| 초록 |
Hard carbons are considered a promising alternative to commercial graphite anode for sodium-ion batteries (NIBs). Na+ storage in hard carbons originates from intercalation (＞0.1 V vs. Na/Na+) and adsorption (＜0.1 V vs. Na/Na+), the latter of which deteriorates overall stability. Herein, we developed a double-layered hard carbon material, MCA-GL-600, that allows Na+ storage predominantly via intercalation. MCA-GL was prepared by self-templating approach which utilizes 2D organic crystal of triazine molecules as molecular template and carbon/nitrogen sources. Uniform coating of glucose on MCA followed by carbonization at 600 degrees C leads to formation of a double layered 2D carbon materials consisted of carbon nitride and amorphous carbon. The resulting MCA-GL-600 features turbostratic character and interlayer distance of 0.4 nm which are appropriate for Na+ intercalation in NIBs. The MCA-GL-600 delivers a high specific capacity of ~380mAh/g at 250mA/g after 100cycles, though the capacity of hard carbon anodes rarely reaches values beyond 300mAh/g in NIBs. |
