| 초록 |
Potassium–ion batteries (KIBs) was recently evaluated as next-generation batteries due to similar standard redox potential of Li/Li+ and low cost of potassium resources. However, there are some challenges for searching suitable anode materials. i) Unstable cycle performance of carbonaceous materials due to severe volume expansion ii) metal oxide due to small host for accommodating large ionic size of potassium. In this work, we report ordered mesoporous niobium nitride/N-doped carbon hybrids (m-NbN/NC) as anodes for KIBs for the first time. The electrode delivers reversible capacities of 145 mA h g-1 at 100 mA g-1. Additionally, the capacity retention reached almost 100% after 2000 cycles showing superior cyclability. In situ XRD and ex situ SEM analyses were performed to verify the change of m-NbN/NC structure during cycling. Interestingly, mesopore structure was well maintained and accompanied by small strain, which is ascribed to high proportion of surface-controlled reaction. |
