Battery and method for manufacturing battery

Abstract

A manufacturing method of a battery including attaching a first current collector lead to a first electrode plate; attaching a second current collector lead to a second electrode plate; a step of fabricating a wound electrode group by winding the first electrode plate and the second electrode plate around a winding core member with a separator interposed therebetween; accommodating the wound electrode group in a closed-end cylindrical metal case being a first electrode terminal; joining the first current collector lead to an inner sidewall surface of the metal case (step X); joining the second current collector lead to a sealing member being a second electrode terminal; and sealing the metal case, before step X, a joint portion of the first current collector lead with the inner sidewall surface of the metal case is curved in a same direction as a curve of the inner sidewall surface of the metal case.

What is claimed is: 
     
         1 . A manufacturing method of a battery comprising:
 a step of attaching a first current collector lead to a first electrode plate;   a step of attaching a second current collector lead to a second electrode plate having polarity opposite to that of the first electrode plate;   a step of fabricating a wound electrode group by winding the first electrode plate and the second electrode plate around a winding core member with a separator interposed between the first and second electrode plates;   a step of accommodating the wound electrode group in a closed-end cylindrical metal case being a first electrode terminal;   a step X of joining the first current collector lead to an inner sidewall surface of the metal case;   a step of joining the second current collector lead to a sealing member being a second electrode terminal; and   a step of sealing the metal case by disposing an insulating member at an inner-surface side of an opening of the metal case, inserting the sealing member in a position of the opening in which the insulating member is disposed, and crimping the metal case to the sealing member, wherein   before the step X, a joint portion of the first current collector lead with the inner sidewall surface of the metal case is curved in a same direction as a curve of the inner sidewall surface of the metal case.   
     
     
         2 . A manufacturing method of a battery comprising:
 a step of attaching a first current collector lead to a first electrode plate;   a step of attaching a second current collector lead to a second electrode plate having polarity opposite to that of the first electrode plate;   a step of fabricating a wound electrode group by winding the first electrode plate and the second electrode plate around a winding core member with a separator interposed between the first and second electrode plates;   a step of accommodating the wound electrode group in a closed-end cylindrical metal case being a first electrode terminal;   a step X of joining the first current collector lead to an inner sidewall surface of the metal case;   a step of joining the second current collector lead to a sealing member being a second electrode terminal; and   a step of sealing the metal case by disposing an insulating member at an inner-surface side of an opening of the metal case, inserting the sealing member in a position of the opening in which the insulating member is disposed, and crimping the metal case around the sealing member, wherein   in the step X of joining, a joint portion of the first current collector lead with the inner sidewall surface of the metal case is curved in a same direction as a curve of the inner sidewall surface of the metal case.   
     
     
         3 . The manufacturing method of a battery of  claim 1 , wherein
 in the step of accommodating the wound electrode group in a closed-end cylindrical metal case being a first electrode metal,   the first current collector lead and the second current collector lead are accommodated to be located at the opening side of the metal case.   
     
     
         4 . The manufacturing method of a battery of  claim 1 , further comprising:
 after the step X and before the step of joining the second current collector lead to a sealing member being a second electrode terminal,   a step of locating an intermediate member on the wound electrode group.   
     
     
         5 . The manufacturing method of a battery of  claim 1 , further comprising:
 before the step of sealing,   a step of applying nonaqueous electrolyte fluid into the metal case by depressurization.   
     
     
         6 . The manufacturing method of a battery of  claim 1 , further comprising:
 a step of extracting the winding core from the wound electrode group,   the wound electrode group, from which the winding core has been extracted, being accommodated in the metal case.   
     
     
         7 . The manufacturing method of a battery of  claim 1 , wherein a thickness of the first current collector lead is 80 μm or less. 
     
     
         8 . The manufacturing method of a battery of  claim 1 , wherein a length of the first current collector lead in a circumferential direction of the wound electrode group ranges from 10% to 30%, both inclusive, of a length of an outer periphery of the wound electrode group. 
     
     
         9 . The manufacturing method of a battery of  claim 2 , wherein
 in the step of accommodating the wound electrode group in a closed-end cylindrical metal case being a first electrode metal,   the first current collector lead and the second current collector lead are accommodated to be located at the opening side of the metal case.   
     
     
         10 . The manufacturing method of a battery of  claim 2 , further comprising:
 after the step X and before the step of joining the second current collector lead to a sealing member being a second electrode terminal,   a step of locating an intermediate member on the wound electrode group.   
     
     
         11 . The manufacturing method of a battery of  claim 2 , further comprising:
 before the step of sealing,   a step of applying nonaqueous electrolyte fluid into the metal case by depressurization.   
     
     
         12 . The manufacturing method of a battery of  claim 2 , further comprising:
 a step of extracting the winding core from the wound electrode group,   the wound electrode group, from which the winding core has been extracted, being accommodated in the metal case.   
     
     
         13 . The manufacturing method of a battery of  claim 2 , wherein in the first current collector lead, a plurality of grooves extending along the center axis of the wound electrode group are formed. 
     
     
         14 . The manufacturing method of a battery of  claim 2 , wherein in the first current collector lead, a plurality of through-holes are open in a grid pattern. 
     
     
         15 . The manufacturing method of a battery of  claim 2 , wherein in the first current collector lead, a plurality of through-holes are open in a honeycomb pattern. 
     
     
         16 . The manufacturing method of a battery of  claim 2 , wherein a thickness of the first current collector lead is 80 μm or less. 
     
     
         17 . The manufacturing method of a battery of  claim 2 , wherein a length of the first current collector lead in a circumferential direction of the wound electrode group ranges from 10% to 30%, both inclusive, of a length of an outer periphery of the wound electrode group.