Battery module of improved connection reliability and battery pack employed with the same

A battery module comprising a plurality of unit modules, based on battery cells which can be charged and discharged, electrically connected to each other, wherein the unit modules are electrically connected to a bus bar in series and/or in parallel, the battery module has two or more electrical connection points, a first electrically connected member and a second electrically connected member facing each other are electrically connected to each other via a first electrical connection point, and a third electrically connected member facing the first electrically connected member or the second electrically connected member is electrically connected to the first electrically connected member or the second electrically connected member via a second electrical connection point,

• wherein the number of electrically connected members at each of the electrical connection points is less than the total number of the electrically connected members of the battery module,
• wherein the first electrical connection point or the second electrical connection point is formed by directly welding an electrode terminal of the one unit module to the bus bar and another electrical connection point is formed by welding between the electrode terminals of adjacent unit modules such that the electrical connection points sequentially deviate so as to not overlap each other, and
• wherein, of the plurality of unit modules, the bus bar is directly connected to only one unit module of the plurality of unit modules.

A manufacturing method of a battery module configured to have a structure in which unit modules are electrically connected to a bus bar in a state in which the unit modules are sequentially stacked, the manufacturing method comprising:

• in a structure in which electrode terminals of n unit modules are electrically connected to one bus bar in a state in which the electrode terminals of the n unit modules are electrically connected to each other,
• (a) connecting an electrode terminal of an uppermost unit module (first unit module) of the stacked unit modules to an electrode terminal of a second unit module stacked adjacent to the first unit module to form a first electrical connection point;
• (b) connecting the electrode terminal of the second unit module to an electrode terminal of a third unit module stacked adjacent to the second unit module at a position sequentially deviating from the first electrical connection point to form a second electrical connection point that does not overlap with the first electrical connection point;
• (c) repeatedly performing the step (b) to electrically interconnect electrode terminals of n unit modules such that an (n−1)-th electrical connection point is formed;
• and
• (d) connecting an electrode terminal of an n-th unit module to a bus bar contacting the n-th unit module while being adjacent to the n-th unit module at a position deviating from the (n−1)-th electrical connection point to form an n-th electrical connection point,
• wherein, of the n unit modules, the bus bar is directly connected to only the n-th unit module, and
• wherein the number of electrode terminals at each of the electrical connection points is less than the total number of the electrode terminals of the battery module.