An object of the present disclosure relates to an electrode active material that has excellent discharge capacity and is used in an all solid fluoride ion battery. The present disclosure achieves the object by providing an electrode active material to be used in an all solid fluoride ion battery, the electrode active material comprising: an active material region that contains an active material component including a layered structure; and a coating region positioned in a surface side of the active material region; and a fluorine concentration in the coating region is higher than a fluorine concentration in the active material region.

A positive electrode active material which can improve cycle characteristics of a secondary battery is provided. Two kinds of regions are provided in a superficial portion of a positive electrode active material such as lithium cobaltate which has a layered rock-salt crystal structure. The inner region is a non-stoichiometric compound containing a transition metal such as titanium, and the outer region is a compound of representative elements such as magnesium oxide. The two kinds of regions each have a rock-salt crystal structure. The inner layered rock-salt crystal structure and the two kinds of regions in the superficial portion are topotaxy; thus, a change of the crystal structure of the positive electrode active material generated by charging and discharging can be effectively suppressed. In addition, since the outer coating layer in contact with an electrolyte solution is the compound of representative elements which is chemically stable, the secondary battery having excellent cycle characteristics can be obtained.

A positive electrode active material which can improve cycle characteristics of a secondary battery is provided. Two kinds of regions are provided in a superficial portion of a positive electrode active material such as lithium cobaltate which has a layered rock-salt crystal structure. The inner region is a non-stoichiometric compound containing a transition metal such as titanium, and the outer region is a compound of representative elements such as magnesium oxide. The two kinds of regions each have a rock-salt crystal structure. The inner layered rock-salt crystal structure and the two kinds of regions in the superficial portion are topotaxy; thus, a change of the crystal structure of the positive electrode active material generated by charging and discharging can be effectively suppressed. In addition, since the outer coating layer in contact with an electrolyte solution is the compound of representative elements which is chemically stable, the secondary battery having excellent cycle characteristics can be obtained.

A positive electrode active material for a secondary battery includes a lithium composite transition metal oxide including nickel (Ni), cobalt (Co), and manganese (Mn), and a glassy coating layer formed on surfaces of particles of the lithium composite transition metal oxide, wherein, in the lithium composite transition metal oxide, an amount of the nickel (Ni) in a total amount of transition metals is 60 mol % or more, and an amount of the manganese (Mn) is greater than an amount of the cobalt (Co), and the glassy coating layer includes a glassy compound represented by Formula 1.

Li.sub.aM.sup.1.sub.bO.sub.c  [Formula 1] wherein, M.sup.1 is at least one selected from the group consisting of boron (B), aluminum (Al), silicon (Si), titanium (Ti), and phosphorus (P), and 1≤a≤4, 1≤b≤8, and 1≤c≤20.

In one embodiment, the present disclosure relates to a positive electrode active material in which a lithium cobalt oxide is doped with a doping element including a metallic element and a halide element, wherein the positive electrode active material is represented by Formula 1 and satisfies Equation 1, and a positive electrode for a lithium secondary battery and a lithium secondary battery, either of which include the positive electrode active material:
Li(Co.sub.1-x-y-zM.sup.1.sub.xM.sup.2.sub.yM.sup.3.sub.z)O.sub.2-aH.sub.a  [Formula 1]
(2x+3y+4z−a)/(x+y+z+a)<2.5.  [Equation 1]

In one embodiment, the present disclosure relates to a positive electrode active material in which a lithium cobalt oxide is doped with a doping element including a metallic element and a halide element, wherein the positive electrode active material is represented by Formula 1 and satisfies Equation 1, and a positive electrode for a lithium secondary battery and a lithium secondary battery, either of which include the positive electrode active material:
Li(Co.sub.1-x-y-zM.sup.1.sub.xM.sup.2.sub.yM.sup.3.sub.z)O.sub.2-aH.sub.a  [Formula 1]
(2x+3y+4z−a)/(x+y+z+a)<2.5.  [Equation 1]

This application relates to the field of battery technologies, and in particular, to a high-compacted-density positive electrode material and an electrochemical energy storage apparatus. The positive electrode material includes a lithium-nickel transition metal oxide A and a lithium-nickel transition metal oxide B. The lithium-nickel transition metal oxide A is secondary particles, whose chemical formula is shown in formula I: Li.sub.a1(Ni.sub.b1Co.sub.c1Mn.sub.d1).sub.x1M.sub.1-x1O.sub.2-e1X.sub.e1. The lithium-nickel transition metal oxide B is a monocrystalline structure or a monocrystalline-like structure, whose chemical formula is shown in formula II: Li.sub.a2(Ni.sub.b2Co.sub.c2Mn.sub.d2).sub.x2M′.sub.1-x2O.sub.2-e2X′.sub.e2 (II). The positive electrode material of this application includes the large-particle lithium-nickel transition metal oxide A and the small-particle lithium-nickel transition metal oxide B to improve an energy density of the battery. A degree of crystallinity and particle size distribution of the mixed positive electrode material can improve a compacted density of the high-nickel active material, and ensure lower gassing and good cycle performance.

The present invention relates to a Li-rich antiperovskite-coated LCO-based lithium complex, a method of preparing the same, and a positive electrode active material and a lithium secondary battery, both of which include the LCO-based lithium complex. When a lithium complex in which a coating layer of a compound having a lithium-rich antiperovskite (LiRAP) crystal structure is formed on surfaces of LCO-based particles is applied as the positive electrode active material, the lithium complex is favorable for batteries which are operated at a high voltage, has high lithium ion conductivity, and can be applied to lithium secondary batteries which are driven at a high temperature due to high thermal stability.

The present invention relates to a Li-rich antiperovskite-coated LCO-based lithium complex, a method of preparing the same, and a positive electrode active material and a lithium secondary battery, both of which include the LCO-based lithium complex. When a lithium complex in which a coating layer of a compound having a lithium-rich antiperovskite (LiRAP) crystal structure is formed on surfaces of LCO-based particles is applied as the positive electrode active material, the lithium complex is favorable for batteries which are operated at a high voltage, has high lithium ion conductivity, and can be applied to lithium secondary batteries which are driven at a high temperature due to high thermal stability.

Provided is a positive electrode active material particle including a core that includes lithium cobalt oxide represented by the following Chemical Formula 1; and a shell that is located on the surface of the core and includes lithium cobalt phosphate represented by the following Chemical Formula 2, wherein the shell has a tetrahedral phase:
Li.sub.aCo.sub.(1-x)M.sub.xO.sub.2-yA.sub.y(1) wherein M is at least one of Ti, Mg, Zn, Si, Al, Zr, V, Mn, Nb, or Ni, A is oxygen-substitutional halogen, and 0.95a1.05, 0x0.2, 0y0.2, and 0x+y0.2,
Li.sub.bCoPO.sub.4(2) wherein 0b1.