A positive electrode for a secondary battery including a positive electrode current collector, and a positive electrode mixture layer containing a positive electrode active material and disposed on a surface of the positive electrode current collector. The positive electrode mixture layer contains a first positive electrode active material having a compressive strength of 400 MPa or more, and a second positive electrode active material having a compressive strength of 250 MPa or less. When the positive electrode mixture layer is divided into a first region and a second region having the same thickness, the first positive electrode active material is contained more in the first region than in the second region, and the second positive electrode active material is contained more in the second region than in the first region.

A secondary battery includes a positive electrode, a negative electrode, and an electrolytic solution. The positive electrode includes a positive electrode active material layer. The positive electrode active material layer includes a lithium-nickel composite oxide of a layered rock-salt type.

There is provided a method for collecting and reusing an active material from positive electrode scrap. The method of reusing a positive electrode active material of the present disclosure includes (a-1) immersing a positive electrode scrap comprising an active material layer on a current collector into a basic solution to separate the active material layer from the current collector, (a-2) thermally treating the active material layer in air for thermal decomposition of a binder and a conductive material in the active material layer, and collecting an active material in the active material layer, (b) washing the active material collected from the step (a-2) with a lithium compound solution which is basic in an aqueous solution and drying, and (c) annealing the active material washed from the step (b) with a lithium precursor to obtain a reusable active material.

The present disclosure relates to a positive electrode slurry for a lithium-sulfur battery including a positive electrode active material, an electrically conductive material, a binder and a solvent, where the ratio of the average particle diameter (D.sub.50) of the positive electrode active material and the positive electrode slurry is 1.5 or less, and the phase angle at 1 Hz of the positive electrode slurry is 50° or more. The positive electrode slurry for the lithium-sulfur battery of the present disclosure exhibits excellent flowability even while having a high solid content, thereby making it possible to manufacture a positive electrode for a lithium-sulfur battery with excellent electrochemical properties and improving the productivity and economic feasibility of the manufacturing process of the positive electrode for the lithium-sulfur battery.

A lithium transition metal oxide electrode including an additional metal is provided herein as well electrochemical cells including the lithium transition metal oxide electrode and methods of making the lithium transition metal oxide electrode. The lithium transition metal oxide electrode includes a first electroactive material including Li.sub.1+aNi.sub.bMn.sub.cM.sub.dO.sub.2, where 0.05≤a≤0.6; 0.01≤b≤0.5; 0.1≤c≤0.9; zero (0)≤d≤0.3; b+c+d=1 or a+b+c+d=1; and M represents an additional metal, such as W, Mo, V, Zr, Nb, Ta, Fe, Al, Mg, Si, or a combination thereof.

Provided is a lithium-containing oxide precursor solution for coating an electrode active material that is capable of improving the coverage of a coating layer that is formed by applying the lithium-containing oxide precursor solution to the surface of powder of the electrode active material and king it, and that is easy to handle in a normal atmosphere because a solution composed mainly of water is used as a solvent. The lithium-containing oxide precursor solution for coating an electrode active material includes Li in an amount of 0.1 mass % or more and 5.0 mass % or less, at least one element selected from Nb, F, Fe, P, Ta, V, Ge, B, Al, Ti, Si, W, Zr, Mo, S, Cl, Br, and I in an amount of 0.05 mass % or more and 35 mass % or less, and water in an amount of 60 mass % or more and 98.4 mass % or less. The value of absorbance of the solution at a wavelength of 660 nm is 0.1 or less, and the value of surface energy thereof is 72 mN/m or less.

The present disclosure belongs to the technical field of lithium battery cathode materials, and discloses a preparation method of multiple carbon-coated high-compaction lithium iron manganese phosphate, comprising the following steps: (1) synthesizing a carbon and vanadium co-doped ferromanganese phosphate precursor through a co-precipitation method, sintering, and removing crystal water to obtain an anhydrous ferromanganese phosphate precursor; (2) adding lithium phosphate, a supplemental phosphorus source, an organic carbon source, a dopant and deionized water, and performing ball milling, wet sanding, spray drying and sintering to obtain an intermediate material; and (3) adding deionized water and the organic carbon source, then performing ball milling, sanding, spray drying, sintering and air jet pulverization to obtain multiple carbon-coated high-compaction lithium iron manganese phosphate.

There is provided a positive electrode for an alkaline secondary battery and an alkaline secondary battery having good output properties and cycle life. To that end, a positive electrode (10) for alkaline secondary battery is obtained by laminating a flexible metal substrate (11) having flexibility; a primer layer (12) having conductivity provided on one or both surfaces of the substrate (11); and a positive electrode composite material layer (13) provided on the primer layer (12) and containing a positive electrode active material, a binder resin, and a first conductive material.

A positive-electrode material for a lithium ion secondary battery contains a lithium complex compound that is represented by the formula: Li.sub.1+aNi.sub.bMn.sub.cCo.sub.dTi.sub.eM.sub.fO.sub.2+α, and has an atomic ratio Ti.sup.3+/Ti.sup.4+ between Ti.sup.3+ and Ti.sup.4+, as determined through X-ray photoelectron spectroscopy, of greater than or equal to 1.5 and less than or equal to 20. In the formula, M is at least one element selected from the group consisting of Mg, Al, Zr, Mo, and Nb, and a, b, c, d, e, f, and a are numbers satisfying −0.1≤a≤0.2, 0.7<b≤0.9, 0≤c<0.3, 0≤d<0.3, 0<e≤0.25, 0≤f<0.3, b+c+d+e+f=1, and −0.2≤α≤0.2.

An electrode for batteries that does not include a metal-film-type current collector is disclosed herein. In some embodiments, the electrode comprises a composite having a core-shell structure including a core having an electrode active material, and a metal material coated on or doped in the surface of the core. A secondary battery having the electrode has increased capacity and energy density and exhibits improved lifespan characteristics.