Directional Oxygen Functionalization by Defect in Different Metamorphic?Grade Coal?Derived Carbon Materials for Sodium Storage

As the limiting factor for an energy storage technique from lab-scale to industrial-scale, cost means not only price of raw materials but also simplicity processing technics. In this work, oxygen functionalized carbon were obtained three representative different metamorphic-grade coals, that is, lignite, bitumite, anthracite. Oxygen functional groups like quinones, carboxylic anhydrides, and lactones are easier form near defects according thermogravimetric-mass spectrometry measurements density theory calculation. Considering highest amount C=O contained groups, low lignite derived exhibits a reversible capacity 259.7 mA h g?1 after 50 cycles at 0.03 A g?1, best among these micron sized coal-based carbons. The surface active sites contribute highly stable majority sodium evidenced by in situ Raman spectra cyclic voltammetry curves scan rates. work offer options industrial applications sodium-ion battery anode materials.