Figure 2.
Electrochemical performance. (a) First charge–discharge curves of lithium–oxygen (Li–O2) cells with the six types of cathodes at a current density of 1.0 A g–1 and a specific capacity limit of 3,000 mAh g–1. (b) CV of the six types of cathodes in Li–O2 cells at a constant scan rate of 0.05 mV s–1. (c) The rate capability of the Li–O2 cells at the current density of 1.0 A g–1. Inset in c is the enlarged discharge profile of the Li–O2 cells with FNi and NPNi/FNi cathodes. (d) Comparison of the specific capacities of some noncarbonaceous cathodes previously reported. (e) FESEM images of the discharged Au/NPNi/FNi cathode when the discharge capacity is limited to 3,000 mAh g–1. (f) FESEM images of the discharged AuNi/NPNi/FNi cathode. Insets of e and f show the corresponding enlarged FESEM images. (g) A mechanism of electrochemical growth of the film-like and nanosheet-like Li2O2.
