Abstract: A powder comprising pillared particles for use as an active component of a metal ion battery, the pillared particles comprising a particle core and a plurality of pillars extending from the particle core, wherein the pillared particles are formed from a starting material powder wherein at least 10% of the total volume of the starting material powder is made up of starting material particles having a particle size of no more than 10 microns.

Abstract: A powder comprising pillared particles for use as an active component of a metal ion battery, the pillared particles comprising a particle core and a plurality of pillars extending from the particle core, wherein the pillared particles are formed from a starting material powder wherein at least 10% of the total volume of the starting material powder is made up of starting material particles having a particle size of no more than 10 microns.

Abstract: A powder comprising pillared particles for use as an active component of a metal ion battery, the pillared particles comprising a particle core and a plurality of pillars extending from the particle core, wherein the pillared particles are formed from a starting material powder wherein at least 10% of the total volume of the starting material powder is made up of starting material particles having a particle size of no more than 10 microns.

Abstract: A method of etching silicon of a material comprising silicon, the method comprising the steps of partially covering a silicon surface of the material comprising silicon with an elemental metal and then carrying out a metal-assisted chemical etching of the silicon by exposing the partially covered silicon surface to an etching composition, wherein at least some of the elemental metal for the metal-assisted chemical etching is formed by either: (a) exposing the silicon surface to a composition comprising metal ions, wherein the elemental metal forms by reduction of the metal ions and wherein the composition comprising metal ions is substantially free of HF, or (b) depositing the elemental metal directly onto the silicon surface.

Abstract: A method of etching silicon, the method comprising the steps of: electrolessly depositing a first metal onto a silicon surface to be etched, wherein the electrolessly deposited first metal partially covers the surface of the silicon to be etched; depositing a second metal that is different from the first metal over the silicon surface and the electrolessly deposited first metal, wherein a film of the deposited second metal covers the silicon surface to be etched; removing the first metal and the second metal from regions of the film of the deposited second metal that overlie the first metal to leave the second metal partially covering the silicon surface to be etched; and etching the silicon by exposing the silicon surface to an aqueous etching composition comprising an oxidant and a source of fluoride ions.

Abstract: A method for treating silicon to form pillars, especially for use as the active anode material in Li-ion batteries, is disclosed. The process is simple to operate on a commercial scale since it uses a solution containing only a small number of ingredients whose concentration needs to be controlled and it can be cheaper to operate than previous processes. The solution includes: 0.01 to 5M HF 0.002 to 0.2M of metal ions capable of nucleating on and forming a porous layer comprising regions of elemental metal on the silicon surface; 0.001 to 0.7M of an oxidant selected from the group O2, O3, H2O2, the acid, ammonium or alkali metal salt of NO3?, S2O82?, NO2?, B4O72? and ClO4? or a mixture thereof. The treated silicon is suitably removed from the solution.

Abstract: A powder comprising pillared particles for use as an active component of a metal ion battery, the pillared particles comprising a particle core and a plurality of pillars extending from the particle core, wherein the pillared particles are formed from a starting material powder wherein at least 10% of the total volume of the starting material powder is made up of starting material particles having a particle size of no more than 10 microns.

Abstract: A method for treating silicon to form pillars, especially for use as the active anode material in Li-ion batteries, is disclosed. The process is simple to operate on a commercial scale since it uses a solution containing only a small number of ingredients whose concentration needs to be controlled and it can be cheaper to operate than previous processes. The solution includes: 0.01 to 5M HF 0.002 to 0.2M of metal ions capable of nucleating on and forming a porous layer comprising regions of elemental metal on the silicon surface; 0.001 to 0.7M of an oxidant selected from the group O2, O3, H2O2, the acid, ammonium or alkali metal salt of NO3?, S2O82?, NO2?, B4O72? and ClO4? or a mixture thereof. The treated silicon is suitably removed from the solution.