On-line estimation method of battery state of health in wide temperature range based on “standardized temperature”

An on-line State of Health estimation method for a battery in a wide temperature range comprising the following steps:

• S1. generating a plurality of incremental capacity curves for a battery based on a plurality of charging curves for the battery, wherein each of the charging curves for the battery is obtained by holding the battery for 2 hours at fixed ambient temperatures of −5° C. 0° C. 5° C. 10° C. 15° C. 20° C. 25° C. 30° C. 35° C. 40° C. 45° C. 50° C. 55° C. and then charging each battery with 0.1 C to obtain the charging curve at each of the fixed ambient temperatures for the battery;
• S2. selecting a temperature-sensitive feature point for each of the incremental capacity curves of the battery at different fixed ambient temperatures, wherein the temperature-sensitive feature point is a second inflection point of the incremental capacity curve, and determining a quantitative relationship between g voltage shift of the temperature-sensitive feature point and each fixed ambient temperature other than 25° C. based on the temperature of the battery at 25° C. by subtracting a voltage at the temperature-sensitive feature point for the battery at 25° C. from a voltage of the temperature-sensitive feature point of the battery at a temperature other than 25° C. and applying an Arrhenius fitting function to determine the quantitative relationship from (1):
• y
• =
• a
• ⁢
• ⁢
• exp
• ⁡
• (
• b
• T
• )
• +
• c
• (
• 1
• )
• wherein a, b, c are fitting parameters, T is a temperature, and y represents a voltage shift of temperature-sensitive feature point;
• S3. performing a standardized transformation of the incremental capacity curves at different temperatures;
• and
• S4. establishing a quantitative relationship between a transformed height of a capacity-sensitive feature point and a State of Health of the battery based on a BOX-COX transformation.