Method for estimating SOC-OCV profile by degradation of secondary battery

A method for estimating an SOC-OCV profile by degradation of a secondary battery of an electronic apparatus, the method comprising:

• individually obtaining a first SOC-OCV profile of a cathode of the secondary battery and a second SOC-OCV profile of an anode of the secondary battery by measuring an open circuit voltage (OCV) of the cathode and the anode caused by a change in ain each state of charge (SOC) using a half cell, wherein the half cell is a cell provided with only one of a cathode and the anode;
• obtaining a third SOC-OCV profile of the cathode by reflecting a level of degradation by use of the secondary battery to modify the first SOC-OCV profile of the cathode, but setting only an SOC range to be narrow in proportion to the level of degradation while maintaining an OCV range of the cathode as it is;
• obtaining a fourth SOC-OCV profile of the anode by migrating the second SOC-OCV profile of the anode in a horizontal direction taking into account the level of degradation by use of the secondary battery;
• obtaining a fifth SOC-OCV profile of a full cell of the secondary battery by determining a subtraction of an OCV value by the SOC-OCV profile of the anode from an OCV value by the SOC-OCV profile of the cathode as an OCV value of the secondary battery;
• providing information on a remaining usable amount of battery based on the fifth SOC-OCV profile to the electronic apparatus;
• and
• initiating charging and discharging of the secondary battery using the fifth SOC-OCV profile,
• wherein the cathode material comprises Li1+xNiaCobMncO2, x≥0;
• a=b=c=⅓,
• wherein the anode material comprises graphite,
• wherein the OCV range of the cathode in the first profile and in the third profile are the same being 3.37V to 4.28V regardless of the level of degradation, and
• wherein the OCV range of the anode in the second profile is represented as 0.10V to 0.23V.