Disclosed are a reaction tower, a production system, and a production method for producing potassium manganate. The reaction tower includes a reaction tower body and a bubble generator. The reaction tower body has a reaction chamber. The bubble generator includes an outer housing. The outer housing is disposed in the reaction chamber and has a gas flow channel therein. The outer housing is configured to direct an external reactant gas into the gas flow channel. The outer housing is provided with multiple first pores each having a diameter less than 10 mm, via which the gas flow channel communicates with the reaction chamber. The reaction tower is used in the production system. The reactant gas is introduced into the reaction chamber in the form of small bubbles by the action of the bubble generator, to increase the area of contact of the reactant gas with manganese ore powder and lye.

A positive electrode active material according to the present disclosure includes: a lithium composite oxide which includes Mn and at least one selected from the group consisting of F, Cl, and N, and S. The lithium composite oxide has a crystalline structure which belongs to the space group Fd-3m, and a relationship 1.40≤intensity ratio I.sub.Mn1/I.sub.Mn2≤1.90 is satisfied. The intensity ratio I.sub.Mn1/I.sub.Mn2 is a ratio of an intensity I.sub.Mn1 to an intensity I.sub.Mn2. The intensity I.sub.Mn1 and the intensity I.sub.Mn2 are intensities of a first proximity peak and a second proximity peak, respectively, of the Mn in a radial distribution function of the Mn included in the lithium composite oxide.

A mixed conductor represented by Formula 1:
A.sub.4+xM.sub.5-yM′.sub.yO.sub.12-δ,  Formula 1
wherein, in Formula 1, A is a monovalent cation, M is at least one of a divalent cation, a trivalent cation, or a tetravalent cation, M′ is at least one of a monovalent cation, a divalent cation, a trivalent cation, a tetravalent cation, a pentavalent cation, or a hexavalent cation, M and M′ are different from each other, and 0.3≤x<3, 0.01<y<2, and 0≤δ≤1 are satisfied.

A stabilized lithium ion cathode material comprising a calcined manganese oxide powder wherein the manganese on a surface is MnPO.sub.4, comprises an manganese phosphate bond, or the phosphate is bonded to the surface of the cathode material.

The present disclosure relates to a device comprising todorokite constructed of octahedra of manganese oxide forming a channel, wherein the channel contains a plurality of alkali ions but does not contain crystalline water molecules. In some aspects of the present disclosure, one of the alkali ions is magnesium and the channel may have a diameter of approximately one nanometer.

Provided are a method for producing a purified lithium compound excellent in production efficiency of the purified lithium compound, capable of being applied to various types of lithium compounds, and capable of reducing energy consumption in obtaining the purified lithium compound and a method for producing a lithium transition metal composite oxide using the purified lithium compound obtained by said production method. A method for producing a purified lithium compound includes a crushing step of disaggregating aggregation of a crude lithium compound containing a magnetic substance and a magnetic separation treatment step of conducting magnetic separation in a dry manner on the crushed crude lithium compound using a magnetic separator to remove the magnetic substance from the crushed crude lithium compound.

Provided are a method for producing a purified lithium compound excellent in production efficiency of the purified lithium compound, capable of being applied to various types of lithium compounds, and capable of reducing energy consumption in obtaining the purified lithium compound and a method for producing a lithium transition metal composite oxide using the purified lithium compound obtained by said production method. A method for producing a purified lithium compound includes a crushing step of disaggregating aggregation of a crude lithium compound containing a magnetic substance and a magnetic separation treatment step of conducting magnetic separation in a dry manner on the crushed crude lithium compound using a magnetic separator to remove the magnetic substance from the crushed crude lithium compound.

Methods for regenerating degraded cathode particles in lithium-ion batteries are provided through a combination of hydrothermal treatment of cycled electrode particles followed by short thermal annealing. The methods provide for directly regenerating high-performance LiCoO2 (LCO) and LiNixCoyMnzO2 (NCM) cathodes. Combining hydrothermal treatment with short thermal annealing to regenerate degraded LCO particles provides successful reconstruction of stoichiometric composition and desired crystalline structure from severely degraded cathode materials, and in further embodiments, successful regeneration of degraded NCM cathodes is demonstrated, which regenerates degraded NCM particles with electrochemical performance reaching that of new cathode materials.

A material synthesis method may comprise: adding at least one liquid precursor solution to an atomizer device; generating by the atomizer device an aerosol comprising liquid droplets; transporting the aerosol to a reactive zone for evaporating one or more solvents from the aerosol; and collecting particles synthesized from at least evaporating the aerosol.

A thermoelectric material, having a formula Tb.sub.xM1.sub.y-xM2.sub.zO.sub.w where M1 is one of Ca, Mg, Sr, Ba and Ra, M2 is at least one of Co, Fe, Ni, and Mn, x ranges from 0.01 to 5; y is 1, 2, 3, or 5; z is 1, 2, 3, or 4; and w is 1, 2, 3, 4, 5, 7, 8, 9, or 14. The thermoelectric material is chemically stable within 5% for one year and is also non-toxic. The thermoelectric material can also be incorporated into a thermoelectric system which can be used to generate electricity from waste heat sources or to cool an adjacent region.