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 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 lithium-ion battery may include a lithium-free cathode, a lithiated anode, and a separator/electrolyte between the lithium-free cathode and the lithiated anode. The lithium-free cathode may include FeOF and MnO.sub.2. The FeOF may be in the form of nanorods, and the MnO.sub.2 may be in the form of monolayer nanosheets. The FeOF nanorods may be sandwiched or wrapped by the monolayer MnO.sub.2 nanosheets.

A lithium-ion battery may include a lithium-free cathode, a lithiated anode, and a separator/electrolyte between the lithium-free cathode and the lithiated anode. The lithium-free cathode may include FeOF and MnO.sub.2. The FeOF may be in the form of nanorods, and the MnO.sub.2 may be in the form of monolayer nanosheets. The FeOF nanorods may be sandwiched or wrapped by the monolayer MnO.sub.2 nanosheets.

The present disclosure relates generally to an electrode produced with a non-toxic solvent, resulting in a homogeneous mixture with uniform distributions of a conductive additive and a binder. Electrodes produced according to the present disclosure feature narrow binder particle size distribution, which distinguishes such electrodes from typical electrodes produced via a N-Methyl-Pyrrolidone (NMP) process. The resulting microstructure promotes the flow of current through the electrode and has an improved cycling stability due, in part, to the binder's and the conductive additive's ability to bind with the active material particles used in the fabrication of the electrode.

The present disclosure relates generally to an electrode produced with a non-toxic solvent, resulting in a homogeneous mixture with uniform distributions of a conductive additive and a binder. Electrodes produced according to the present disclosure feature narrow binder particle size distribution, which distinguishes such electrodes from typical electrodes produced via a N-Methyl-Pyrrolidone (NMP) process. The resulting microstructure promotes the flow of current through the electrode and has an improved cycling stability due, in part, to the binder's and the conductive additive's ability to bind with the active material particles used in the fabrication of the electrode.

A method of making an electrode includes the step of mixing active material particles, radiation curable resin precursors, and electrically conductive particles to create an electrode precursor mixture. The electrode precursor mixture is electrostatically sprayed onto a current collector to provide an electrode preform. The electrode preform is heated and calendered to melt the resin precursor such that the resin precursor surrounds the active particles and electrically conductive particles. Radiation is applied to the electrode preform sufficient to cure the radiation curable resin precursors into resin.

A method of making an electrode includes the step of mixing active material particles, radiation curable resin precursors, and electrically conductive particles to create an electrode precursor mixture. The electrode precursor mixture is electrostatically sprayed onto a current collector to provide an electrode preform. The electrode preform is heated and calendered to melt the resin precursor such that the resin precursor surrounds the active particles and electrically conductive particles. Radiation is applied to the electrode preform sufficient to cure the radiation curable resin precursors into resin.

A composite cathode active material, a cathode including the same, a lithium battery, and a method of preparing a composite cathode active material are provided. The composite cathode active material includes: a core including a lithium transition metal oxide; and a shell disposed on and conforming to a surface of the core The shell includes: at least one first metal oxide represented by formula MaOb (0<a≤3 and 0<b<4, and if a 1, 2, or 3, b is not an integer); a carbonaceous material; and a doped fluorine (F) element, and the first metal oxide is disposed in a carbonaceous material matrix, and M is at least one metal selected from among Group 2 to Group 13, Group 15, and Group 16 metals in the Periodic Table.