What is claimed is:
1. An eddy current sensor for inspecting internal cracks in a battery cell, comprising: a probe; a transmitting part disposed on the probe and having a structure in which a transmitting coil for inducing an eddy current in a battery cell to be evaluated is wound; and a receiving part disposed on the probe in a region spaced apart from the transmitting part and having a structure in which a receiving coil for detecting a signal change caused by the eddy current induced in the battery cell by the transmitting coil is wound, wherein the cross-sectional area (S1) of the transmitting part on which the transmitting coil is wound is larger than the cross-sectional area (R1) of the receiving part on which the receiving coil is wound.
2. The eddy current sensor according to claim 1, wherein a ratio of the cross-sectional area (S1) of the transmitting part to the cross-sectional area (R1) of the receiving part (S1:R1) is in a range of 1.5:1 to 10:1.
3. The eddy current sensor according to claim 1, wherein a ratio of the width (S2) of the transmitting part to the width (R2) of the receiving part (S2:R2) is in a range of 1.5:1 to 10:1.
4. The eddy current sensor according to claim 1, wherein the width (S2) of the transmitting part is in a range of 1 to 100 mm and corresponds to the length (L) of a battery cell evaluation area.
5. The eddy current sensor according to claim 1, wherein the width (R2) of the receiving part is in a range of 0.5 to 70 mm.
6. The eddy current sensor according to claim 1, wherein the transmitting part and the receiving part have a structure in which they are spaced apart from each other by a distance in a range of 1 to 50 mm.
7. The eddy current sensor according to claim 1, wherein the transmitting part and the receiving part each have a structure in which a winding groove is formed in a region where the transmitting coil and the receiving coil are respectively wound.
8. The eddy current sensor according to claim 1, wherein a diameter of the transmitting coil and the receiving coil is in a range of 0.02 to 10 mm.
9. A crack detection system for a battery cell, comprising: the eddy current sensor according to claim 1; a signal receiving unit for receiving a signal measured by the eddy current sensor; and a data processing unit for determining whether there is a crack in the battery cell to be evaluated based on a distribution of amplitude and phase difference of the signal received by the receiving unit.
10. The crack detection system for a battery cell according to claim 9, further comprising an output unit for outputting a result value determined by the data processing unit and a storage unit for storing the result value.
Detailed Description of the Invention
TECHNICAL FIELD
The present invention relates to an eddy current sensor for inspecting cracks in a battery cell and a crack detection system for a battery cell including the same.