Rbd upgraded phi 5000c esca system

The crystal structures of the samples were identified by powder X-ray diffraction performed using a Philips X’pert pro X-ray diffractometer (Cu-Kα radiation, λ = 1.5418 Å) in the 2θ range from 10° to 70°. The morphologies of the different samples were observed with a scanning electron microscope (SEM, JEOL JSM-6700F) and a transmission electron microscope (TEM, JEOL-2010). The chemical element composition was examined quantitatively by an inductive coupled plasma atomic emission spectrometer (ICP-AES) with an emission spectrometer (Optima 2010 DV, Perkin-Elmer). The specific surface area of the pristine sample was measured by the adsorption–desorption of N₂ using an ASAP 2020 instrument. X-ray photoelectron spectroscopy (XPS) was carried out using a Perkin-Elmer RBD upgraded PHI-5000C ESCA system. Curve fitting of the XPS spectra was performed using a CasaXPS program and the binding scale was calibrated from the hydrocarbon contamination using the C 1s peak at 284.8 eV. Differential Scanning Calorimetry (DSC) analysis of the different samples in the delithiated state was carried out on an SDT Q600 from ambient temperature to 400 °C at a rate of 10 °C min⁻¹ under air flow.

The following are the details of the instrumentation: Agilent 7800 (Hitachi Ltd., Tokyo, Japan) was used for inductively coupled plasma mass spectrometry; JEM-2100F electron microscopy (JEOL, Tokyo, Japan) for high-resolution transmission electron microscopy (HRTEM); Veeco Nano-Scope Multimode IIIa (Veeco, Plainview, NY, USA) for atomic force microscopy (AFM); JEM Zetasizer Nano-ZS90 (Malvern Instruments, Malvern, UK) for hydrodynamic diameter measurement; Cary 50 spectrophotometer (Varian, Palo Alto, CA, USA) for ultraviolet (UV)–visible absorption spectra measurement; F-182 4500 spectrophotometer (Hitachi) for fluorescence measurement; and RBD-upgraded PHI-5000C ESCA system (Perkin Elmer, Waltham, MA, USA) for X-ray photoelectron spectroscopy (XPS).