A method of producing solid lithium hexafluorophosphate (LiPF.sub.6) includes reacting lithium fluoride (LiF) in solid form with gaseous phosphorous pentafluoride (PF.sub.5) in a liquid perhalogenated organic compound that is non-reactive with, i.e. is inert to, the PF.sub.5, thereby producing LiPF.sub.6 in solid form.

Reactions are disclosed in which phosphine and hydrogen fluoride are reacted to produce a phosphorus pentafluoride containing gas according the stoichiometry:
PH.sub.3+4F.sub.2.fwdarw.PF.sub.5+3HF Further reaction using the phosphorus pentafluoride to produce lithium hexafluorophosphate are also disclosed.

Battery electrolytes comprising: (a) a solvent suitable for use in a battery electrolyte such as an organic liquid solvent or an ionic liquid; (b) a lithium ion or sodium ion salt suitable for use in a battery electrolyte; and (c) a dispersion of nanoparticles of carbon, metal or metalloid oxides or hydroxides, carbides, nitrides, sulfides, graphene or MXene particles; or a combination thereof. The present invention is also directed to battery cells and batteries comprising these electrolytes and devices comprising these battery cells and batteries.

A computer-implemented method for determining a concentration of a component of an electrolyte in a lithium-ion or for a lithium-ion cell is provided. The method includes providing, to a spectrometer, instructions to capture a spectrum of a sample solution of the electrolyte and generate a signal. The method includes analyzing the signal to determine one or more spectral features of the spectrum. The method includes preparing a database of spectra corresponding to solutions having predetermined concentrations of the component of the electrolyte wherein the database includes a plurality for spectral features for each solution. The method further includes determining a machine learning (ML) model using the database of spectra. The method includes determining the concentration of the component of the electrolyte in the sample solution using the machine learning model.

Provided are an electrolyte for a lithium secondary battery and a lithium secondary battery including the electrolyte, wherein the electrolyte further includes a solid salt as an additive, wherein the solid salt contains one type of cation selected from ammonium-based cations and a thiocyanate anion (SCN.sup.). According an embodiment, the lithium secondary battery may have improved life characteristics by providing the electrolyte containing the additive.

A method of producing lithium difluorophosphate, the method including: a step of obtaining a first raw material mixture by mixing lithium hexafluorophosphate, at least one selected from the group consisting of an oxide of phosphorus (A) and a lithium salt of a phosphoric acid (B), and a hydrocarbon solvent having from 6 to 12 carbon atoms; a step of obtaining a second raw material mixture by removing at least a part of the hydrocarbon solvent contained in the obtained first raw material mixture; and a step of producing a crude product containing lithium difluorophosphate by reacting the second raw material mixture.

Disclosed are a hexafluorophosphate, phosphorus pentafluoride, a preparation method therefor and an application thereof. The preparation method for the hexafluorophosphate comprises the following steps: mixing a phosphoric acid solution of phosphorus pentoxide, sulfur trioxide and a fluoride in an inert gas atmosphere, sequentially performing evaporation concentration, dissolution, filtration and drying after the reaction, and obtaining the hexafluorophosphate. The method for preparing phosphorus pentafluoride from the hexafluorophosphate obtained by the preparation method provided by the present application comprises the following steps: mixing the hexafluorophosphate and a catalyst solution, carrying out catalytic reaction, and sequentially performing condensation, pressurized liquefaction and adsorption-based impurity removal, and obtaining phosphorus pentafluoride. The present application does not use phosphorus pentafluoride as a raw material to prepare the hexafluorophosphate, and does not use hydrogen fluoride as a raw material to produce phosphorus pentafluoride, thereby reducing risk related to production safety. Meanwhile, widely available chemical reagents of phosphorus pentoxide and sulfur trioxide are used as raw materials, thereby reducing the raw material cost and facilitating large-scale industrial production.

A process for producing a hexafluorophosphate salt comprises neutralizing hexafluorophosphoric acid with an organic Lewis base, to obtain an organic hexafluorophosphate salt. The organic hexafluorophosphate salt is reacted with an alkali hydroxide selected from an alkali metal hydroxide (other than LiOH) and an alkaline earth metal hydroxide, in a non-aqueous suspension medium, to obtain an alkali hexafluorophosphate salt as a precipitate. A liquid phase comprising the non-aqueous suspension medium, any unreacted organic Lewis base and any water that has formed during the reaction to form the precipitate, is removed. Thereby, the alkali hexafluorophosphate salt is recovered.

Reactions are disclosed in which phosphine and hydrogen fluoride are reacted to produce a phosphorus pentafluoride containing gas according the stoichiometry:

PH.sub.3+4F.sub.2.fwdarw.PF.sub.5+3HF

Further reaction using the phosphorus pentafluoride to produce lithium hexafluorophosphate are also disclosed.

A nickel based micro-structured material and methods are shown. In one example, the nickel based micro-structured material is used as an electrode in a battery, such as a lithium ion battery.