Electrode materials comprising an electrochemically active material, wherein said electrochemically active material comprises a layered potassium metal oxide. The layered potassium metal oxide may be of formula K.sub.xMO.sub.2. The invention also relates to electrodes, electrochemical cells and batteries comprising said electrode material. For example, said battery may be a lithium or lithium-ion battery, a sodium or sodium-ion battery, or a potassium or potassium-ion battery.

Supplemental lithium can be used to stabilize lithium ion batteries with lithium rich metal oxides as the positive electrode active material. Dramatic improvements in the specific capacity at long cycling have been obtained. The supplemental lithium can be provided with the negative electrode, or alternatively as a sacrificial material that is subsequently driven into the negative electrode active material. The supplemental lithium can be provided to the negative electrode active material prior to assembly of the battery using electrochemical deposition. The positive electrode active materials can comprise a layered-layered structure comprising manganese as well as nickel and/or cobalt.

A binder-free, self-supporting electrode including an electrochemically active material in the absence of a binder and a current collector is claimed. The electrochemically active material is a self-supporting transition metal oxide. A method of regenerating the electrode to restore capacity of the electrode is also claimed.

A positive electrode active material contains a lithium composite oxide and a covering material. The lithium composite oxide has a crystal structure that belongs to space group Fd-3m. The ration I.sub.(111)/I.sub.(400) of a first integrated intensity I.sub.(111) of a first peak corresponding to a (111) plane to a second integrated intensity I.sub.(400) of a second peak corresponding to a (400) plane in an XRD pattern of the lithium composite oxide satisfies 0.05≤I.sub.(111)/I.sub.(400)≤0.90. The covering material has an electron conductivity of 10.sup.6 S/m or less.

A positive electrode active material and a preparation process thereof, a sodium ion battery (5) and an apparatus containing the sodium ion battery (5) are described, the positive electrode active material satisfying the chemical formula of Na.sub.0.67Mn.sub.xA.sub.yB.sub.zO.sub.2±δ, in which A is selected from one or more of Co, Ni and Cr, B is selected from one or more of Mg, Al, Ca, Ti, Cu, Zn and Ba, 0.6<x<1, 0<y<0.1, 0.6<x+y<0.8, z>0, x+y+z=1, 0≤δ≤0.1, and (I) $\frac{3.33+2\left(\delta -y-z\right)}{4}<x<\frac{3.33+2\left(\delta -y-z\right)}{3}.$

A method for making a catalyst for ozone decomposition includes: adding a reducing agent into a water solution of a permanganate salt to obtain a first reaction liquid, and heating the first reaction liquid under continuous stirring to form a birnessite-type manganese dioxide; and adding the birnessite-type manganese dioxide into a water solution of an ammonium salt to obtain a second reaction liquid, and heating the second reaction liquid under continuous stirring to form the catalyst.

The invention provides primary batteries that incorporate a desodiated sodium transition metal oxide into the positive electrode (a cathode). Batteries of the invention using a desodiated sodium transition metal oxide in the cathode exhibit discharge voltages, battery capacities, and energy densities higher than a traditional Zn—MnO.sub.2 dry cell battery, such as a commercially available AA battery. These batteries are also advantageous over comparable lithium ion batteries due to the high abundance and low cost of sodium precursor materials with similar electrical performance.

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.

A LiMnO.sub.2 production method includes generating cubic crystal LiMnO.sub.2 nanoparticles by adding an organic solvent, manganese oxide nanoparticles, and lithium amide in a reaction vessel and heating in an inert atmosphere. and a washing and recovering the generated particles. Wurtzite type MnO nanoparticles are preferably used as the manganese oxide. As a result, LiMnO.sub.2 nanoparticles that have a substantially similar particle size to wurtzite type MnO nanoparticles can be obtained from an Mn raw material. Nanoparticles having a hollow structure can be obtained by controlling the reaction temperature.

The present invention relates to a positive electrode active material and a lithium secondary battery including the same, and more particularly, to a positive electrode active material which includes an overlithiated lithium manganese-based oxide including at least lithium, nickel, manganese and a doping metal, and in which the degradation in stability caused by excessive amounts of lithium and manganese in the lithium manganese-based oxide is mitigated and/or prevented by controlling the concentration of a transition metal in the lithium manganese-based oxide for each region, and a lithium secondary battery including the same.