The present application belongs to battery materials, and in particular, to a lithium-containing multi-phosphate cathode material and a preparation method therefor, and a secondary battery. The lithium-containing multi-phosphate cathode material includes a single-core multi-shell lithium manganese iron phosphate composite material, the composite material includes a core of lithium iron phosphate or lithium manganese iron phosphate, N lithium manganese iron phosphate coating layers coated on an outer surface of the core, and a carbon coating layer coated on an outermost layer of the composite material; N is an integer greater than or equal to 1; a manganese content in the N lithium manganese iron phosphate coating layers successively increases in a radially outward direction, and a particle size of the lithium manganese iron phosphate particles in the N lithium manganese iron phosphate coating layers successively decreases in the radially outward direction.

A method for forming a cathode includes milling a suspension of precursors via a micromedia mill to form a mixture of primary particles in the suspension. The precursors include one or more metal compounds. The method includes spray drying the suspension after the milling to form secondary particles. The secondary particles are agglomerations of the primary particles. The method also includes annealing the secondary particles to form a disordered rocksalt powder.

A method of removing hydrogen sulfide from a subterranean geological formation includes injecting a drilling fluid suspension in the subterranean geological formation. The drilling fluid suspension has a pH of 10 or more and includes a layered triple hydroxide material, including manganese, copper, and aluminum, in an amount of 0.01 to 1.5 percent by weight of the drilling fluid suspension. The method further includes circulating the drilling fluid suspension in the subterranean geological formation and forming a water-based mud and scavenging the hydrogen sulfide from the subterranean geological formation by reacting the hydrogen sulfide with the layered triple hydroxide material in the water-based mud.

According to one embodiment, a nonaqueous electrolyte battery includes a positive electrode, a negative electrode and a nonaqueous electrolyte. The positive electrode includes a first positive electrode active material which is represented by general formula LiMSO.sub.4F (M is at least one kind of element selected from the group consisting of Fe, Mn and Zn) and has a triplite type crystal structure, and a second positive electrode active material which is represented by general formula LiMSO.sub.4F (M is at least one kind of element selected from the group consisting of Fe, Mn and Zn) and has a tavorite type crystal structure.

A method for delithiating a lithium and transition metal nitride. The method involves mixing an oxidising agent with the lithium and transition metal nitride and recovering the material obtained. The transition metal may be Mn, Fe, Co, Ni, Cu, or a mixture thereof. The material obtained by the method may be used as a negative electrode material for a lithium-ion battery.

A composition used for forming a PZT-based piezoelectric film formed of Mn and Nb co-doped composite metal oxides is provided, in which the composition includes PZT-based precursors so that a metal atom ratio (Pb:Mn:Nb:Zr:Ti) in the composition satisfies (1.00 to 1.25):(0.002 to 0.056):(0.002 to 0.056):(0.40 to 0.60):(0.40 to 0.60), a rate of Mn is from 0.20 to 0.80 when the total of metal atom rates of Mn and Nb is 1, a rate of Zr is from 0.40 to 0.60 when the total of metal atom rates of Zr and Ti is 1, and the total rate of Zr and Ti is from 0.9300 to 0.9902 when the total of metal atom rates of Mn, Nb, Zr, and Ti is 1.

[Summary] A positive electrode active material is provided to contain: a solid solution lithium-containing transition metal oxide (A) represented by Li.sub.1.5[Ni.sub.aCo.sub.bMn.sub.c[Li].sub.d]O.sub.3 (where a, b, c and d satisfy the relations of a+b+c+d=1.5, 0.1<d0.4, 1.1a+b+c<1.4, 0.2a0.7 and 0<b/a<1); and a lithium-containing transition metal oxide (B) represented by LiM.sub.XMn.sub.2XO.sub.4 (where M represents Cr or Al, and x satisfies the relation of 0x<2).

The invention relates to electrodes that contain active materials of the formula: Na.sub.aX.sub.bM.sub.cM.sub.d(condensed polyanion).sub.e(anion).sub.f; where X is one or more of Na+, Li+ and K+; M is one or more transition metals; M is one or more non-transition metals; and where a>b; c>0; d0; e1 and f0. Such electrodes are useful in, for example, sodium ion battery applications.

An oxide represented by Formula 1:
(Sr.sub.2xA.sub.x)(M.sub.1yQ.sub.y)D.sub.2O.sub.7+d,Formula 1
wherein A is barium (Ba), M is at least one selected from magnesium (Mg) and calcium (Ca), Q is a Group 13 element, D is at least one selected from silicon (Si) and germanium (Ge), 0x2.0, 0<y1.0, and d is a value which makes the oxide electrically neutral.

Provided is a cerium-zirconium-based composite oxide having an excellent OSC, high catalytic activity, and excellent heat resistance, and also provided is a method for producing the same. The cerium-zirconium-based composite oxide comprises cerium, zirconium, and a third element other than these elements. The third element is (a) a transition metal element or (b) at least one or more elements selected from the group consisting of rare earth elements and alkaline earth metal elements. After a heat treatment at 1,000 C. to 1,100 C. for 3 hours, (1) the composite oxide has a crystal structure containing a pyrochlore phase, (2) a value of {I111/(I111+I222)}100 is 1 or more, and (3) the composite oxide has an oxygen storage capacity at 600 C. of 0.05 mmol/g or more, and an oxygen storage capacity at 750 C. of 0.3 mmol/g or more.