There is provided a method of synthesizing a porous carbon-sulfur composite comprising the step of carbonizing a carbon material having a metal-organic framework (MOF) at a temperature of 800-1000° C. to produce a porous carbon, mixing and heating the porous carbon with sulfur to infuse the sulfur (melt diffusion) into the pores of the porous carbon and removing excess sulfur not infused into the pores or present on the surface of the porous carbon. There is also provided a cathode comprising the porous carbon-sulfur composite and a method of preparing the cathode by mixing with conductive carbon and a polymer binder. The cathode finds use in an electrochemical cell comprising a sodium or lithium anode.

Disclosed are a cathode materials suitable for an aluminium ion battery, wherein the cathode materials comprise a main group element nitride, and an oxide of a main group element or an oxide of a element in Group 1 to 13. The nitride is preferably a 2-dimensional layered material. Preferably, the ratio of the main group element nitride to the oxide is between 5:95 and 95:5 (by weight).

The present invention pertains to a positive electrode active material for a lithium secondary battery, the positive electrode active material having a layered structure and containing lithium, transition metals, fluorine (F), and oxygen, wherein the layered structure includes a lithium layer consisting solely of lithium and a transition metal layer consisting solely of transition metals including nickel, the nickel includes Ni.sup.3+ and Ni.sup.2+ in terms of oxidation number, and the ratio (Ni.sup.2+/Ni.sup.3+) of Ni.sup.2+ to Ni.sup.3+ increases as the fluorine content increases.

The disclosure relates to metal phosphorothioates, batteries comprising metal phosphorothioate, cells comprising metal phosphorothioate, and methods of making thereof.

A non-aqueous electrolyte secondary battery includes a positive electrode, a negative electrode, and an electrolyte solution, wherein the positive electrode includes a composite oxide including lithium as a first metal, and a second metal X other than lithium; in the composite oxide, the second metal X includes Ni, Al, and Mn; the second metal X does not contain Co or the atomic ratio Co/X of Co to the second metal X is 0.02 or less; and the electrolyte solution contains a chain carboxylic acid ester having 2 to 4 carbon atoms, and a cyclic compound having a ring structure composed of 2 oxygen atoms and 3 to 5 carbon atoms.

Provided is a lithium secondary battery comprising: a positive electrode including a positive electrode active material; a negative electrode including a negative electrode active material; and a first functional layer between the positive electrode and the negative electrode, wherein the first functional layer includes plate-like polyolefin particles having an average diameter of 1 μm to 8 μm, and the positive electrode includes a positive electrode active material layer including a positive electrode active material and a flame retardant, or has a stacked structure including a positive electrode active material layer and a second functional layer including a flame retardant.

A positive electrode active material having a crystal structure that is unlikely to be broken by repeated charging and discharging is provided. A positive electrode active material with high charge and discharge capacity is provided. One embodiment of the present invention is a positive electrode active material containing lithium, cobalt, nickel, and oxygen; in which a molar ratio of lithium, cobalt, and nickel is lithium: cobalt: nickel=1:1−x: x (0.3<x<0.75); in which the average of a bond distance between cobalt and oxygen and a bond distance between nickel and oxygen is longer than or equal to 1.94×10.sup.−10 m and shorter than or equal to 2.1×10.sup.−10 m in a crystal structure of the positive electrode active material; and in which the average of an angle formed between a line connecting cobalt to an adjacent oxygen and a line connecting cobalt to another adjacent oxygen and an angle formed between a line connecting nickel to an adjacent oxygen and a line connecting nickel to another adjacent oxygen is greater than or equal to 86.5° and less than 90°.

Disclosed herein is a stabilised Na-ion oxide P3 phase of formula (I): P3-Na.sub.xM.sub.yO.sub.z Where, x>0.66, 0.8≤y≤1.0, z≤2; and M is selected from one or more of the group consisting of a 3d transition metal, a 4d transition metal, Al, Mg, B, Si, Sn, Sr and Ca. The stabilised Na-ion oxide P3 phase of formula (I) may be particularly useful as an active material in a Na-ion battery.

This positive electrode active substance for a non-aqueous electrolyte secondary battery contains a lithium-transition metal composite oxide which has a crystal structure belonging to the space group Fm-3m and is represented by the compositional formula Li.sub.xMn.sub.yM.sub.aO.sub.bF.sub.c (in the formula: M is at least one type of metal element excluding Mn; x+y+a=b+c=2; 1<x≤1.35; 0.4≤y≤0.9; 0≤a≤0.2; and 1.3≤b≤1.8). In addition, the lattice constant a of the lithium-transition metal composite oxide is 4.09-4.16.

In a method of recovering an active metal of a lithium secondary battery, a cathode active material mixture is prepared from a waste cathode of a lithium secondary. The cathode active material mixture is reacted with a reductive reaction gas to form a preliminary precursor mixture having a reduction degree of transition metal defined by Equation 1 in a range from 0.24 to 1.6. A lithium precursor is recovered from the preliminary precursor mixture. A lithium recovery rationis improved by adjusting the reduction degree of transition metal.