Method for improving capacity test accuracy of lithium ion battery

The invention, which relates to the technical field of lithium ion batteries, discloses a method for improving the capacity test accuracy of a lithium ion battery. The method comprises the following steps: step one, charging a lithium ion battery to a full charge state; step two, laying the charged lithium ion battery aside; step three, carrying out large-and-small-current-combined stagewise discharging on the lithium ion battery at an environment temperature T and measuring the discharge capacity of each stage; step four, setting a mathematical model of a total discharge capacity C0 of a standard discharge current A of the lithium ion battery to be: C0 = C1 + C2 +... C (n) + C (n+1) + C (n+1) * (a*T+b); and step five, determining determined values of a coefficient a and the a constant b and calculating the discharge capacity discharged based on the standard discharge current A in the batch production process through the mathematical model. Therefore, consumption of lots of energy fortemperature control in th