Advanced Instrumentation to Study Electrode and Electrochemistry Processes at Different Scales and Frequencies Manuel Kasper & Ferry Kienberger Keysight Labs Linz, Feb 2017 correspondence: [email protected] [email protected]
Advanced Instrumentation to Study Electrode and Electrochemistry Processes at Different Scales and Frequencies
Manuel Kasper & Ferry Kienberger
Keysight Labs Linz, Feb 2017
correspondence:[email protected][email protected]
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Agenda:
Part One: Source Measure Unit (SMU) Works as Potentiostat for Lithium Ion Cells
Part Two: Electrochemical Atomic Force Microscopy (AFM) at Nanoscale
Part Three: Fast Current and Impedance Measurements for Batteries
Summary and Outlook
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Why 3 electrodes? Becausethe flowing current causes avoltage drop in the electrolyte.The reference electrode helpsto compensate for that bysensing the potential in closeproximity to the workingelectrode.
Part One: Source Measure Unit (SMU) Works as Potentiostat for Li-Ion CellsElectrochemistry & electroanalytical methods: 3-electrode voltammetry measurements
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USB PC
Keysight Quick IV measurement software
B2900 SMU Electrochemical cells typically are equipped withthree electrodes. Voltage betweenelectrodes are few Volts for most applications and currentis in the range from 1µA – 100 mA.
Electrochemical cell
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PotentiostatThe potentiostat enforces aconstant potential between thereference electrode (RE) andthe working electrode (WE)by adjusting the currentthrough the counterelectrode (CE) accordingly.
Low sense and force can becombined effectively forminga three terminal connectionsimilar to a potentistat.
Part One: Source Measure Unit (SMU) Works as Potentiostat for Li-Ion CellsElectrochemistry & electroanalytical methods: 3-electrode voltammetry measurements
Potentiostat setup
WE
CE
RE
SMU setup
SMU connection
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Part One: Source Measure Unit (SMU) Works as Potentiostat for Li-Ion Cells
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Electrochemistry & electroanalytical methods: cyclic voltammetry
Inpu
t Vol
tage
(V
)
Time (s)
Mea
sure
d C
urre
nt (A
)
Time (s)M
easu
red
Cur
rent
(A)
Voltage (V)
Schematic for CV with feedback loop Waveforms for CV Principle measures of C-V
V M = Measured Potential
A M
= Me
asur
ed C
urre
nt Epa
ipa
ipc
anodic (oxidation)positive current
cathodic (reduction)negative current Epc
WE
CE
RE
VM
AdjustableVoltage Source
AM
Feedback Waveform
E = Input waveform
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Part One: Source Measure Unit (SMU) Works as Potentiostat for Li-Ion CellsLi-ion intercalation into TiO2: cyclic voltammetry
Liquid Cell
SMUKeysight Quick IV software
Experimental setupSketch of the experiment
Electrochemical reaction
Resulting CV curves
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Agenda:
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Part One: Source Measure Unit (SMU) Works as Potentiostat for Lithium Ion Cells
Part Two: Electrochemical Atomic Force Microscopy (AFM) at Nanoscale
Part Three: Fast Current and Impedance Measurements for Batteries
Summary and Outlook
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9500 AFM
Electrochemistry Cell
15mM CuSO4 in 0.1M H2SO4
Source: DLR Germany, Comp. Electrochemistry Prof Latz
Scales: from nano-surface to battery stacksAFM EC liquid cell
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Part Two: Electrochemical Atomic Force Microscopy (AFM) at NanoscaleNano Imaging and Cyclic Voltammetry
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Metal film lithiation and de-lithiation
Electrochemistry option available in AFM and STM mode
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Part Two: Electrochemical Atomic Force Microscopy (AFM) at NanoscaleApplication to Lithium Ion Cells
ECAFM Images of lithium foil in proprietary non-aqueouselectrolyte after (a) zero and (b) forty potential scans
Taken with AFM sitting on a Glovebox
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Agenda:
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Part One: Source Measure Unit (SMU) Works as Potentiostat for Lithium Ion Cells
Part Two: Electrochemical Atomic Force Microscopy (AFM) at Nanoscale
Part Three: Fast Current and Impedance Measurements for Batteries
Summary and Outlook
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Electrochemicalexperiment
• Three or two electrode setup• Optional DC bias (SMU)• Signal excitation with external function generator• Harmonic signals, pulses or AWG• Fast current sampling with CX3300
+ sensor head up to MHz range
• Applications:• fast current / impedace measurements for batteries• medium sized and small electrodes for electrochemistry• nonlinear processes, • corrosion processes
CX3300 result
current vs. time
CX3300 key specs
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Part Three: Fast Current and Impedance Measurements for BatteriesCX3300 Current Waveform Analyzer for Capturing Fast Transient Processes
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Dielectric processes at molecular levelElectrochemical Impedance Spectroscopy (EIS) in frequency domain:• High frequency measurements allow to estimate parasitic
circuit elements and to model the equivalent circuit of a cell • Mid frequency measures the electrode reactions• Low frequency measures migration & diffusion• Built in bias function or external bias with SMU to establish
defined DC conditions or to perform charge / discharge cycles
Alligator clampKelvin connection
Impedance probe kit
Battery / cellunder test
R1 internal cell resistanceR2 charge transferC1 double layer capacitor
E4990A complex impedance Z(ω)Built in circuit models
E4990A impedance analyzer
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Part Three: Fast Current and Impedance Measurements for BatteriesImpedance Analyzer for Broad Frequency Electrode and Battery Testing
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Agenda:
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Part One: Source Measure Unit (SMU) Works as Potentiostat for Lithium Ion Cells
Part Two: Electrochemical Atomic Force Microscopy (AFM) at Nanoscale
Part Three: Fast Current and Impedance Measurements for Batteries
Summary and Outlook
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Summary and Outlook
The B2900 SMU replaces conventional potentiostats in three electrode electrochemistry measurements with 10 femto Ampere resolution (0.01 femto Ampere with Pico Ampere Meter B2980)
Electrochemical AFM allows to study electrodes at the nanoscale (nanometer lateral resolution) while cycling the potential
The CX3300 current waveform analyzer captures fast transient processes (up to 200 MHz) at very low (100 pA) and medium (10 A) currents
Calibrated Impedance analysis (mΩ − ΜΩ) allows to study material and electrode properties of batteries in a broad frequency range (20 Hz – 120 MHz) under defined bias conditions (+/- 40 V)
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Thank you
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