context: The rate performance of the nanomesh cathode was tested at C-rates between 1.2 and 24C (corresponding to the volumetric currents of 269 mA cm−3 and 5387 mA cm−3, respectively). For each C-rate, five discharge–charge cycles were recorded, starting from the fully charged state. Therefore, we distinguish the “initial” discharge capacities (recorded after fully charging the cathode at 4.0 V for 1 hour) from the “continuous” discharge capacities recorded in the four consecutive cycles, which also depend on the charging kinetics at each C-rate. The discharge–charge profiles recorded in the first discharge–charge cycle at each C-rate are presented in Fig. 5c. The profiles have a similar shape at all the C-rates, showing that the higher currents did not affect the mechanism of Li storage in the cathode. The initial discharge capacity at 6C was 70% of the initial discharge capacity at 1.2C. When the cathode was discharged from the fully charged state at high rates of 18C and 24C (the current required for a theoretical full discharge in ∼3 min and 2.5 min, respectively), the initial capacity was still 50% and 45% of the initial capacity at 1.2C, demonstrating good rate performance of the cathode. The rate performance is, however, much inferior to that of LixMnO2-coated inverse Ni opals synthesisedby Zhang et al. (∼55% of 1.1C capacity at 743C). This is to be expected, as the mean pore size in the LixMnO2/nanomesh is about 40 nm which is significantly smaller than that in the LixMnO2/Ni opals (pore size of a few hundred nanometers). The small pore size lowers the diffusion rate of Li+ in the electrolyte within the electrode, which gradually becomes the rate-limiting factor during fast cycling of nanoporous electrodes. The differences in relative capacities of the nanomesh cathode are also amplified by the increased loss of active capacity after high rate cycling and prolonged charging at 4 V, as the initial discharge capacity at 1.2C in the 31st cycle was 73% of the initial discharge capacity at 1.2C in the first cycle (Fig. 5d).
answer: nanomesh 