Wacker Chemie Ag

Dennis Troegel

Stefan Haufe

Jelena Pantelic-Seidl

Eckhard Hanelt

Peter Gigler

The invention relates to composite core-shell particles wherein the core is a porous, carbon-based matrix which contains silicon particles enclosed in pores of the matrix; the pores containing the silicon particles have a diameter of &#x2265;60 nm as determined by scanning electron microscopy (SEM); the shell can be obtained by carbonizing one or more carbon precursors selected from among the group comprising tars, pitches, hard carbon, soft carbon and hydrocarbons having 1 to 20 carbon atoms, resulting in a non-porous shell.

Composite core-shell particles

The invention relates to methods for producing Si/C composite particles, characterised in that mixtures containing silicon particles, one or more oxygen-free polymers, one or more carbon additives based on a carbon modification and one or more liquid dispersing agents are dried by spray drying and the pre-composite particles thus obtained are thermally treated.

Production of Si/C composite particles

Composite Si/C particles containing silicon particles located within pores of a carbonaceous matrix are prepared by coating silicon particles with a sacrificial coating layer followed by coating with an organic carbon precursor to form precomposite particles. Thermal treating of the precomposite particles carbonizes the organic carbon precursor and releases the sacrificial material. The composite particles are useful in lithium ion battery anodes.

Method for producing Si/C composite particles

The invention provides processes for producing precomposite particles by mixing silicon particles, polyacrylonitrile and one or more carbon additives (C additives) based on one carbon polymorph, optionally one or more organic pore formers and optionally one or more inorganic additives, each in the form of a powder, wherein no solvent is added before and during the mixing, and the inorganic additives are selected from the group comprising halides of the alkali metals and alkaline earth metals, carbonates of the alkali metals, zinc oxide, magnesium carbonate and nickel sulfide, wherein the polyacrylonitrile, the silicon, particles and/or the C additives are wholly or partly initially charged prior to the mixing or are wholly or partly metered in during the mixing, with the proviso that, without polyacrylonitrile in the initial charge, the silicon particles and/or the C additives are at least partly metered in together with polyacrylonitrile or after addition of polyacrylonitrile. The invention further provides processes for producing Si/C composite particles, characterized in that the aforementioned precomposite particles are subjected to thermal treatment.

The invention relates to silicon/graphite/carbon composites (Si/G/C-composites), containing graphite (G) and non-aggregated, nanoscale silicon particles (Si), wherein the silicon particles are embedded in a carbon matrix (C). The invention also relates to a method for producing said type of composite, electrode material for lithium ion batteries containing said type of composite and to a lithium ion battery.

Si/G/C-composites for lithium-ion-batteries

The aluminum content of neopentasilane is reduced by treatment with organic compounds D which contain N, O, and/or S atoms and which have free electron pairs on these atoms.

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Ottensoos, Germany

Dennis Troegel