Abstract:
This invention relates to a negative electrode material for lithium-ion batteries comprising silicon and having a chemically treated or coated surface influencing the zeta potential of the surface. The active material consists of particles or particles and wires comprising a core (11) comprising silicon, wherein the particles have a positive zeta potential in an interval between pH 3.5 and 9.5, and preferably between pH 4 and 9.5. The core is either chemically treated with an amino-functional metal oxide, or the core is at least partly covered with O y SiH x groups, with 1 y, or is covered by adsorbed inorganic nanoparticles or cationic mutivalent metal ions or oxides.
Abstract:
Provided herein are novel template electrode materials and structures for lithium ion cells. Related methods are also provided. According to various embodiments, an electrode can include a nanostructured template, an electrochemically active material layer coating the template, and a first intermediate layer between the nanostructured template and the electrochemically active material layer. In one arrangement, the nanostructured template includes silicide nanowires. The electrochemically active material may be any of silicon, tin, germanium, carbon, metal hydrides, silicides, phosphides, and nitrides. The first intermediate layer may facilitate adhesion between the nanostructured template and the electrochemically active material layer, electronic conductivity within the electrode, and/or stress relaxation between the nanostructured template and the electrochemically active material layer.
Abstract:
The present invention provides a method for treating silicon to form pillars ( see Figure 2), especially for use as the active anode material in Li-ion batteries. 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 etching solution comprises: 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 -, S2O8 2-, NO2 -, B4O7 2- and ClO4 - a mixture thereof. The treated silicon is suitably removed from the solution. Etched particles or fibres made by the process may be used in the form of a composite material in the active electrode material.
Abstract:
Embodiments of the present invention generally relate to methods and apparatus for forming an energy storage device. More particularly, embodiments described herein relate to methods of forming electric batteries and electrochemical capacitors. In one embodiment a method of forming a high surface area electrode for use in an energy storage device is provided. The method comprises forming an amorphous silicon layer on a current collector having a conductive surface, immersing the amorphous silicon layer in an electrolytic solution to form a series of interconnected pores in the amorphous silicon layer, and forming carbon nanotubes within the series of interconnected pores of the amorphous silicon layer.
Abstract:
The present invention in directed to the fabrication of thin aluminum anode batteries using a highly reproducible process that enables high volume manufacturing of the galvanic cells.
Abstract:
In a process of producing a porous layer of electrolytically depositable metal a support material (1) is immersed in an electrolytic medium (2) comprising ions of the metal and the metal is electrolytically deposited onto the support material (1) in the presence of an oxidising species which reacts with the metal to form a product which is reducible under the deposition conditions. In one form of process, a metal is deposited onto a support material (1) from an aqueous medium comprising ions of the metal, oxygen being introduced into the medium to pass in the vicinity of the support material. The process enables highly porous metal to be manufactured. The porous metal obtained is useful as catalytic material or as electrode material.
Abstract:
A rechargeable electrochemical device comprising an anode (6) composed chiefly of activated carbon, cathode (3) composed of a lithium alloy, and an electrolyte composed of an organic solvent in which a lithium salt is dissolved. Lithium content in the lithium alloy forming the cathode (3) is selected such that, if converted to the electric capacity under the charged condition, the capacity of this alloy ranges from 3 to 20 times the anode capacity that is obtained when the anode is discharged from 3.0 V to 2.0 V in a single-pole potential with respect to metal lithium. This constitution is able to provide a reliable rechargeable electrochemical device, which is proof against super-discharge and excellent in charge and discharge cycle life.
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.