The purpose of the present invention is to provide an active material for a secondary battery electrode, the active material having excellent rate characteristics and cycle resistance. The present invention is an active material for a secondary battery electrode, the active material having an olivine-type crystal structure, while having a carbon layer on the surface, wherein the ratio of the average thickness of the carbon layer which is present on a plane that is perpendicular to the crystal b-axis to the average thickness of the carbon layer which is present on a plane that is not perpendicular to the b-axis is from 0.30 to 0.80.

A positive electrode material and a preparation method therefor, a lithium-ion battery, and an electric vehicle. The positive electrode material comprises: matrix particles, materials forming the matrix particles comprising at least one of a lithium-rich manganese-based material, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium iron phosphate, lithium manganate, lithium nickel cobalt manganese aluminate, and lithium nickel manganate; and a housing, the housing covering at least a portion of the outer surfaces of the matrix particles.

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.

The present invention provides a silicon-silicon composite oxide-carbon composite, a method for preparing same, and a negative electrode active material for a lithium secondary battery, comprising same. More particularly, the silicon-silicon composite oxide-carbon composite of the present invention has a core-shell structure wherein the core comprises silicon, a silicon oxide compound, and magnesium silicate, and the shell comprises a carbon layer. In addition, by having a specific range of span values through the adjustment of particle size distribution of the composite, when used as a negative electrode active material of a secondary battery, the composite can improve not only the capacity of the secondary battery but also the cycle characteristics and initial efficiency thereof.

A battery pack including heterogeneous secondary batteries includes: a first battery set in which a plurality of first secondary batteries are stacked; and a second battery set in which a plurality of second secondary batteries are stacked, in which each of the first battery set and the second battery set is formed of a plurality, and the battery pack has an arrangement structure in which the plurality of first battery sets and the plurality of second battery sets are alternately stacked in one direction.

The present application relates to a battery module, which includes a first type of battery cells and a second type of battery cells electrically connected in series. The first type of battery cells and the second type of battery cells are battery cells with different chemical systems. The first type of battery cells includes N first battery cells, and the second type of battery cells includes M second battery cells, where N and M are greater than or equal one. The present application also relates to a battery pack and an electric apparatus including the battery module, and method and device for manufacturing the battery module.

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.

The process of making a lithium ion battery cathode comprises the step of forming a slurry of an active material, a nano-size conductive agent, a binder polymer, a solvent and a dispersant. The solvent consists essentially of one or more of a compound of Formula 1, 2, or 3, and the dispersant comprises an ethyl cellulose.

A lithium cobalt-based oxide cathode active material powder having: —a primary phase comprising Li, Co, and O, and —a secondary phase comprising LiNaSO.sub.4, wherein the content of said LiNaSO.sub.4 secondary phase in said powder is of at least 0.4 wt. % and inferior or equal to 1.1 wt. % with respect to a total weight of the cathode active material powder, said cathode active material powder being characterized in that it has a S/Na atomic ratio superior or equal to 0.80 and inferior or equal to 1.20.

An electrode plate includes a current collector, a first active substance layer, a second active substance layer, and an insulation layer. The current collector includes a first surface, the first active substance layer includes a first active substance, and the second active substance layer includes a second active substance. The first active substance layer is sandwiched between the current collector and the second active substance layer and covers a first portion of the first surface, the insulation layer covers a second portion of the first surface, and the first active substance layer and the insulation layer are stacked to form an overlapped portion in a length direction of the electrode plate. The current collector can be covered by a high-resistance layer, thereby improving safety performance of the electrochemical apparatus and the electronic apparatus.