Disclosed is a process for producing semiconductor nanowires having a diameter or thickness from 2 nm to 100 nm, the process comprising: (A) preparing a semiconductor material particulate having a size from 50 nm to 500 m, selected from Ga, In, Ge, Sn, Pb, P, As, Sb, Bi, Te, a combination thereof, a compound thereof, or a combination thereof with Si; (B) depositing a catalytic metal, in the form of nanoparticles having a size from 1 nm to 100 nm or a coating having a thickness from 1 nm to 100 nm, onto surfaces of the semiconductor material particulate to form a catalyst metal-coated semiconductor material; and (C) exposing the catalyst metal-coated semiconductor material to a high temperature environment, from 100 C. to 2,500 C., for a period of time sufficient to enable a catalytic metal-assisted growth of multiple semiconductor nanowires from the particulate.

Provided is graphene-encapsulated phosphorus anode particulate for a lithium or sodium ion battery, the particulate comprising: (A) a core comprising one or a plurality of phosphorus material-decorated graphene sheets, wherein the decorated graphene sheets have a length/width from 5 nm to 100 m and contain single-layer or few-layer graphene and the phosphorus material is in a form of particles or coating having a diameter or thickness from 0.5 nm to 10 m and is selected from red phosphorus, black phosphorus (including phosphorene), violet phosphorus, a metal phosphide, MP.sub.y, or a combination thereof, wherein M=Mn, V, Sn, Ni, Cu, Fe, Co, Zn, Ge, Se, Mo, Ga, In, or an alloy thereof, and y=1-4; and (B) an encapsulating shell that embraces or encapsulates the core, wherein the encapsulating shell comprises multiple graphene sheets and have a thickness from 0.34 nm to 5 m.

According to the present invention, there is provided a technique making it possible to improve suitably the performance of a nonaqueous electrolyte secondary cell in which a SEI film is formed on the surface of a negative electrode active material. The nonaqueous electrolyte secondary cell disclosed herein includes a positive electrode 10, a negative electrode 20, and a nonaqueous electrolytic solution, wherein a negative electrode SEI film 29 including at least a LiBOB skeleton and a fluorosulfonic acid skeleton is formed on the surface of a negative electrode active material 28, and a positive electrode SEI film 19 including at least a phosphoric acid skeleton is formed on the surface of a positive electrode active material 18. Where the component amount of the LiBOB skeleton in the negative electrode SEI film 29 is denoted by I.sub.B, the component amount of the fluorosulfonic acid skeleton in the negative electrode SEI film 29 is denoted by I.sub.S, and the component amount of the phosphoric acid skeleton in the positive electrode SEI film 19 is denoted by I.sub.P, a formula (1) represented by 4I.sub.B/I.sub.S10 and a formula (2) represented by 5 mol/m.sup.2I.sub.P15 mol/m.sup.2 are satisfied. Furthermore, the BET specific surface area of the negative electrode active material is 3.5 m.sup.2/g or more and 5.0 m.sup.2/g or less, and the component amount I.sub.B of the LiBOB skeleton is 4.3 mol/m.sup.2 or more.

A method for synthesizing an alkali metal-based phosphorous compound includes contacting an elemental alkali metal with elemental phosphorous to create a mixture and applying a pressure of less than 20 gigapascals to the mixture for forming the alkali metal-based phosphorous compound.

To provide a method for forming a storage battery electrode including an active material layer with high density in which the proportion of conductive additive is low and the proportion of the active material is high. To provide a storage battery having a higher capacity per unit volume of an electrode with the use of a storage battery electrode formed by the formation method. A method for forming a storage battery electrode includes the steps of forming a mixture including an active material, graphene oxide, and a binder; providing a mixture over a current collector; and immersing the mixture provided over the current collector in a polar solvent containing a reducer, so that the graphene oxide is reduced.

This disclosure relates to an SO.sub.2-based electrolyte for a rechargeable battery cell containing at least one conducting salt of the Formula (I)

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wherein M is a metal selected from the group consisting of alkali metals, alkaline earth metals, metals of group 12 of the periodic table of the elements and aluminum; x is an integer from 1 to 3; the substituents R, R.sup.2, R.sup.3 and R.sup.4 are each independently selected from the group consisting of C.sub.1-C.sub.10 alkyl, C.sub.2-C.sub.1 alkenyl, C.sub.2-C.sub.1 alkynyl, C.sub.3-C.sub.10 cycloalkyl, C.sub.6-C.sub.14 aryl, and C.sub.5-C.sub.14 heteroaryl; and Z is aluminum or boron.

A nonaqueous electrolyte secondary battery includes a positive electrode, a negative electrode, and a nonaqueous electrolyte having a lithium ion conductivity, and the negative electrode includes a negative electrode collector, a negative electrode active material layer provided on a surface of the negative electrode collector, and a coating film which at least partially covers a surface of the negative electrode active material layer and which has a lithium ion permeability. The coating film contains a lithium compound which contains an element M, an element A, an element F, and lithium; the element M is at least one selected from the group consisting of P, Si, B, V, Nb, W, Ti, Zr, Al, Ba, La, and Ta; and the element A is at least one selected from the group consisting of S, O, N, and Br.

A cathode material for a lithium-ion secondary battery of the present invention is active material particles including central particles represented by General Formula Li.sub.xA.sub.yD.sub.zPO.sub.4 (0.9<x<1.1, 0<y1, 0z<1, and 0.9<y+z<1.1; here, A represents at least one element selected from the group consisting of Co, Mn, Ni, Fe, Cu, and Cr, and D represents at least one element selected from the group consisting of Mg, Ca, Sr, Ba, Ti, Zn, B, Al, Ga, In, Si, Ge, Sc, and Y) and a carbonaceous film that coats surfaces of the central particles, in which a coarse particle ratio in a particle size distribution is 35% or more and 65% or less.

An electrochemical cell and method of use, including an anode of metal, an air permeable cathode, an electrolyte between the anode and the cathode, and a transition metal phosphide catalyst on the cathode or between the cathode and the electrolyte. Also, a method of generating electrical current with an electrochemical cell by introducing a transition metal phosphide catalyst on a cathode side of the electrochemical cell. The catalyst can be in the form of any suitable nanostructure, such as molybdenum phosphide nanoflakes.

An electrode active material includes a dopant (M.sup.2) and a lithium iron phosphate host material, where the electrode active material is represented as LiM.sup.2.sub.xFe.sub.1xPO.sub.4; M.sup.2 is a transition metal or main group metal; x is 0.01 to 0.15; the electrode active material exhibits an increased ionic conductivity compared to a lithium iron phosphate (LiFePO.sub.4) without the dopant; and the electrode active material has a particle size distribution characterized by a D.sub.50 greater than or equal to 1 m.