A negative active material for a rechargeable lithium battery includes a core including a SiO.sub.2 matrix and a Si grain, and a coating layer continuously or discontinuously coated on the core. The coating layer includes SiC and C, and the peak area ratio of the SiC (111) plane to the Si (111) plane as measured by X-ray diffraction analysis (XRD) using a CuK ray ranges from about 0.01 to about 0.5.

The non-aqueous electrolyte liquid for a magnesium secondary battery according to one aspect of the present disclosure contains a non-aqueous solvent, a magnesium salt, and an aromatic heterocyclic compound which has an aliphatic hydrocarbon group which is a substituent. The aromatic heterocyclic compound includes at least one selected from the group consisting of a nitrogen atom, an oxygen atom, a phosphorus atom, and a sulfur atom as a constituent atom of the ring thereof. The aromatic heterocyclic compound is a non-electrolyte.

An activatable battery includes at least one cathode, at least one anode, at least one absorptive separator layer in contact with the anode and the cathode and a liquid electrolyte separated therefrom and provided in an apparatus which liberates the electrolyte in order to activate the battery in such a way that it comes into contact with the separator layer and penetrates through the latter at least to such an extent that the electrolyte electrically connects the anode and the cathode to one another. The anode is formed of lithium or a lithium-containing alloy and the cathode includes elemental carbon and is formed of an unsupported film including carbon nanotubes or of a film formed of carbon nanotubes. An electronic igniter, a process for producing an activatable battery and a method of using a film in a battery are also provided.

Disclosed are novel electrolytes, and techniques for making and devices using such electrolytes, which are based on compressed gas solvents. Unlike conventional electrolytes, disclosed electrolytes are based on compressed gas solvents mixed with various salts, referred to as compressed gas electrolytes. Various embodiments of a compressed gas solvent includes a material that is in a gas phase and has a vapor pressure above an atmospheric pressure at a room temperature. The disclosed compressed gas electrolytes can have wide electrochemical potential windows, high conductivity, low temperature capability and/or high pressure solvent properties. Examples of a class of compressed gases that can be used as solvent for electrolytes include hydrofluorocarbons, in particular fluoromethane, difluoromethane, tetrafluoroethane, pentafluoroethane. Also disclosed are battery and supercapacitor structures that use compressed gas solvent-based electrolytes, techniques for constructing such energy storage devices. Techniques for electroplating difficult-to-deposit materials using compressed gas electrolytes as an electroplating bath are also disclosed.

Disclosed are novel electrolytes, and techniques for making and devices using such electrolytes, which are based on compressed gas solvents. Unlike conventional electrolytes, disclosed electrolytes are based on compressed gas solvents mixed with various salts, referred to as compressed gas electrolytes. Various embodiments of a compressed gas solvent includes a material that is in a gas phase and has a vapor pressure above an atmospheric pressure at a room temperature. The disclosed compressed gas electrolytes can have wide electrochemical potential windows, high conductivity, low temperature capability and/or high pressure solvent properties.

An electrolyte composition and a metal-ion battery employing the same are provided. The electrolyte composition includes a metal halide, a solvent, and an additive. The solvent is an ionic liquid or organic solvent. The molar ratio of the metal halide to the solvent is from 1:1 to 2.2:1. The amount of additive is from 1 wt % to 25 wt %, based on the total weight of the metal halide and the solvent. The additive is monochloroethane, trichlorethylene, dichloroethane, trichloroethane, phosphorus trichloride, phosphorus pentachloride, methyl pyidine, methyl nicotinate, or a combination thereof.

An object is to provide a nonaqueous electrolyte and a nonaqueous-electrolyte secondary battery which have excellent discharge load characteristics and are excellent in high-temperature storability, cycle characteristics, high capacity, continuous-charge characteristics, storability, gas evolution inhibition during continuous charge, high-current-density charge/discharge characteristics, discharge load characteristics, etc. The object has been accomplished with a nonaqueous electrolyte which comprises: a monofluorophosphate and/or a difluorophosphate; and further a compound having a specific chemical structure or specific properties.

The present invention relates to a process for recovering a metal salt of an electrolyte dissolved in a matrix, said process consisting in subjecting the electrolyte to a liquid extraction with water.

Disclosed herein are electrochemical cells comprising electrodes prepared from layered materials comprising a substantially two-dimensional ordered array of cells having an empirical formula of M.sub.n+1X.sub.n, where M comprises a transition metal selected from the group consisting of a Group IIIB metal, a Group IVB metal, a Group VB metal, a Group VIB metal, and any combination thereof, X is C.sub.xN.sub.y wherein x+y=n, and n is equal to 1, 2, or 3. Also disclosed herein are batteries comprising the electrochemical cells and methods for electrochemically preparing MXene compositions with the use of the electrochemical cells.

A negative active material for a rechargeable lithium battery includes a core including a SiO.sub.2 matrix and a Si grain, and a coating layer continuously or discontinuously coated on the core. The coating layer includes SiC and C, and the peak area ratio of the SiC (111) plane to the Si (111) plane as measured by X-ray diffraction analysis (XRD) using a CuK ray ranges from about 0.01 to about 0.5.