Vanadia xerogel nanocathodes used in lithium microbatteries

Microbatteries with nanoscale features were made. Alumina filtration membranes having pores 200 nm in diameter served as the “jackets” to hold a PEO–lithium triflate electrolyte. Graphite particles approximately 75 μm in diameter were placed on the membrane covering numerous electrolyte-filled pores. The bottom of the pores were filled with V2O5 xerogel making cathode structures having a circular surface area with a diameter of 200 nm. In some cases, the V2O5 xerogel was filled with 35% carbon nanotubes making a nanocomposite cathode material that exhibited better performance. In effect, microbatteries of numerous parallel nanocells were made. These microbatteries were charged and discharged and, though they had low capacities ranging from 3 to 18 mAh/g, it was shown that these small lithium batteries could function in a viable manner.