery is very attractive to implantable power sources, consumer electronic device (lap-top computer, cell phones, digital cameras, etc.) users and handheld tool users, especially when"mobile"is becoming essential indispensable in our life. Medical application is another possibility such as medical devicesX-ray machine, ultrasound system etc.