Lithium secondary battery

A lithium secondary battery, comprising:

• a bare cell having an electrode assembly and a case containing the electrode assembly, the bare cell comprising a plurality of major surfaces separated by a plurality of minor surfaces;
• a pair of electrode terminals extending from said electrode assembly to form two opposite polarities for said lithium secondary battery;
• a protection circuit board cutting off currents by detecting overheating or an overcharge, said protection circuit board being electrically connected to the bare cell and disposed on one of the plurality of the minor surfaces of the bare cell;
• an external terminal electrically connected to the protection circuit board;
• a hard cover covering at least the plurality of major surfaces of the bare cell, the hard cover comprising an inner surface facing towards the bare cell and an outer surface disposed opposite to the inner surface and facing away the bare cell;
• and
• a molded member exposing the external terminal and a portion of the protection circuit board with the portion being completely overlapped by the external terminal, covering said protection circuit board and completely covering at least two of the plurality of minor surfaces which are different from the one of the plurality of the minor surfaces on which the protection circuit board is disposed, the molded member not disposed between the bare cell and the inner surface of the hard cover,
• wherein said hard cover has a pair of cover components to cover the plurality of major surfaces of the bare cell,
• wherein said pair of cover components are first and second sub hard covers made of metal or resin,
• wherein each of the first and second sub hard covers has two side cover portions extending respectively from two opposite long side edges of wide surfaces of the each of the first and second sub hard covers and enclosing at least one of the plurality of minor surfaces of the bare cell,
• wherein the two side cover portions of the each of the first and second sub hard covers have notches along their longest edges, and
• wherein both of the side cover portions having the notches are engaged by overlapping.

A method for forming a lithium secondary battery, said method comprising:

• forming a bare cell by inserting an electrode assembly within a case and sealing said case, the bare cell comprising a plurality of major surfaces separated by a plurality of minor surfaces;
• assembling a core pack by connecting external terminals to first and second electrode taps connected to said electrode assembly and by connecting said external terminals to a protection circuit module supported by a protection circuit board;
• covering at least the plurality of major surfaces of the bare cell by a hard cover;
• and
• after the bare cell is covered by the hard cover, applying molding material through a mold to expose the external terminals and a portion of the protection circuit module with the portion being completely overlapped by the external terminal, and to cover said protection circuit module and to completely cover at least two of the plurality of minor surfaces which are different from the one of the plurality of the minor surfaces on which the protection circuit module is disposed.