Abstract: A positive electrode active material for a lithium secondary battery is disclosed. The positive electrode active material includes a secondary particle composed of an aggregate of a plurality of primary particles, in which the primary particle includes a nanocomposite structure in which rocksalt (Fm3m) structures and layered (R-3m) structures coexist as a physical mixture.

Abstract: A positive active material includes a secondary particle in which a plurality of primary particles is agglomerated. The positive active material is composed of, in which a compound containing nickel, lithium, and oxygen. An average angle between a reference line connecting a center portion of the secondary particle and a center portion of the primary particle provided at the outermost portion of the secondary particle and a particle orientation line penetrating the center portion of the primary particle provided at the outermost portion of the secondary particle and extending in parallel to an orientation direction of the primary particles is 12.2° or less. A concentration of the nickel in the compound is 59 mol % or more. The compound further includes an added metal composed of a different element from the nickel and the lithium. The added metal includes one or more of boron (B) and tungsten (W).

Abstract: The present invention relates to a positive electrode active material for a lithium secondary battery, the positive electrode active material comprising secondary particles consisting of a group of a plurality of primary particles, wherein the primary particles are provided on the surface of the secondary particles, the primary particles include oriented particles having a short axis and a long axis, the oriented particles include ultra-fine grains having a grain size of 0.1 µm to 0.5 µm, and the grain size is obtained by calculating an average cross-sectional area of the oriented particles as a square root.

Abstract: A cathode active material contains a secondary particle containing or consisting of a group of a plurality of primary particles. At least some of the primary particles disposed on the surface of the secondary particle include first primary particle in the form of flakes having a pair of first crystal faces facing toward each other. The first crystal faces are arranged in a radial direction, ends of the first crystal faces pair are provided with a plurality of crystal faces different from the first crystal faces to connect the ends of the first crystal faces pair. Longitudinal cross-sections of the first primary particle contain a pair of first crystal faces spaced apart from each other. Second and third crystal faces are disposed in the outermost surface of the secondary particle to be connected to each other at an angle.

Abstract: The present invention relates to a positive electrode active material comprising a secondary particle formed of agglomerates of a plurality of primary particles, wherein each primary particle comprises a first primary particle constituting a core portion of the secondary particle, and a second primary particle provided so as to surround the first primary particle and constituting a shell portion of the secondary particle. In particular, the first primary particle consists of a1 and a2, wherein the a1 is the average length of the major axis of the first primary particle, and the a2 is the average length of the minor axis perpendicular to the a1, wherein the a1 is equal to or greater than the a2. In addition, the second primary particle consists of b1 and b2, wherein the b1 is an average length of the major axis of the second primary particle, and b2 is an average length of the minor axis perpendicular to the b1, wherein the b1 is greater than b2, and the ratio (b1/b2) of the b1 to b2 is 1 to 25.

Abstract: An additive is for extending the useful life-span of the lead acid batteries. The additive is a safe and environmentally harmless material in the form of an aqueous liquid or an easy-to-use capsule. A method refurbishes lead acid batteries and extends their life-span.