Objectives

Objective 1. HC materials synthesized and characterized. REACHED!!

Tailored Hard Carbon (HC) materials will be prepared by mild chemical synthesis routes starting from vegetal waste biomasses (e.g. nuts shells, leaves, etc.). The goal is to obtain a rational series of HC samples with (a) controlled C/N/O/H contents, (b) tailored mesoporosity and (c) specific degree of graphitization. Structure and morphologies will be studied by X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM).

Objective 2. HC electrodes performance in NIBs tested and sodiation reaction studied. REACHED!!

HC electrodes will be formulated and tested in Na half cells (NIB). The goal is to verify the performance of the HC rational series and evaluate the electrochemical properties of the SEI, in respect to bulk properties and electrolytes. Operando techniques, e.g. Small/Wide Angle X-Ray Scattering (SAXS/WAXS) and X-Ray Diffraction (XRD), will be used to investigate the bulk and morphological changes of HCs upon sodiation. The goal is to correlate the alteration of bulk properties of HCs upon cycling with the SEI features. 

Objective 3. Polarized XES operando test to visualize the SEI growth. REACHED!!

Operando SEI growth visualized by High Resolution X-Ray Spectrometry (HRXRS) and experimental protocol validated. The growth of the SEI layer on selected HC electrodes will be analysed for the first time with a unique and original synchrotron technique (polarized X-ray spectroscopy or HRXRS) able to quantify the species distribution resolved space (down to nanometer scale) and time (seconds) exploiting an original effective set-up (figure 2), allowing also texture analysis. The coupling of HRXRS with electrochemical cells in an operando configuration is the core objective of REALSEI. Operando results will be validated by standard ex situ techniques for surface and bulk HC/SEI analyses and correlated to O2 operando achievements.