Porous electroactive material
AssigneeNexeon Limited
InventorsPhilip John Rayner, Melanie J. Loveridge
Life of this patent
Estimating the term…
Abstract
A composition including a plurality of electroactive porous particle fragments including silicon as an electroactive material is characterized in that each porous particle fragment includes a network of pores defined and separated by silicon containing walls. The network of pores suitably has a three dimensional arrangement of pores extending through the volume of the particle in which the pore openings are provided on two or more planes over the surface of the particle. The composition is useful as an electroactive material that is able to form an alloy with lithium and can be used in the fabrication of anodes for use in lithium ion secondary batteries. A method of fabricating the silicon containing porous particle fragments is also disclosed.
Claims40
A composition comprising silicon-containing electroactive fractals derived from porous particles, each of said fractals having a volume and being selected from the group consisting of:
- a fractal having a substantially irregular shape or surface morphology, the fractal being derived from a silicon material originally defining or bounding pores or a network of pores within the porous particle;
- and
- a fractal having a substantially irregular shape or surface morphology, the fractal comprising a random or ordered network of linear, branched or layered elongate elements, the fractal being derived from a silicon material comprising a random or ordered network of linear, branched or layered elongate elements within the porous particle, wherein one or more discrete or interconnected voids or channels are defined between the elongate elements of the network,
- wherein each of said fractals itself does not comprise pores, voids, channels, or a network of pores, voids or channels extending through the volume of the fractal;
- wherein each of said fractals comprises at least one peak, trough, bump or ridge disposed over the surface thereof;
- has a spiky appearance;
- and/or has a ridged appearance;
- wherein the composition optionally further comprises silicon-containing pore-containing fragments derived from porous particles, the pore-containing fragments comprising a network of pores, cavities and channels, which pores, cavities and channels are separated and defined by silicon-containing walls within the pore-containing fragment, and wherein fragments and fractals having an average pore wall thickness or an average fractal thickness in the range 50 nm to 2 μm comprise at least 50% of the volume of the fragments and fractals.
A composition, comprising 5 to 40 wt % of the silicon-containing electroactive material according to claim 1 and 60 to 95 wt % of an electroactive carbon material.
A composition comprising silicon-containing electroactive fractals, each of said fractals being selected from the group consisting of:
- a fractal comprising a substantially irregular shape or surface morphology and an average thickness in the range 0.05 to 2 microns;
- and
- a fractal comprising a network of linear, branched or layered elongate elements having an average thickness in the range 0.05 to 2 microns
- wherein each of said fractals
- itself does not comprise pores, channels or a network of pores or channels extending through the volume of the fractal;
- and
- comprises at least one peak, trough, bump or ridge disposed over each surface thereof;
- has a spiky appearance;
- and/or has a ridged appearance;
- and
- wherein at least 10 vol% of the fractals have a maximum overall dimension in the range 1 to 40 μm.
Dependencies are inferred from the claim text.