Method for detecting lithium plating, and method and device for managing battery by using same
Provided are a lithium plating detection method, a battery management method and apparatus for safety diagnosis using the lithium plating detection method. The lithium plating detection method according to the present disclosure includes detecting, accumulating and tracking each of an open circuit voltage (OCV) after fully charging and an OCV after fully discharging of a battery every charge/discharge cycle of the battery, and determining if lithium plating took place in the battery using a result of tracking the OCV after fully charging and the OCV after fully discharging, wherein a range satisfying a condition of the reduced OCV after fully charging and the reduced OCV after fully discharging in the tracking result is determined as a range in which lithium plating starts to take place.
1 . A battery management apparatus comprising:
a detection unit configured to generate a detection by detecting an open circuit voltage (OCV) after fully charging after every charge cycle and an OCV after fully discharging after every discharge cycle of a battery for a plurality of charge and discharge cycles;
a storage unit configured to accumulate results of the detection by the detection unit; and
a determination unit configured to determine whether each of the OCV after fully charging and the OCV after fully discharging increases, reduces or is maintained by comparing a detected and recorded OCV after fully charging in one charge cycle with a newly detected and recorded OCV after fully charging in a charge cycle immediately after the one charge cycle, and comparing a detected and recorded OCV after fully discharging with a newly detected and recorded OCV after fully discharging in a discharge cycle immediately after the one discharge cycle,
wherein the determination unit determines that lithium plating starts to take place when OCV after fully charging in the charge cycle immediately after the one charge cycle and OCV after fully discharging in the discharge cycle immediately after the one discharge cycle are both reduced.
2 . The battery management apparatus according to claim 1 , wherein the determination unit generates a calculation by calculating a Coulomb efficiency every charge and discharge cycle of the battery,
the storage unit further accumulates the calculation by the determination unit, and the determination unit further determines whether the Coulomb efficiency increases, reduces or is maintained by comparing an immediately previous recorded Coulomb efficiency with a newly recorded Coulomb efficiency, and
the determination unit determines that lithium plating starts to take place when a condition of a reduced Coulomb efficiency is satisfied as well.
3 . The battery management apparatus according to claim 1 , wherein the battery is a battery mounted on an electric vehicle,
when it is determined that lithium plating starts to take place in the battery by the determination unit, a warning is provided to a user.
4 . The battery management apparatus according to claim 1 , wherein a lithium plating occurrence range is from a point in time at which lithium plating starts to take place to a point in time at which the OCV after fully charging and the OCV after fully discharging start to be maintained, and the determination unit determines that the battery is inoperable when (i) the OCV after fully charging reduces and (ii) the OCV after fully discharging increases by amounts greater than respective amounts of change in the lithium plating occurrence range.
5 . The battery management apparatus according to claim 2 , wherein a lithium plating occurrence range is from a point in time at which lithium plating starts to take place to a point in time at which the OCV after fully charging and the OCV after fully discharging are maintained, and the determination unit determines that the battery is inoperable when (i) the OCV after fully charging reduces, (ii) the OCV after fully discharging increases, and (iii) the Coulomb efficiency reduces by amounts greater than respective amounts of change in the lithium plating occurrence range.
6 . The battery management apparatus according to claim 1 , wherein when discharging ends before the battery is fully discharged, the detection unit detects the OCV after the discharging ends, estimates the OCV after fully discharging by extrapolation and records the same.
7 . The battery management apparatus according to claim 4 , wherein when the battery is determined to be inoperable by the determination unit, the charging of the battery is stopped.
8 . The battery management apparatus according to claim 2 , wherein the battery is a battery mounted on an electric vehicle,
when it is determined that lithium plating starts to take place in the battery by the determination unit, a warning is provided to a user.
9 . The battery management apparatus according to claim 5 , wherein when the battery is determined to be inoperable by the determination unit, the charging of the battery is stopped.