A cobalt-free layered positive electrode material, a preparation method thereof, and a lithium-ion battery are provided. The method includes: preparing a layered lithium nickel manganese oxide matrix material; mixing the layered lithium nickel manganese oxide matrix material with a coating agent to obtain a first mixed material; and forming a coating layer on a surface of the layered lithium nickel manganese oxide matrix material by performing a first sintering treatment on the first mixed material to obtain the cobalt-free layered positive electrode material. The coating agent includes a first coating agent including ceramic oxide, and a second coating agent including at least one of phosphate and silicate.

An electrode sheet includes a current collector and a first active material layer on a first surface of the current collector. The first active material layer includes a main portion and a first buffer portion. The main portion includes a first inner surface and an outer surface. The first inner surface is attached to the current collector, and the outer surface is parallel to the first inner surface. The first active material layer has a height that is a vertical distance from the outer surface to the first inner surface. The first buffer portion includes a second inner surface, a buffer surface, and an inner wall surface defining a first groove. A first end of the buffer surface is connected to the outer surface, a second end of the buffer surface is connected to the inner wall surface. The inner wall surface is shorter than the first active material layer.

Secondary batteries using lithium cobalt oxide as positive electrode active materials have a problem of a decrease in battery capacity due to repeated charging/discharging, for example. A positive electrode active material particle which hardly deteriorates is provided. In a first step, a container in which a lithium oxide and a fluoride are set is placed in a heating furnace, and in a second step, the inside of the heating furnace is heated in an atmosphere containing oxygen. The heating temperature of the second step is from 750° C. to 950° C., inclusive. By the manufacturing method, fluorine can be contained in the positive electrode active material particle to increase the wettability of the surface of the positive electrode active material so that the surface of the positive electrode active material is homogenized and planarized. The crystal structure of the thus manufactured positive electrode active material is unlikely to be broken in repeated high-voltage charging/discharging. Thus, secondary batteries using the positive electrode active material having such a feature have greatly improved cycle characteristics.

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.

The present invention is related to a manufacturing method of a negative active material for a lithium secondary battery, a negative active material for a lithium secondary battery manufactured by the method, and a lithium secondary battery including the same. According to one embodiment, it is provided that: a method of manufacturing a negative active material for lithium secondary battery, comprising: coating a negative active material precursor containing Si with crude tar or soft pitch; and annealing an obtained coating product, wherein, the crude tar contains a low molecular weight component that can be removed by a distillation process in an amount of 20 wt % or less.

An electrode rolling apparatus a for rolling an electrode substrate having a coated portion and an uncoated portion includes a coil section having an effective region where a uniform magnetic field is generated; and an electrode rolling section for rolling the electrode substrate, wherein the coated portion and the uncoated portion each comprise a plurality of pattern portions, the uncoated portion comprising a first uncoated pattern portion located on at least one end of opposing ends of the electrode substrate and a second uncoated pattern portion located between coated pattern portions, wherein the coil section comprises a first coil section for heating the first uncoated pattern portion, and a second coil section for heating the second uncoated pattern portion, and wherein a heating temperature of the second coil section is lower than a heating temperature of the first coil section.

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.

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.

A method for forming a treated sintered composition includes: providing a slurry precursor including a lithium-, sodium-, or magnesium-based compound; tape casting the slurry precursor to form a green tape; sintering the green tape at a temperature in a range of 500° C. to 1350° C. for a time in a range of less than 60 min to form a sintered composition; and heat treating the sintered composition at a temperature in a range of 700° C. to 1100° C. for a time in a range of 1 min to 2 hrs in an oxygen-containing atmosphere to form the treated sintered composition.

The invention relates to a method for producing an electrochemical cell comprising at least one porous electrode (2′), the method comprising at least the following method steps: (a) providing an electrode composition in the form of a homogeneous mixture comprising (i) at least one particulate active material (3); (ii) at least one particulate binder (5); (iii) at least one particulate pore-forming agent (4); and (iv) optionally at least one conducting additive (6); (b) forming a mouldable mass from the electrode composition; (c) applying the electrode composition to at least one surface of a substrate (1) to obtain a compact electrode (2); (d) producing an electrochemical cell comprising at least one compact electrode (2) which comprises the electrode composition according to method step (a); and (e) heating the at least one compact electrode (2) to liquefy the at least one particulate pore-forming agent (4); and/or (f) bringing the compact electrode (2) into contact with at least one liquid electrolyte composition or at least one liquid constituent of an electrolyte composition for an electrochemical cell which is capable of at least partially dissolving the at least one particulate pore-forming agent (4) to obtain a porous electrode (2), wherein method steps (a), (b), (c), (d) and (e) are carried out substantially without solvents.