A process for etching a substrate comprising polycrystalline silicon to form silicon nanostructures includes depositing metal on top of the substrate and contacting the metallized substrate with an etchant aqueous solution comprising about 2 to about 49 weight percent HF and an oxidizing agent.

The present disclosure relates to the technical field of secondary battery, and discloses a positive electrode material and a preparation method and use therefor, a lithium-ion battery positive electrode poly piece, and a lithium-ion battery.

An electrode including an electrochemical layer defining a surface having a plurality of dimples formed thereon is provided. The dimples have an average lateral size greater than or equal to about 100 nm to less than or equal to about 100 μm, and an average depth greater than or equal to about 100 nm to less than or equal to about 50 μm. In certain variations, the dimples are formed in situ by applying a current to the electrochemical layer. In other variations, the dimples are formed by moving a roller having a plurality of shapes defined thereon along one or more surfaces of the electrochemical layer. In still other variations, the dimples are formed by contacting one or more surfaces of the electrochemical layer with a chemical etchant.

An anode for batteries having a columnar nanostructured porous germanium for its active material. This nanostructured porous germanium can be produced with the novel etching method disclosed herein. Such anode can be easily mass-produced with the presented method that requires pre-existing, affordable and easy to integrate equipment. In some embodiments, the produced columnar porous germanium can be directly used as a monolithic anode after its etching nanostructuration for on-chip anodes for example, where the anisotropic nanostructured germanium acts as the active material and where the remaining bulk germanium layer act as the current collector. This can be easily implemented in lithium batteries. The cycle life of such anodes could be extended by a factor of 26 and 1.8 for high rate and high energy applications, respectively.

Various implementations of a method of forming an electrochemical cell include providing a first electrode, a second electrode, a separator between the first and second electrodes, and an electrolyte in a cell container. The first electrode can include silicon-dominant electrochemically active material. The silicon-dominant electrochemically active material can include greater than 50% silicon by weight. The method can also include exposing at least a part of the electrochemical cell to CO.sub.2, and forming a solid electrolyte interphase (SEI) layer on the first electrode using the CO.sub.2.

A more efficient and lower cost method for producing electrochemically stable, and thus safe from thermal runaway, high electrochemical capacity coated lithium nickelate is disclosed. The coated nickelate hydroxide particles are formed from a mixed metal sulfate solution (MMS) serving as the starting material that is obtained from recycled lithium ion and/or nickel metal hydride batteries. The coating of the particles includes a relatively small amount of cobalt/manganese oxide forming the surface of the nickelate particles, while the core of the particles includes a relatively large amount of nickel in relation to the weight of the coating. Battery cathode electrodes may be manufactured by using the obtained coated lithium nickelate particles as the cathode active material (CAM) in forming the battery cathodes.

One variation of a battery unit includes: a substrate including silicon and defining a cell, wherein the cell includes a base encompassed by a continuous wall and a set of posts extending normal to the base; an electrolyte material coating vertical surfaces of each post, in the set of posts, and vertical surfaces of the continuous wall in the cell; a cathode material filling the cell over the electrolyte material, between posts in the set of posts, and between the set of posts and the continuous wall; a seal extending along a top of the continuous wall; and a cathode current collector bonded to the seal, electrically coupled to the cathode material, and cooperating with the substrate to enclose the cell to form a single-cell battery.

A process for etching a substrate comprising polycrystalline silicon to form silicon nanostructures includes depositing metal on top of the substrate and contacting the metallized substrate with an etchant aqueous solution comprising about 2 to about 49 weight percent HF and an oxidizing agent.

A composite anode for a zinc-based battery device is disclosed. The composite anode includes a pretreated Zn layer with one or more first coating layers, where in the Zn layer comprises a Zn film and a pretreated current collector substrate with one or more substrate coating layers. The pretreated Zn layer is pretreated by one or more of polishing, grinding, sanding, etching, and cleaning and the pretreated current collector substrate is pretreated by one or more of polishing, grinding, sanding, etching, and cleaning.

This invention relates to materials for the negative electrode in non-aqueous rechargeable alkali-ion batteries in free-standing form. In particular, this invention relates to the use of metal ribbon that is produced by melt spinning directly as a battery electrode. The invention also relates to a method producing a highly dispersed, multiphase composite material in a single step, as well as a way to generate porosity while maintaining the ‘binder-free’ and ‘additive-free’ characterization of the electrode.