A nanonet-enabled Li ion battery cathode material with high power rate, high capacity, and long cycle lifetime.

The performance of advanced energy conversion and storage devices, including solar cells and batteries, is intimately connected to the electrode designs at the nanoscale. Consider a rechargeable Li ion battery, a prevalent energy storage technology, as an example. Among other factors, the electrode material design at the nanoscale is key to realizing the goal of measuring fast ionic diffusion and high electronic conductivity, the inherent properties that determine power rates, and good stability upon repeated charge and discharge, which is critical to the sustainable high capacities. Here we show that such a goal can be achieved by forming heteronanostructures on a radically new platform we discovered, TiSi(2) nanonets. In addition to the benefits of high surface area, good electrical conductivity, and superb mechanical strength offered by the nanonet, the design also takes advantage of how TiSi(2) reacts with O(2) upon heating. The resulting TiSi(2)/V(2)O(5) nanostructures exhibit a specific capacity of 350 Ah/kg, a power rate up to 14.5 kW/kg, and 78.7% capacity retention after 9800 cycles of charge and discharge. These figures indicate that a cathode material significantly better than V(2)O(5) of other morphologies is produced.