Fig. 1: Synthesis and physicochemical characterization of MSCNFs.
From: Codoped porous carbon nanofibres as a potassium metal host for nonaqueous K-ion batteries

a Synthetic route of MSCNFs and the corresponding composite K anode. b PXRD patterns of MSCNFs. c Pore distribution of MSCNFs and the corresponding N2−77 K adsorption isotherms (inset). d–f SEM images of MSCNFs. The red dashed lines highlight the porous structure of the MSCNFs. g TEM image and h HRTEM image of MSCNFs. i EDS elemental mapping of MSCNFs in HAADF mode.