Apparatus and method of testing performance of battery cell

An apparatus for nondestructively testing performance of a battery cell, the apparatus comprising:

• a memory configured to store first profile data, second profile data, a first positive electrode upper limit, a first positive electrode lower limit, a first negative electrode upper limit, and a first negative electrode lower limit that are determined in advance through a preliminary experiment with respect to each of a plurality of reference cells;
• a sensing unit configured to measure an open-circuit voltage of a test cell according to a variation in a state of charge (SOC) of the test cell;
• and
• a controller electrically connected to the memory and the sensing unit and configured to test performance of the test cell in a nondestructive manner,
• wherein the first profile data indicates a variation in an open-circuit voltage of a positive electrode of the reference cell according to a variation in an amount of lithium ions stored in the positive electrode of the reference cell,
• wherein the second profile data indicates a variation in an open-circuit voltage of a negative electrode of the reference cell according to a variation in an amount of lithium ions stored in the negative electrode of the reference cell,
• wherein the first positive electrode upper limit corresponds to the amount of lithium ions stored in the positive electrode of the reference cell at an upper limit within a predetermined SOC range,
• wherein the first positive electrode lower limit corresponds to the amount of lithium ions stored in the positive electrode of the reference cell at a lower limit within the predetermined SOC range,
• wherein the first negative electrode upper limit corresponds to the amount of lithium ions stored in the negative electrode of the reference cell at an upper limit within the predetermined SOC range, and
• wherein the first negative electrode lower limit corresponds to the amount of lithium ions stored in the negative electrode of the reference cell at a lower limit within the predetermined SOC range,
• wherein the controller is configured to:
• generate third profile data indicating a variation in the open-circuit voltage of each of the plurality of the reference cells with respect to the predetermined SOC range, based on the first profile data, the second profile data, the first positive electrode upper limit, the first positive electrode lower limit, the first negative electrode upper limit, and the first negative electrode lower limit;
• generate fourth profile data indicating a variation in an open-circuit voltage at opposite ends of the test cell with respect to the predetermined SOC range measured by the sensing unit;
• estimate a first test result including a second positive electrode upper limit and a second positive electrode lower limit of the test cell, and a second test result including a second negative electrode upper limit and a second negative electrode lower limit of the test cell, based on the third profile data and the fourth profile data;
• and
• wherein the second positive electrode upper limit corresponds to the amount of lithium ions stored in a positive electrode of the test cell at an upper limit within the predetermined SOC range,
• wherein the second positive electrode lower limit corresponds to an amount of lithium ions stored in the positive electrode of the test cell at a lower limit within the predetermined SOC range,
• wherein the second negative electrode upper limit corresponds to an amount of lithium ions stored in a negative electrode of the test cell at an upper limit within the predetermined SOC range,
• wherein the second negative electrode lower limit corresponds to an amount of lithium ions stored in the negative electrode of the test cell at a lower limit of the predetermined SOC range, and
• wherein the apparatus further comprises an output unit configured to output the first test result indicating performance of a positive electrode of the test cell and the second test result indicating performance of a negative electrode of the test cell.