The present invention provides an electrode assembly in which a negative electrode coated with a negative electrode active material on a surface of a negative electrode collector, a separator, and a positive electrode coated with a positive electrode active material on a surface of a positive electrode collector are repeatedly laminated, the electrode assembly comprising: monocells in which the positive electrode, the separator, the negative electrode, and the separator are laminated, wherein at least two or more monocells are laminated, wherein, in any one of the monocells, an expansion part extending lengthily to one side is formed on the separators, and the expansion part of the separator surrounds the monocells laminated to be disposed at the outermost layers to fix the laminated monocells. Furthermore, the present invention provides an electrode assembly in which a negative electrode coated with a negative electrode active material on a surface of a negative electrode collector, a separator, and a positive electrode coated with a positive electrode active material on a surface of a positive electrode collector are repeatedly laminated, the electrode assembly comprising: monocells in which the positive electrode, the separator, the negative electrode, and the separator are sequentially laminated, wherein at least two or more monocells are laminated, wherein each of the two or more monocells of the monocells comprises a positive electrode extension part, in which a positive electrode collector extends lengthily to one side, and a negative electrode extension part, in which a negative electrode collector extends lengthily to the other side, and the positive electrode extension part and the negative electrode extension part are respectively bonded to a positive electrode extension part and a negative electrode extension part to fix the laminated monocells.

The present invention provides an electrode assembly in which a negative electrode coated with a negative electrode active material on a surface of a negative electrode collector, a separator, and a positive electrode coated with a positive electrode active material on a surface of a positive electrode collector are repeatedly laminated, the electrode assembly comprising: monocells in which the positive electrode, the separator, the negative electrode, and the separator are laminated, wherein at least two or more monocells are laminated, wherein, in any one of the monocells, an expansion part extending lengthily to one side is formed on the separators, and the expansion part of the separator surrounds the monocells laminated to be disposed at the outermost layers to fix the laminated monocells. Furthermore, the present invention provides an electrode assembly in which a negative electrode coated with a negative electrode active material on a surface of a negative electrode collector, a separator, and a positive electrode coated with a positive electrode active material on a surface of a positive electrode collector are repeatedly laminated, the electrode assembly comprising: monocells in which the positive electrode, the separator, the negative electrode, and the separator are sequentially laminated, wherein at least two or more monocells are laminated, wherein each of the two or more monocells of the monocells comprises a positive electrode extension part, in which a positive electrode collector extends lengthily to one side, and a negative electrode extension part, in which a negative electrode collector extends lengthily to the other side, and the positive electrode extension part and the negative electrode extension part are respectively bonded to a positive electrode extension part and a negative electrode extension part to fix the laminated monocells.

What is provided is a solid state battery and a solid state battery manufacturing method capable of more reliably preventing short-circuiting. A solid state battery includes: a first electrode piece in which a first electrode active material layer is formed on a first current collector layer; a second electrode piece in which a second electrode active material layer is formed on a second current collector layer; and a bag-shaped solid electrolyte layer which accommodates the first electrode piece, wherein the first electrode piece accommodated in the bag-shaped solid electrolyte layer and the second electrode piece are laminated so as to overlap each other in a plan view so that the first electrode active material layer and the second electrode active material layer are disposed so as to face each other with the solid electrolyte layer interposed therebetween.

What is provided is a solid state battery and a solid state battery manufacturing method capable of more reliably preventing short-circuiting. A solid state battery includes: a first electrode piece in which a first electrode active material layer is formed on a first current collector layer; a second electrode piece in which a second electrode active material layer is formed on a second current collector layer; and a bag-shaped solid electrolyte layer which accommodates the first electrode piece, wherein the first electrode piece accommodated in the bag-shaped solid electrolyte layer and the second electrode piece are laminated so as to overlap each other in a plan view so that the first electrode active material layer and the second electrode active material layer are disposed so as to face each other with the solid electrolyte layer interposed therebetween.

A method for manufacturing an electrode assembly according to the present invention is a method for manufacturing an electrode assembly in which a negative electrode, a separator, and a positive electrode are repeatedly stacked, the method comprising: a unit cell manufacturing step of manufacturing a unit cell having a predetermined stack structure of the negative electrode, the separator, and the positive electrode; a film inserting step of inserting a film into a die; a unit cell stacking step of stacking the unit cell into the die; and an adhesive applying step of applying an adhesive between the stacked unit cell and the film within the die, wherein the unit cell stacking step and the adhesive applying step are repeatedly performed until stacking of predetermined unit cells is completed after the film inserting step. An electrode assembly assembled according to the manufacturing method is also disclosed.

A method for manufacturing an electrode assembly according to the present invention is a method for manufacturing an electrode assembly in which a negative electrode, a separator, and a positive electrode are repeatedly stacked, the method comprising: a unit cell manufacturing step of manufacturing a unit cell having a predetermined stack structure of the negative electrode, the separator, and the positive electrode; a film inserting step of inserting a film into a die; a unit cell stacking step of stacking the unit cell into the die; and an adhesive applying step of applying an adhesive between the stacked unit cell and the film within the die, wherein the unit cell stacking step and the adhesive applying step are repeatedly performed until stacking of predetermined unit cells is completed after the film inserting step. An electrode assembly assembled according to the manufacturing method is also disclosed.

An electrode assembly includes first and second electrode plate having opposite polarities, and a separator separating the first and second electrode plates. The first electrode plate includes two first stack sections and a bend section connecting the first stack sections and including a guide portion configured to guide the bend section to bend during production. The second electrode plate includes a second stack section disposed between the first stack sections. The separator includes two separation sections each disposed between the second stack section and one first stack section. Thickness Da of each first stack section, thickness Dc of the second stack section, and thickness Ds of each separation section in a stacking direction of the first stack sections, and a dimension w of the guide portion in a bending direction of the bend section satisfy: Dc+2Ds≤w≤2×(Dc+2Ds+Da).

An electrode assembly includes first and second electrode plate having opposite polarities, and a separator separating the first and second electrode plates. The first electrode plate includes two first stack sections and a bend section connecting the first stack sections and including a guide portion configured to guide the bend section to bend during production. The second electrode plate includes a second stack section disposed between the first stack sections. The separator includes two separation sections each disposed between the second stack section and one first stack section. Thickness Da of each first stack section, thickness Dc of the second stack section, and thickness Ds of each separation section in a stacking direction of the first stack sections, and a dimension w of the guide portion in a bending direction of the bend section satisfy: Dc+2Ds≤w≤2×(Dc+2Ds+Da).

A secondary battery includes a Z stack electrode assembly including a separator bent in a Z shape and including a plurality of bent areas, a first electrode plate on a lower portion of each of the bent areas, and a second electrode plate on an upper portion of each of the bent areas, and an exterior portion configured to accommodate the Z stack electrode assembly, and an outermost end area of the separator is bent to be thermally fused to a bent area of the plurality of bent areas of the separator.

A secondary battery includes a Z stack electrode assembly including a separator bent in a Z shape and including a plurality of bent areas, a first electrode plate on a lower portion of each of the bent areas, and a second electrode plate on an upper portion of each of the bent areas, and an exterior portion configured to accommodate the Z stack electrode assembly, and an outermost end area of the separator is bent to be thermally fused to a bent area of the plurality of bent areas of the separator.