According to an embodiment, there are provided a method for manufacturing a battery module for an electric vehicle and a battery module manufactured by the method. The method comprises preparing an electrode assembly, the electrode assembly including a plurality of electrode plates, a plurality of electrode tabs, and a separator, forming a plurality of electrode leads by friction-welding a copper piece and an aluminum piece, attaching a sealing film to each of the plurality of electrode leads, packing the electrode assembly in a pouch case, with the aluminum piece exposed to an outside of the pouch case, injecting an electrolyte into the pouch case, sealing the pouch case to form each of the plurality of battery cells, stacking the plurality of battery cells one over another, and connecting the aluminum pieces of the plurality of battery cells to each other via a sensing bus bar.

A film (200) includes a first accommodation portion (210) and a second accommodation portion (220). The first accommodation portion (210) covers one side of the battery element (100). The second accommodation portion (220) covers the other side opposite to the one side of the battery element (100). A recessed portion (232) is formed at a portion of the film (200) folded from one of the first accommodation portion (210) and the second accommodation portion (220) to the other. The recessed portion (232) is recessed towards the battery element (100). The recessed portion (232) extends along one direction orthogonal to a direction from the one side toward the other side of the battery element (100).

A film (200) includes a first accommodation portion (210) and a second accommodation portion (220). The first accommodation portion (210) covers one side of the battery element (100). The second accommodation portion (220) covers the other side opposite to the one side of the battery element (100). A recessed portion (232) is formed at a portion of the film (200) folded from one of the first accommodation portion (210) and the second accommodation portion (220) to the other. The recessed portion (232) is recessed towards the battery element (100). The recessed portion (232) extends along one direction orthogonal to a direction from the one side toward the other side of the battery element (100).

A secondary battery includes a positive electrode, a negative electrode, and an electrolytic solution including a carbonic acid ester compound.

A secondary battery may include an electrode assembly formed by alternately stacking an electrode and a separator; a battery case; a plurality of electrode tabs, each of which protrudes from the electrode assembly; a plurality of electrode leads, each of which has one end connected to the electrode tab and the other end protruding outward; a piezoelectric element which is disposed to the outside of a cup portion of the battery case that accommodates the electrode assembly and which, when the battery case expands in volume, receives pressure and supplies electric power to the outside; and a short-circuit inducing part which has a wire shape and both ends respectively positioned on sealing portions of the battery case that seal the electrode leads, wherein, when the electric power is applied from the piezoelectric element, both the ends respectively extend toward the electrode leads and come into contact with the electrode leads.

A secondary battery includes a positive electrode, a negative electrode, and an electrolytic solution. The positive electrode includes a positive electrode active material. The electrolytic solution includes a multi-nitrile compound. The positive electrode active material includes a lithium-nickel composite oxide and a boron compound. The lithium-nickel composite oxide has a layered rock-salt crystal structure. The positive electrode active material has a crystallite size of a (104) plane that is greater than or equal to 40.0 nm and less than or equal to 74.5 nm. The crystallite size is calculated by X-ray diffractometry and Scherrer equation. The positive electrode active material has an element concentration ratio that is greater than or equal to 0.15 and less than or equal to 0.90. The element concentration ratio is calculated on the basis of a B1s spectrum, a Ni2p.sub.3/2 spectrum, a Co2p.sub.3/2 spectrum, a Mn2p.sub.1/2 spectrum, and an Al2s spectrum of the positive electrode active material detected by X-ray photoelectron spectroscopy.

A secondary battery includes a positive electrode, a negative electrode, and an electrolytic solution. The positive electrode includes a positive electrode active material. The electrolytic solution includes a multi-nitrile compound. The positive electrode active material includes a lithium-nickel composite oxide and a boron compound. The lithium-nickel composite oxide has a layered rock-salt crystal structure. The positive electrode active material has a crystallite size of a (104) plane that is greater than or equal to 40.0 nm and less than or equal to 74.5 nm. The crystallite size is calculated by X-ray diffractometry and Scherrer equation. The positive electrode active material has an element concentration ratio that is greater than or equal to 0.15 and less than or equal to 0.90. The element concentration ratio is calculated on the basis of a B1s spectrum, a Ni2p.sub.3/2 spectrum, a Co2p.sub.3/2 spectrum, a Mn2p.sub.1/2 spectrum, and an Al2s spectrum of the positive electrode active material detected by X-ray photoelectron spectroscopy.

An electrochemical apparatus includes an electrode assembly, a packaging film, and a first tab, where the first tab is electrically connected to the electrode assembly, the packaging film includes a first packaging film and a second packaging film which are located at two sides of the first tab, the first packaging film includes a first sealing zone, the second packaging film includes a second sealing zone, and the first sealing zone and the second sealing zone are bonded to seal the electrode assembly. The first sealing zone includes a first region and a second region, the first region covers a projection of the first tab on the first sealing zone, the second region connects to the first region, and a width of the second region is less than that of the first region.

An electrochemical apparatus includes an electrode assembly, a packaging film, and a first tab, where the first tab is electrically connected to the electrode assembly, the packaging film includes a first packaging film and a second packaging film which are located at two sides of the first tab, the first packaging film includes a first sealing zone, the second packaging film includes a second sealing zone, and the first sealing zone and the second sealing zone are bonded to seal the electrode assembly. The first sealing zone includes a first region and a second region, the first region covers a projection of the first tab on the first sealing zone, the second region connects to the first region, and a width of the second region is less than that of the first region.

A battery cell includes an electrode assembly and a packaging bag for accommodating the electrode assembly and a first adhesive layer and a second adhesive layer. One end of the first adhesive layer and one end of the second adhesive layer are both adhered to the first surface of the electrode assembly, and the other end of the first adhesive layer and the other end of the second adhesive layer both extend to the bottom of the electrode assembly and are adhered to a second surface opposite the first surface, a surface on which a terminating end of the electrode assembly is defined as the first surface; and a third adhesive layer, one end of the third adhesive layer is adhered to the first adhesive layer, and the other end of the third adhesive layer is adhered to the second adhesive layer.