Page 23 - Shimadzu Journal vol.10 Issue1

Materials Science

the internal structure of the battery when charging and discharging
Distance Measurement between Electrodes are repeated.
This system enables CT scanning while charging and discharg-
Fig. 7 and Table 1 show the results of distance measurement between ing the lithium-ion battery inside the device* (Fig. 9). It can be
3
electrodes. In addition to measuring lengths on the cross-sectional connected to a charge/discharge device prepared by the customer.
image, the pitch of the cathode and anode are also measured from the
line profile of the gray value as shown in Fig. 8. *3 The main specifications of the X-ray CT are the same as those of the standard
inspeXio SMX-225CT FPD HR Plus.
[4] Minimum di erence in height
between dissimilar electrodes [2] Anode meandering width
Charge/discharge device

[6] Distance between anodes
[1] Cathode meandering width
[3] Maximum di erence in height A
between dissimilar electrodes
B
[5] Distance between cathodes
Fig. 9 inspeXio™ SMX™-225CT FPD HR Plus with Charge/Discharge
Fig. 7 Result of the Distance Measurement between Electrodes Attached System (Illustration)
Fig. 10 shows a cross-sectional image of a 18650 type LIB cell
Table 1 Result of the Height and Width Measurement between Electrodes before and after the charge/discharge test. In this cross-sectional

Measurement points Result (mm) image after the test, deformation of the electrodes can be seen in
the part indicated by the red frame. Even if the battery has no prob-
[1] Cathode meandering width 0.248
lem in appearance, the internal electrodes may be deformed. It is
[2] Anode meandering width 0.293
possible to observe the inside non-destructively by using the X-ray
[3] Maximum difference in height between dissimilar electrodes 1.067
CT system.
[4] Minimum difference in height between dissimilar electrodes 0.532
A B
[5] Distance between cathodes 0.356
[6] Distance between anodes 0.348

A B
Distance between
Cathodes
Anode Current 0.356 mm
Collector Foil Cathode-Active
Materials
Fig. 10 Cross-Sectional Image of a 18650 Type LIB Cell
-A before charge/discharge -B after charge/discharge

Distance between Anodes Cathode Current
0.348 mm Collector Foil
Conclusion

This article introduces analyses of a cylindrical LIB using an X-ray
Fig. 8 Result of Distance Measurement with Line Profile of Gray-Value CT system and a charge/discharge device attached system. X-ray
-A Line profile of line A -B Line profile of line B
fluoroscopy is suitable for simple observation and inspection in a
short time, but X-ray CT is effective for more detailed observation
and analyses. By using the X-ray CT system, it is possible to meas-
ure the distance between electrodes and observe the joint of current
Charge/Discharge Device Attached System collector tab. In addition, by using the custom product charge/dis-
charge device attached system, deformation of electrodes can be
It is known that the electrodes expand and contract during charging observed in-situ.
and discharging of LIBs, and the battery deteriorates due to volume In this way, the CT system can be used in situations such as
changes and chemical changes. In deterioration evaluation and setting manufacturing conditions for development prototypes and
development for longevity, there is an increasing need to observe sampling inspection of manufactured products.

Shimadzu Journal vol.10 Issue1 22