Determining the age of an electrochemical energy storage unit
Various embodiments include a method for determining the age of an electrochemical energy storage unit comprising: referring to a first open-circuit voltage curve of the electrochemical energy storage unit dependent upon the state of charge of the electrochemical energy storage unit as a reference; ascertaining a second open-circuit voltage curve of the electrochemical energy storage unit dependent upon the state of charge of the electrochemical energy storage unit; and determining the age of the electrochemical energy storage unit by comparing the first and second open-circuit voltage curves.
1. An electrochemical energy storage unit comprising:
a measuring device; and
a computing device including a processor;
wherein the computing device stores a first open-circuit voltage curve;
the measuring device determines a second open-circuit voltage curve; and
the computing device determines an age of the electrochemical energy storage unit by executing instructions, the instructions configuring the processor to:
refer to a first open-circuit voltage curve of the electrochemical energy storage unit dependent upon the state of charge of the electrochemical energy storage unit as a reference;
ascertain a second open-circuit voltage curve of the electrochemical energy storage unit dependent upon the state of charge of the electrochemical energy storage unit; and
determine the age of the electrochemical energy storage unit by comparing the first and second open-circuit voltage curves and applying a proportional factor to the result of the comparison.
2. The electrochemical energy storage unit as claimed in claim 1 , further comprising at least one storage selected from the group consisting of: a lithium-ion battery, a lead-acid battery, a nickel battery, a redox flow battery, and a capacitor.
3. The electrochemical energy storage unit as claimed in claim 1 , wherein comparing the first open-circuit voltage curve and the second open-circuit voltage curve includes determining an area between the first open-circuit voltage curve and the second open-circuit voltage curve.
4. The electrochemical energy storage unit as claimed in claim 3 , wherein determining the area includes calculating an integral, wherein the lower limit of the integral is determined by an intersection point of the two open-circuit voltage curves and the upper limit of the integral is determined by at least one value for the state of charge.
5. An aircraft comprising:
an electrochemical energy storage unit for driving the aircraft;
a measuring device; and
a computing device including a processor;
wherein the computing device stores a first open-circuit voltage curve;
the measuring device determines a second open-circuit voltage curve; and
the computing device determines an age of the electrochemical energy storage unit by executing instructions, the instructions configuring the processor to:
refer to a first open-circuit voltage curve of the electrochemical energy storage unit dependent upon the state of charge of the electrochemical energy storage unit as a reference;
ascertain a second open-circuit voltage curve of the electrochemical energy storage unit dependent upon the state of charge of the electrochemical energy storage unit; and
determine the age of the electrochemical energy storage unit by comparing the first and second open-circuit voltage curves and applying a factor to the result of the comparison.
6. The aircraft as claimed in claim 5 , characterized in that the electrochemical energy storage unit propels the aircraft.
7. The aircraft as claimed in claim 5 , wherein comparing the first open-circuit voltage curve and the second open-circuit voltage curve includes determining an area between the first open-circuit voltage curve and the second open-circuit voltage curve.
8. The aircraft as claimed in claim 5 , wherein determining the area includes calculating an integral, wherein the lower limit of the integral is determined by an intersection point of the two open-circuit voltage curves and the upper limit of the integral is determined by at least one value for the state of charge.