Batteries having desired working volume ratios of positive and negative materials

A method of making a lithium secondary battery comprising a battery case and an internal electrode body contained in the battery case and including a positive electrode comprising a foil of a first metal having a positive active material coated thereon, a negative electrode comprising a foil of a second metal having a negative active material coated thereon, and a separator made of porous polymer, the positive electrode and the negative electrode being wound or laminated so that the positive electrode and the negative electrode are not brought into direct contact with each other via the separator, the method comprising:

• testing a negative test cell made of a foil of said second metal having said negative active material coated thereon to determine a capacity of said negative test cell, said negative active material of said negative test cell having a negative active material weight;
• testing at least one positive test cell made of a foil of said first metal having said positive active material coated thereon to determine a weight of said positive active material at which said positive test cell has a capacity equal to said capacity of said negative test cell;
• calculating an experimental safe working volume ratio X3 equal to a ratio of said weight of said positive active material divided by said negative active material weight;
• forming a negative electrode sheet comprising a foil of said second metal having a layer of said negative active material formed thereon, said negative electrode sheet having a surface area A;
• forming a positive electrode sheet comprising a foil of said first metal having a layer of said positive active material formed thereon, said positive electrode sheet having a surface area A;
• removing from said negative electrode sheet a plurality of negative cells which each have an area a;
• removing from said positive electrode sheet a plurality of positive cells which each have an area a;
• calculating an average weight Wa−av of said negative cells;
• calculating an average weight Wc−av of said positive cells;
• calculating an average working volume ratio Xav equal to a ratio of said average weight Wc−av of said positive cells divided by said average weight Wa−av of said negative cells;
• calculating a value n equal to a ratio of said surface area A divided by said area a;
• and
• calculating a product of said value n times Q(u) where u equals a ratio Of (X3−Xav) divided by σ, where σ equals a ratio of (Wc−av2σc2+Wc−av2σa2) divided by Wc−av4, σa is a dispersion of the respective weights of said negative cells, and σc is a dispersion of the respective weights of said positive cells.