Hioki RM2610, Instruction Manual

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How is interface resistance calculated?
8.2 How is interface resistance calculated?
By combining multipoint potential measurement (resistance measurement) and inverse analysis
calculations, it is possible to isolate and calculate the composite layer volume resistivity and
interface resistance for lithium-ion battery electrode sheets.
In this way, it is possible to calculate interface resistance by means of a simple series of operations:
configuring several settings, placing probes in contact with the surface of the electrode sheet, and
stating measurement.
When you click
[Start]
, the system performs the following steps automatically:
1
The electrode sheet is treated as a virtual electrode sheet consisting of two layers and
one interface layer, and the resistance of each layer is labeled R1 , R2 , and r (modeling).
2
A constant current is applied to the surface of the electrode sheet, and the potential
distribution occurring on the surface is measured at multiple points (to acquire the
observed potential).
3
A calculated potential that agrees with the observed potential is calculated repeatedly
(using curvilinear regression) while treating R1 and r as the variables.
4
The R1 and r values for which the observed potential and calculated potential agree are
output as the composite layer volume resistivity and interface resistance.
Electrode sheet: Observed potential
Virtual electrode sheet:
Calculated potential
Enlarged view of
measurement probes
Composite
layer
Interface
Collector
R1
r
R2
Constant current
source
(It doesn’t matter whether the electrode sheet that is
measured is coated on one side or both sides. The
composite layer resistivity and interface resistance on the
probed surface are output.)
( R1 and R2 thickness [μm], and R2 volume
resistivity are entered by the user.)
Probes
8
FA
Q