Electrode Assembly, Lithium Secondary Battery Including Same, Method for Manufacturing Electrode Assembly, and Method for Managing Electrode Sliding Standard

An electrode assembly manufacturing method comprising:

• preparing an electrode sheet comprising:
• an electrode mixture applied part to which an electrode mixture is applied on an electrode current collector sheet, and an electrode mixture non-applied part to which an electrode mixture is not applied and is located at least at one edge of the electrode mixture applied part;
• performing a thickness measurement process comprising:
• measuring a thickness of each electrode mixture layer at a plurality of points selected at a boundary part of the electrode mixture applied part and the electrode mixture non-applied part, and measuring a thickness of an electrode mixture layer at a center part of the electrode mixture applied part;
• calculating an electrode thickness ratio comprising:
• calculating a ratio of a thickness of an electrode mixture layer at each of the plurality of points, to a thickness of an electrode mixture layer at a center part of the electrode mixture applied part;
• setting up a positive/negative electrode notching predetermined line that sets a notching predetermined line notching in the form of individual positive electrodes and individual negative electrodes, on positive electrode sheets and negative electrode sheets, based on calculated positive electrode thickness ratio values and negative electrode thickness ratio values;
• performing a notching process that notches according to the set notching predetermined line;
• and
• performing a lamination process of laminating by interposing a separator between the notched positive electrode and negative electrode,
• wherein
• the positive/negative electrode notching predetermined line setting process comprises:
• determining a positive electrode first face-to-face predetermined line P3 on the positive electrode sheet and determining a negative electrode face-to-face predetermined line P1 on the negative electrode sheet;
• determining the positive electrode first face-to-face predetermined line P3 as a positive electrode lower end part notching predetermined line;
• and
• determining a negative electrode upper end part notching predetermined line based on the negative electrode first face-to-face predetermined line P1,
• wherein
• the negative electrode first face-to-face predetermined line P1 and the positive electrode first face-to-face predetermined line P3 are determined such that a negative electrode thickness ratio at the negative electrode first face-to-face predetermined line P1 and a positive electrode thickness ratio at the positive electrode first face-to-face predetermined line P3 satisfy Condition 3 below;
• Negative electrode thickness ratio≥(Positive electrode thickness ratio/NP Ratio)×100.1 [Condition 3]
• wherein in the Condition 3, the NP Ratio is a ratio value of negative electrode capacity to positive electrode capacity per unit area, and is a preset value.

A method of managing sliding standards of an electrode including a sliding region in which a thickness of an electrode mixture layer gradually decreases to form an inclined plane with respect to a current collector plane, the method comprising:

• measuring a thickness TPC of a positive electrode mixture layer at the center part of a positive electrode, and a thickness TP1 of the positive electrode mixture layer at a lower end part predetermined area of the positive electrode, on a positive electrode sheet, respectively, and
• calculating a first positive electrode thickness ratio RTP1(=TP1/TPC), which is a ratio of TP1 to TPC;
• determining a negative electrode first face-to-face predetermined line P1 on a negative electrode sheet to face the lower end part predetermined area of the positive electrode;
• measuring a thickness TNC of a negative electrode mixture layer at a center part of a negative electrode and a thickness TN1 of the negative electrode mixture layer at the negative electrode first face-to-face predetermined line P1, on the negative electrode sheet, respectively, and calculating a first negative electrode thickness ratio RTN1(=TN1/TNc), which is a ratio of TN1 to TNC;
• and
• confirming whether a relationship between the first positive electrode thickness ratio RTP1 and the first negative electrode thickness ratio RTN1 satisfies Condition 1 below;
• R
• ⁢
• T
• N
• ⁢
• 1
• ≥
• (
• R
• ⁢
• T
• P
• ⁢
• 1
• /
• NP
• ⁢
• Ratio
• )
• ×
• 100.1
• [
• Condition
• ⁢
• 1
• ]
• in the Condition 1, the NP Ratio is a the ratio value of negative electrode capacity to positive electrode capacity per unit area, and is a preset value.