Recherche

Degradation of the solid-electrolyte interface occurring during cycling is currently one of the most challenging issues for the development of all-solid-state batteries. Here we designed a unique electrochemical custom made cell for operando X-ray photoelectron spectroscopy (XPS) capable of maintaining high mechanical pressure with reliable electrochemistry and able to monitor in real-time the surface (electro-)chemical reactivity at the interfaces between the different composite.

Li-rich nanoparticles of Li_1+xMn_2-xO₄ doped with Al, Co or Ni are successfully synthesized using a facile, fast and efficient microwave-assisted hydrothermal route. In this study, we demonstrate that nanocrystallinity and cationic doping play an important role in improving the electrochemical performance with respect to LiMn₂O₄ microparticles.

All-solid-state lithium ion batteries represent a promising battery technology for boosting the volumetric energy density and promising a superior safety. In this study excellent cycling stability of graphite anode material have been demonstrated in combination with sulfide-based solid electrolyte. Furthermore we evaluated the stability of the graphite-electrolyte interface by analyzing the normalized cumulative irreversible charge during cycling experiments.

X-ray photoemission electron microscopy (XPEEM) with its excellent spatial resolution is a well-suited technique to elucidate the complex electrode-electrolyte interface reactions in Li-ion batteries. It provides element-specific contrast images and enables the acquisition of local X-ray absorption spectra on single particles. Here we demonstrate the strength of post mortem measurements and we show the first electrochemical cell dedicated for operando experiments in all-solid-state batteries.

We report an in-depth investigation of the local atomic geometry, electronic and crystallographic structure evolution of nano-sized LiMn₂O₄ using operando XAS and XRD to shed light on (de-)lithiation mechanism when cycled in wide voltage range of 2.0 to 4.3 V vs Li⁺/Li.

The growth of crystalline Li-based oxide thin films on silicon substrates is essential for the integration of next-generation solid-state lithionic and electronic devices. In this work, we employ a 2 nm γ-Al₂O₃ buffer layer on Si substrates in order to grow high quality crystalline thin films Li₄Ti₅O₁₂ (LTO).

We demonstrate the capability of conventional laboratory XPS to determine the anions solvation shell of Li⁺ cation within 1M of LiTFSI and 1M of LiFSI salts dissolved in (EMIM⁺-FSI^-) and (EMIM⁺-TFSI^-) ionic liquids. The binding energy difference between the N1s components originating from the EMIM⁺ cation and from TFSI^- or FSI^- anions, solvating the Li⁺, confirms that both TFSI^- and FSI^- contribute simultaneously to the Li⁺ solvation.

All-solid-state lithium batteries are a promising alternative for next generation of safe energy storage devices, provided that parasitic side reactions and the resulting hindrances in ionic transport at the electrolyte-electrode interface can be overcome. Motivated by the need for a fundamental understanding of such interface, we present here real-time measurements of the (electro-)chemical reactivity and local surface potential at the electrified interface Li₃PS₄ and LiCoO₂ using operando X-ray photoelectron spectroscopy.