Safe High Voltage Cathode Materials for Pulsed Power Applications

The mission of this proposed research is to develop a high-voltage, high-capacity, and inexpensive cathode material for lithium-ion batteries (LIB) capable of supporting high transient and pulsed loads while offering enhanced safety and lifecycle performance. Currently LIB is one of the most promising battery technologies that can provide higher energy density than other batteries. It also does not suffer from the memory effect and the loss of charge is relatively slow when not in use. Hence, high-performance LIB remains the preferred technology that would address a much broader range of energy source/storage for both military and civil applications if advanced cathode material with extreme operating capability could be realized. The innovation of this proposed research utilizes multiwall carbon nanotubes (CNT) as nano-architecture current collector array grown directly on a flexible Al (or graphite) foil. The CNT array is then coated with a high-performance active layer of ternary solid solution of orthosilicates Li2MnxFeyCozSiO4 (x + y + z = 1) as the cathode material. This novel approach of using nano-structured vertical-aligned CNT network provides a high surface area of attachment for Li2MnxFeyCozSiO4 nanoparticles and to minimize the contact resistance at the active material/current collector interface, thereby, maximizing the charge efficiency and the energy density of the cathode. Previous research performed at Vanderbilt University using vertical-aligned CNT impregnated with MnO2 nano-particles as electrodes [1] for electrochemical supercapacitor has recently resulted in record-breaking performance of ~1,000 F/cm3.