A main object of the present disclosure is to provide an all solid state battery in which occurrence of short circuit is inhibited. The present disclosure achieves the object by providing an all solid state battery comprising an anode including at least an anode current collector, a cathode, and a solid electrolyte layer arranged between the anode and the cathode; wherein a protective layer containing a Mg-containing particle that contains at least Mg, and also containing a polymer, is arranged between the anode current collector and the solid electrolyte layer; the solid electrolyte layer contains a solid electrolyte in a granular shape; and when X designates an average particle size D.sub.50 of the solid electrolyte and Y designates an average thickness of the solid electrolyte layer, X/Y is 0.0125 or more and 0.02 or less.

A main object of the present disclosure is to provide an all solid state battery in which occurrence of short circuit is inhibited. The present disclosure achieves the object by providing an all solid state battery comprising an anode including at least an anode current collector, a cathode, and a solid electrolyte layer arranged between the anode and the cathode; wherein a protective layer containing a Mg-containing particle that contains at least Mg, and also containing a polymer, is arranged between the anode current collector and the solid electrolyte layer; the solid electrolyte layer contains a solid electrolyte in a granular shape; and when X designates an average particle size D.sub.50 of the solid electrolyte and Y designates an average thickness of the solid electrolyte layer, X/Y is 0.0125 or more and 0.02 or less.

A secondary battery includes an electrode assembly having a negative electrode, a positive electrode tab protruding to a first side, a negative electrode tab protruding to a second side, and a through-hole; an upper can having a flat planar portion and a circumferential portion protruding in a vertical direction along an edge of the flat planar portion; a lower can having a flat planar portion and a circumferential portion protruding in the vertical direction along an edge of the flat planar portion; and a center pin configured to apply elastic force in the vertical direction when being inserted into the through-hole. The center pin applies the elastic force to allow the negative electrode tab to be in direct contact with the lower can and allow the positive electrode tab to be in direct contact with the upper can.

A secondary battery includes an electrode assembly having a negative electrode, a positive electrode tab protruding to a first side, a negative electrode tab protruding to a second side, and a through-hole; an upper can having a flat planar portion and a circumferential portion protruding in a vertical direction along an edge of the flat planar portion; a lower can having a flat planar portion and a circumferential portion protruding in the vertical direction along an edge of the flat planar portion; and a center pin configured to apply elastic force in the vertical direction when being inserted into the through-hole. The center pin applies the elastic force to allow the negative electrode tab to be in direct contact with the lower can and allow the positive electrode tab to be in direct contact with the upper can.

A battery pack includes a housing and multiple electrode core strings electrically connected to each other and disposed in the housing. The housing includes a housing body which includes sub-housings connected to each other. A sub-housing includes at least one reinforcing plate and a top plate and a bottom plate oppositely arranged in a first direction. The reinforcing plate is arranged between and is connected to the top plate and the bottom plate, and divides an interior of the corresponding sub-housing into multiple accommodating cavities. At least one accommodating cavity includes at least one electrode core string which includes electrode core assemblies connected and arranged in a second direction. The electrode core assemblies are disposed in an encapsulation film. A length of the electrode core string extends in the second direction. The housing includes a mounting component that is configured to be connected and fixed to an external load.

A battery pack includes a housing and multiple electrode core strings electrically connected to each other and disposed in the housing. The housing includes a housing body which includes sub-housings connected to each other. A sub-housing includes at least one reinforcing plate and a top plate and a bottom plate oppositely arranged in a first direction. The reinforcing plate is arranged between and is connected to the top plate and the bottom plate, and divides an interior of the corresponding sub-housing into multiple accommodating cavities. At least one accommodating cavity includes at least one electrode core string which includes electrode core assemblies connected and arranged in a second direction. The electrode core assemblies are disposed in an encapsulation film. A length of the electrode core string extends in the second direction. The housing includes a mounting component that is configured to be connected and fixed to an external load.

A composite porous membrane contains at least one porous base layer and at least one uniaxially stretched coating layer located on at least one side surface of the porous base layer. For example, the composite porous membrane comprises at least one porous base layer and at least one nanofiber-like non-polyolefin polymer porous layer oriented along the transverse stretching direction of the composite porous membrane and located on one or two side surfaces of the porous base layer, or the composite porous membrane comprises a biaxially stretched polypropylene porous base layer and a uniaxially stretched coating layer located on at least one side surface of the porous base layer. The composite porous membrane is coated with a coating solution prior to transversely stretching. The nanofiber-like non-polyolefin polymer porous layer may reduce cracking of the composite porous membrane in the machine direction.

Disclosed is a battery pack including a secondary battery and a circuit board, in which the secondary battery includes a metal exterior portion, a first external terminal, and a second external terminal, the circuit board has a plurality of connection portions connected to the first external terminal or the second external terminal, at least one of the connection portions has a first opening, and the connection portion having the first opening is solder-bonded to the first external terminal or the second external terminal.

Disclosed is a battery pack including a secondary battery and a circuit board, in which the secondary battery includes a metal exterior portion, a first external terminal, and a second external terminal, the circuit board has a plurality of connection portions connected to the first external terminal or the second external terminal, at least one of the connection portions has a first opening, and the connection portion having the first opening is solder-bonded to the first external terminal or the second external terminal.

The present disclosure provides a battery core assembly, a battery, a battery pack, and a vehicle. The battery core assembly includes an encapsulation film and an electrode core assembly encapsulated in the encapsulation film. The electrode core assembly includes an electrode core assembly body and two electrode lead-out members of opposite polarities electrically connected to the electrode core assembly body. The electrode core assembly body includes at least two electrode cores connected in parallel. Each of the electrode cores includes an electrode core body and two tabs of opposite polarities that are electrically connected to the electrode core body. The electrode core assembly body further includes a tab support. The two electrode lead-out members are respectively electrically connected to one of the tab supports located two sides of the electrode core assembly body in a first direction.