Materials with New Design for Improved Lithium Ion Batteries

8. Nanocomposites as anode materials for lithium ion batteries: Synthesis, thermodynamic characterization and modeling of nanoparticular silicon dispersed in SiCN(O) and SiCO-based matrices

  • Contact:

     

    Professor Dr. Karsten Albe (JP8.1)
    Technische Universität Darmstadt

     

    Professor Dr. Ralf Riedel (JP8.2)
    Technische Universität Darmstadt
    Dr. Magdalena Graczyk-Zajac (JP8.2)
    Techniche Universität Darmstadt

     

    Professor Dr. Hans Jürgen Seifert (JP8.3)
    Karlsruhe Institute of Technology

     

     

We develop new anode materials consisting of nanosized silicon or tin dispersed in polymer-derived silicon carbonitride (SiCN) and silicon oxycarbide (SiOC) ceramics. During the first funding period optimized ceramic matrix material were prepared by exploring various synthesis routes, while the structural, thermodynamical and electrochemical properties of the composites were characterized. Based on the result that composites derived from amorphous Si and carbon-rich ceramics show the most promising properties, we now focus our research program on optimizing the electrochemical performance of nanoamorphous Si in carbon-rich ceramics. In parallel, nano-tin/ceramic composites are investigated. In detail, uniform distribution of the nanoparticles is achieved using new synthetic routes, e.g. single-precursor approach or impregnation of the ceramic. Mechanisms contributing to the analyzed increase of the capacity and the cycle stability are clarified by analyzing elemental composition, local solid-state structures, intercalation hosts and Li-ions mobility within the ceramic and the nanosized silicon/tin. Safety of the materials in comparison with commercial carbon-based anode materials is addressed using calorimetric measurements of the synthesized electrode materials. Experimental measurements are supported and guided by density-functional theory calculations, classical molecular-dynamics simulations and thermodynamic modeling.

Subproject 1 (Prof. Albe)

Subproject 2 (Prof. Riedel)

Subproject 3 (Prof. Seifert)