A secondary battery includes a positive electrode, a negative electrode, and an electrolytic solution. The positive electrode includes a lithium-nickel composite oxide. The negative electrode includes a lithium-titanium composite oxide. The electrolytic solution includes a dinitrile compound and a carboxylic acid ester. A ratio of a capacity per unit area of the positive electrode to a capacity per unit area of the negative electrode is greater than or equal to 100% and less than or equal to 120%. A ratio of a number of moles of the dinitrile compound to a number of moles of the carboxylic acid ester is greater than or equal to 1% and less than or equal to 4%.

A secondary battery includes a positive electrode, a negative electrode, and an electrolytic solution. The positive electrode includes a lithium-nickel composite oxide. The negative electrode includes a lithium-titanium composite oxide. The electrolytic solution includes a dinitrile compound and a carboxylic acid ester. A ratio of a capacity per unit area of the positive electrode to a capacity per unit area of the negative electrode is greater than or equal to 100% and less than or equal to 120%. A ratio of a number of moles of the dinitrile compound to a number of moles of the carboxylic acid ester is greater than or equal to 1% and less than or equal to 4%.

A battery includes an electrode assembly; and a housing assembly made of a conductive material for accommodating the electrode assembly. The housing assembly includes a first housing and a second housing electrically insulated from each other. The electrode assembly includes a first electrode plate having a first current collector and a first active material layer; a second electrode plate having a second current collector and a second active material layer; and a separator. The first current collector includes a first blank foil region located at an edge region of the first current collector, extending from a winding start end toward a winding termination end of the first electrode plate and electrically connected to the first housing. The second current collector includes a second blank foil region located at a winding start end and/or a winding termination end of the second electrode plate; and electrically connected to the second housing.

A battery includes an electrode assembly; and a housing assembly made of a conductive material for accommodating the electrode assembly. The housing assembly includes a first housing and a second housing electrically insulated from each other. The electrode assembly includes a first electrode plate having a first current collector and a first active material layer; a second electrode plate having a second current collector and a second active material layer; and a separator. The first current collector includes a first blank foil region located at an edge region of the first current collector, extending from a winding start end toward a winding termination end of the first electrode plate and electrically connected to the first housing. The second current collector includes a second blank foil region located at a winding start end and/or a winding termination end of the second electrode plate; and electrically connected to the second housing.

A variable-diameter adsorption winding needle mechanism and a winding machine are provided. The variable-diameter adsorption winding needle mechanism includes a winding needle assembly, a first adsorption winding needle, a second adsorption winding needle and a pin assembly. A plurality of adsorption holes are provided on the outer peripheral surfaces of the first adsorption winding needle and the second adsorption winding needle. At the same time, the winding needle assembly is also used to drive, under the driving of the pin assembly, the first adsorption winding needle and the second adsorption winding needle to move close to or away from each other.

A variable-diameter adsorption winding needle mechanism and a winding machine are provided. The variable-diameter adsorption winding needle mechanism includes a winding needle assembly, a first adsorption winding needle, a second adsorption winding needle and a pin assembly. A plurality of adsorption holes are provided on the outer peripheral surfaces of the first adsorption winding needle and the second adsorption winding needle. At the same time, the winding needle assembly is also used to drive, under the driving of the pin assembly, the first adsorption winding needle and the second adsorption winding needle to move close to or away from each other.

A secondary battery includes: an electrode assembly including: a negative electrode plate; a positive electrode plate; and a separator interposed between the negative electrode plate and the positive electrode plate; a bond on one surface of the electrode assembly perpendicular to a surface of the separator to fix the separator; a case accommodating the electrode assembly; a negative electrode lead drawn out from the negative electrode plate; and a positive electrode lead drawn out from the positive electrode plate.

A secondary battery includes: an electrode assembly including: a negative electrode plate; a positive electrode plate; and a separator interposed between the negative electrode plate and the positive electrode plate; a bond on one surface of the electrode assembly perpendicular to a surface of the separator to fix the separator; a case accommodating the electrode assembly; a negative electrode lead drawn out from the negative electrode plate; and a positive electrode lead drawn out from the positive electrode plate.

A secondary battery includes an electrode assembly having a first electrode tab protruding from a first side of the electrode assembly and a second electrode tab protruding from a second side of the electrode assembly; a case accommodating the electrode assembly and having a first opening at one side of the case and a second opening at another side of the case; a first terminal electrically coupled to the first electrode tab of the electrode assembly; a first cap plate sealing the first opening of the case and exposing the first terminal to the outside; a second terminal electrically coupled to the second electrode tab of the electrode assembly; and a second cap plate sealing the second opening of the case and exposing the second terminal to the outside, wherein the first electrode tab and the second electrode tab have bent portions.

The present invention provides a battery, comprising a case, a cell packaged in the case, an electrical terminal located at one end of the case and electrically connected to the cell, a safety device and a current cut-off device. The safety device comprises a first and second electrode respectively electrically connected to a positive electrode or a negative electrode. The first electrode and the second electrode are arranged spaced apart from each other and form an electric field, and a gas generating material capable of generating an inert gas when a voltage reaches or exceeds a threshold value is provided in the electric field. The current cut-off device is electrically connected between the cell and the electrical terminal and is capable of causing a brake of circuit in response to a pressure difference between the inside and the outside of the battery caused by the inert gas.