In a one-step method for preparing a lithiated silicon electrode, a suspension of a lithium precursor and a silicon precursor in a carrier liquid is plasma sprayed without a carrier gas. The carrier liquid is water, alcohol, ethylene glycol, or mixtures thereof. The lithium precursor is selected from the group consisting of a lithium phosphate, a lithium nitrate, a lithium sulfate, a lithium carbonate, and combinations thereof. The suspension excludes an active carbon material and a binder.

In a one-step method for preparing a lithiated silicon electrode, a suspension of a lithium precursor and a silicon precursor in a carrier liquid is plasma sprayed without a carrier gas. The carrier liquid is water, alcohol, ethylene glycol, or mixtures thereof. The lithium precursor is selected from the group consisting of a lithium phosphate, a lithium nitrate, a lithium sulfate, a lithium carbonate, and combinations thereof. The suspension excludes an active carbon material and a binder.

The present invention provides a positive-electrode active material for a lithium-ion secondary cell or a sodium-ion secondary cell, which can effectively exhibit more excellent charge/discharge characteristics; and a method for manufacturing the positive-electrode active material. Namely, the present invention relates to a positive-electrode active material for a secondary cell comprising an oxide represented by formula (A): LiFe.sub.aMn.sub.bM.sub.cPO.sub.4, formula (B): LiFe.sub.aMn.sub.bM.sub.cSiO.sub.4, or formula (C): NaFe.sub.gMn.sub.hQ.sub.iPO.sub.4; and carbon derived from a cellulose nanofiber supported thereon.

A method of producing a pre-sulfurized active cathode layer for a rechargeable alkali metal-sulfur cell; the method comprising: (a) Preparing an integral layer of porous graphene structure having a specific surface area greater than 100 m.sup.2/g; (b) Preparing an electrolyte comprising a solvent and a sulfur source; (c) Preparing an anode; and (d) Bringing the integral layer and the anode in ionic contact with the electrolyte and imposing an electric current between the anode and the integral layer (serving as a cathode) to electrochemically deposit nano-scaled sulfur particles or coating on the graphene surfaces. The sulfur particles or coating have a thickness or diameter smaller than 20 nm (preferably <10 nm, more preferably <5 nm or even <3 nm) and occupy a weight fraction of at least 70% (preferably >90% or even >95%).

A method of producing a pre-sulfurized active cathode layer for a rechargeable alkali metal-sulfur cell; the method comprising: (a) Preparing an integral layer of porous graphene structure having a specific surface area greater than 100 m.sup.2/g; (b) Preparing an electrolyte comprising a solvent and a sulfur source; (c) Preparing an anode; and (d) Bringing the integral layer and the anode in ionic contact with the electrolyte and imposing an electric current between the anode and the integral layer (serving as a cathode) to electrochemically deposit nano-scaled sulfur particles or coating on the graphene surfaces. The sulfur particles or coating have a thickness or diameter smaller than 20 nm (preferably <10 nm, more preferably <5 nm or even <3 nm) and occupy a weight fraction of at least 70% (preferably >90% or even >95%).

An immobilized selenium body, made from carbon and selenium and optionally sulfur, makes selenium more stable, requiring a higher temperature or an increase in kinetic energy for selenium to escape from the immobilized selenium body and enter a gas system, as compared to selenium alone. Immobilized selenium localized in a carbon skeleton can be utilized in a rechargeable battery. Immobilization of the selenium can impart compression stress on both the carbon skeleton and the selenium. Such compression stress enhances the electrical conductivity in the carbon skeleton and among the selenium particles and creates an interface for electrons to be delivered and or harvested in use of the battery. A rechargeable battery made from immobilized selenium can be charged or discharged at a faster rate over conventional batteries and can demonstrate excellent cycling stability.

According to a novel fabrication method, a new composition of matter includes a large percentage (e.g., 75% or higher percentage) of primary nanoparticles in the new composition of matter. The novel fabrication method reduces the size of nanoparticle clusters in material of the new composition of matter, allows fabrication of specific nanoparticle cluster sizes, and allows fabrication of primary nanoparticles. This new composition of matter can include a high permittivity and high resistivity dielectric compound. This new composition of matter, according to certain examples, has high permittivity, high resistivity, and low leakage current. In certain examples, the new composition of matter constitutes a dielectric energy storage device that is a battery with very high energy density, high operating voltage per cell, and an extended battery life cycle.

Provided herein are energy storage device cathodes with high capacity electrochemically active material including compounds that include iron, fluorine, sulfur, and optionally oxygen. Batteries with active materials including a compound of the formula FeF.sub.aS.sub.bO.sub.c exhibit high capacity, high specific energy, high average discharge voltage, and low hysteresis, even when discharged at high rates. Iron, fluorine, and sulfur-containing compounds may be ionically and electronically conductive.

Provided herein are energy storage device cathodes with high capacity electrochemically active material including compounds that include iron, fluorine, sulfur, and optionally oxygen. Batteries with active materials including a compound of the formula FeF.sub.aS.sub.bO.sub.c exhibit high capacity, high specific energy, high average discharge voltage, and low hysteresis, even when discharged at high rates. Iron, fluorine, and sulfur-containing compounds may be ionically and electronically conductive.

A solid state lithium carbon monofluoride battery includes an anode comprising Li, a solid electrolyte, and a cathode including CF.sub.x and LPS. The cathode can also include a carbon compound. The solid electrolyte can include LPS. The LPS can include β-Li.sub.3PS.sub.4. The cathode LPS can include β-Li.sub.3PS.sub.4. A method of making a battery is also disclosed.