Patent ID: 8039143

Claim:
An electrode unit for a prismatic battery comprising an electrode group in which positive electrode plates and negative electrode plates in an almost rectangular shape having four sides are alternately stacked with separators interposed therebetween, wherein each of positive electrode plates and negative electrode plates has an active material filled portion in which an active material is filled and core material exposed portions in which the active material is not filled, wherein said core material exposed portions are formed on two adjacent side edges of the four sides which are outside the active material in each of said positive electrode plates and negative electrode plates, and wherein said positive electrode plates and negative electrode plates are stacked such that the active material filled portions thereof overlap each other in the stack direction while the core material exposed portions thereof are directed not to overlap each other in the stack direction, said electrode unit further comprising: a positive current collector being in contact along the outside end surfaces of the two adjacent side edges comprising the core material exposed portions in the four side edges of all of the positive electrode plates; and a negative current collector having a cross section in an L-shape and being in contact along the outside end surfaces of the two adjacent side edges comprising the core material exposed portions in the four side edges of all of the negative electrode plates, not in contact with said positive current collector.