| 초록 |
Sodium metal anode is promising candidate for next-generation high-energy density batteries, because of its high theoretical capacity of 1166 mA h g-1 and low redox potential of -2.714 V. However, feasibility of sodium metal batteries is hindered by metal dendrite and large volume expansion in electrochemical cycling, which leads to unnecessary SEI formation, larger voltage hysteresis, and short circuit. Herein, we investigate effect of heteroatom and crystallinity of carbon-based materials in electrochemical performance such as activation overpotential, cycle ability and Coulombic efficiency (CE). We confirm that heteroatom-doped sites can function as activation sites and sodium-ion amicable spot and crystallinity of carbon microstructure has a decisive effect on cycling life by restraining decomposition of carbon. Consequently, sodium metal on carbon-based anode shows low activation overpotential (~4 mV), high CE about 99.9% and stable cycling performance over 1000 cycles. |
