The document discusses Cadex Electronics' technology for battery diagnostics using electrochemical impedance spectroscopy (EIS), modeling, and artificial intelligence (AI). It describes how EIS can quickly assess a battery's state of health in under two minutes by examining multiple aging effects, unlike other techniques. The technology has been used in battery research and aging experiments. Cadex sees applications in electric vehicle battery management systems, quality control, and assessing used batteries for second life uses. The goal is to provide more accurate and reliable battery monitoring to optimize performance and costs over the battery life cycle.

1. EIS/modeling/AI based battery
Diagnostics
Mar 14, 2022
Confidential and Proprietary to Cadex Electronics Inc.
By Dr. Tina Shoa
Director of Research
Tina.shoa@cadex.com

2. COMPANY PROFILE
3
 Founded in 1980 by Isidor Buchmann
 40-year track record as a leader in battery analysis
 Strong focus on creating IP and knowledge (numerous patents)
 Professional team with a broad spectrum of battery research and manufacturing experience
 Strong network of research and manufacturing partners for scaling from feasibility to mass production
Confidential and Proprietary to Cadex Electronics Inc.

3. t
KNOWLEDGE BASE
3
BatteryUniversity.com
• The “Bible for battery knowledge”
• First published in 1997
• 4th Edition Published 2016
• Bestseller with >20,000 sold
• Used as a training manual for the FBI, FDA and
others
Batteries in a Portable World
• Over half a million web-hits per month
• Ranked ~53,000 on the internet
• Prime knowledge-based web portal
• Forum for experts and users to obtain and
exchange knowledge
t
Confidential and Proprietary to Cadex Electronics Inc.

4. ENGINEERING EXPERTISE
Battery
Design
✓ All chemistries
✓ Smart Battery Management
Systems
✓ Designed for Critical
Environments
✓Plastics and Metals
✓Control Circuits and PCBs
Charger &
Analyzer Design
✓Power Management
✓PCBs
✓Charging Algorithms
✓Protection Circuits
Electro-
Mechanical Design
PC Software
Applications
✓Data Management
✓Reporting and Analysis
✓CSA, UL, CE, PSE, FDA
✓ISO 9001, ISO 13485
Embedded
Software
✓ User Interface
✓ System
Communications
Regulatory &
Compliance
4
Confidential and Proprietary to Cadex Electronics Inc.

5. 5
OUR SEGMENTS
Retail
Electrical utilities
Logistics
Military
Aerospace
Automotive
Public safety Machinery
Radio
Research
IT Telecommunications
Healthcare
Confidential and Proprietary to Cadex Electronics Inc.

6. CADEX MANUFACTURING IN VANCOUVER
6
 40,000 square feet of Lab and
manufacturing space
 Value Stream Mapping , 5S, Kanban and
JIT logistics
 PPAP for a 4+ billion-dollar company
 Low and medium volume production
 Prototyping, Pre-series and validation
batches for mass production
Confidential and Proprietary to Cadex Electronics Inc.

7. 7
Lab-graded Battery
Software system:
Control & monitor the
battery test, and
model battery and
machine behavior in
your lab
our solutions empower professionals across the world to deliver, and do, more. Anytime, anywhere.
BatteryLab QuickSort SnapLock RigidArm
Ultra-fast and
Universal Li-Ion
battery SoH check
thanks to pre-defined
battery profiling
Plug & Play Adapter
System: Cross-device
and backwards-
compatibility with over
1,800 adapters
available
Your all-in-one!
Universal battery
adapter suitable for
most battery types
with almost unlimited
mounting orientations
Spectro
Ultra-fast, non-invasive
Capacity & CCA
reading in 15 seconds.
Ensure reliable power
for your on-board
electronics
TECHNOLOGIES & PATENTS
U.S. Patent 7,622,929 U.S. Patent 7,072,871 U.S. Patent 7,019,542 U.S. Patent 6,778,913
Confidential and Proprietary to Cadex Electronics Inc.

8. CADEX BATTERY LABS
8
 3 Labs in Vancouver & Frankfurt for small
and large batteries
 Full-service diagnostics, troubleshooting,
prototyping and validation testing
 Battery cycle and stress testing
 Automated mechanical insertion testing
 Environmental and Altitude chambers
 Electrical, EMI, Altitude and other tests
Confidential and Proprietary to Cadex Electronics Inc.

9. VISION AND VALUE PROPOSITION
Our vision:
Cadex offers technology for advanced battery monitoring system allowing quick
and more reliable assessment of the battery condition to optimize battery use in
all phases of battery life cycle management, increase up-time, and decrease
operating costs.
Value proposition:
Knowing its health turn the battery to a reliable travel companion.

10. Why assessing SoH of a battery?
• More accurate mileage prediction
• Allows more frequent fast charging
• Allows early detection of failure

11. Why assessing SoH of a battery?
• Trend Analysis
• Tracking batteries over usage
• Analysing the impact of various conditions
on Battery aging
• Vehicle model and driving behaviour
• Temperature
• Predicting battery degradations in real-life
vehicle use
https://electrek.co/2018/04/14/tesla-battery-degradation-data/
Confidential and Proprietary to Cadex Electronics Inc.

12. Why assessing SoH of a battery?
• Assessing used EV batteries for second
life application
• Repurposing the battery
• Prevent early recycling
First Life
Second Life

13. Challenges of assessing battery health
 Standard battery capacity measurement is lengthy (>10 hrs).
 Charging the battery to the full charge state
 Discharging it all the way to empty state
 Standard battery capacity measurement is expensive.
 Requires high power equipment
 High operating costs
 Non-standard quick SoH assessment methods are not accurate enough.
 Only examine the internal resistance of the battery.
Cadex’s technology offers a solution for quickly assessing the SoH of the battery (< 1min). Our
technology examines multiple aging effects and that makes it unique compared to its competitors.

14. EIS/Modeling/AI based battery diagnostics
Confidential and Proprietary to Cadex Electronics Inc.

15. What is EIS?
Fourier Transform
Time Domain Frequency Domain
Frequencies from kHz to mHz
Apply AC current
𝐸 = 𝐸0𝑠𝑖𝑛(𝑡)
Measure voltage drop
𝐼 = 𝐼0𝑠𝑖𝑛(𝑡 + )
Use Ohms law
𝑍  =
𝑉0
𝑠𝑖𝑛(𝑡)
𝐼0
𝑠𝑖𝑛(𝑡+)
Electrochemical Impedance Spectroscopy is a technique to measure impedance of
electrochemical cells at various frequencies.

16. Examples of Nyquist plots
Constant Phase Element (CPE): imperfect capacitor
– 𝑍𝐶𝑃𝐸 =
1
𝑄 𝑗 𝑛
– Warburg impedance CPE with 45 degree phase
w

17. Equivalent Circuit elements
• Electrolyte resistance depends on:
– Ionic concentration, type of ions, temperature, geometry of active area
– Includes in nyquist pure real component:
• Ohmic resistance (i.e. solution, electrode, connections)
𝑅𝑖 = 
𝑙
𝐴
• Double Layer Capacitance (20-60 F/cm2)
• Electrode potential, temperature, ionic concentrations, types of ions, oxide
layers, electrode roughness, Impurity adsorption
www.annualreviews.org • Electrochemical Impedance Spectroscopy

18. • Charge transfer Resistance (Electrode/Electrolyte)
– Temperature, concentration of products, Potential
– Butler-Volmer equation determines current
Equivalent Circuit elements

19. Porous electrode model
Xu, et al, Journal of Power Sources Volume 233, 1 July 2013, Pages 277–284
Xu, et al

20. Equivalent Circuit elements
• Diffusion
– Create Warburg impedance
• High f is small (ions do not move very far)
• Low f is dominant
LD

21. Li ion battery testing at Cadex
21
- Battery used : Samsung INR21700-50E, 4.8Ah
- Used Vehicle model to convert EAP urban and highway dynamometer
driving to current profile of the battery.
- Simulated a field scenario as shown below.

22. Li ion battery aging experiment at Cadex
Samsung INR21700-50E, 4.8Ah
• The drive cycle profile is used to mimic aging in the field.
• Full charge/discharge capacity testing followed by EIS every month.
a)
b)

23. Drive cycle versus deep discharge
• In an attempt to speed up the aging process, deep charge/discharge cycling was also applied to another sets
of battery of the same model.
Nyquist plots of a cycle aged battery versus drive cycle
aged batteries are shown below

24. SEI layer formation in drive cycle aging
• Modeling suggests that SEI layer thickening happens in
batteries that were aged through drive cycle profile faster
in life than the ones aged through deep charge/discharge
profile.

25. Factors effecting EIS responses
• Aging effects
• Temperature effects
• State of charge effect
• Relaxation effects
• Depends on battery usage profile

26. Interpreting EIS data
- EIS technology is used in battery research laboratories to characterize performance.
- Scientists interpret the EIS profile.
Confidential and Proprietary to Cadex Electronics Inc.
Can AI be used to interpret EIS data?
sjelectronics

27. Training the machine-learning algorithm for
Autopilot self-driving system.

28. AI in battery diagnostics
Battery assessment
Field test I,V,T data AI
Field test
I,V,T data
AI
EIS data Multi-modeling
Battery assessment
Confidential and Proprietary to Cadex Electronics Inc.

29. EIS/Modeling/AI based battery diagnostics
Confidential and Proprietary to Cadex Electronics Inc.

30. 0
V:I
t
How does Spectro work?
 R1, C1 , R2, C2 and R3 values change as the battery ages.
 Spectro has a built-in library of multi-models.
R
charge transfer
diffusion
Our technology examines several symptoms of aging related to battery’s internal electrochemical
characteristics, by scanning the battery at different frequency using EIS, whereas other techniques only look at
one parameter relating to internal resistance.
Technology: EIS (Electrochemical Impedance Spectroscopy), modeling and Analytics
Confidential and Proprietary to Cadex Electronics Inc.
-z”
Z’
Poor
Good

31. Machine learning on EIS data
Fit to Equivalent
Circuit
•Thevenin
•Transmission
•Randel
•…
Build Prediction
Model
•Regression
•Classification
Estimate Output
•SoH
•SoC

32. Training the algorithm in the field
Tuned Models
Reinforcement &
Genetic Algorithm
Parameter search
Test < 2 min

33. EV application
Quality control in Cell manufacturing
https://insideevs.com/news/367441/ul-worlds-first-certification-repurposed-ev-batteries/
- Repurposing EV used batteries
- Real time monitoring
BMS
- Mileage prediction
- Failure analysis
- Fleet management
- Asses used EV batteries for second life

34. Quality control in Battery manufacturing
Cadex’s technology offers a low cost solution for quickly assess the quality of the cell (<2 min) .

35. Cadex’s technology offers a solution for regular updating the battery modeling and potentially accurate
assessment of SoC and hence the remaining mileage.
BMS: Accurate mileage prediction requires the knowledge of SoH
Our technology
model parameters Kalman Filter based Estimation
Remaining mileage

36. BMS: Early detection of cell failures is possible by regular EIS scanning of
the cells
Our technology
model parameters
Potential for regular mentoring of the battery in the field as it ages for early detection of failure modes.
Observer/ estimator
For Fault detections
X. Kong et al., “Pseudo-two-dimensional model and
impedance diagnosis of micro internal short circuit in lithium-
ion cells,” J. Energy Storage, vol. 27, no. November 2019, p.
101085, 2020.
Cell with dendrite

37. Assessing used batteries for second life
Cadex’s technology offers a low cost solution for quickly assess the SoH of used modules (<2 min) .

38. Potential in Stationary Battery
The Connected Modular Tester
Compact module controlled by an external tablet or phone.
Tests are initiated by a Diagnostic System tablet (or phone) and results relayed to Cadex cloud.
Confidential and Proprietary to Cadex Electronics Inc.

39. Spectro’s current Market
Confidential and Proprietary to Cadex Electronics Inc.
• We are among the top finalists of EV battery challenge sponsored by LGES
• Under evaluation by LGES for EV battery application at the moment.
• ~6000 units from first generation were sold to OEMS for starter battery service and
maintenance. We plan to deploy in EV battery market by 2023.
• Validation for EV in collaboration with LGES

40. Summary of EIS/Modeling/AI battery diagnostics
– A critical review on “Towards a smarter battery management system” : EIS based measurement as the most
effective method and identified its challenge to be the availability of an apparatus [1].
– We have overcome this barrier and has made EIS technique available for industrial application.
[1] Journal of power source 405 (2018), 18-29.
[2] Nat Commun 11, 1706 (2020).
A very recent article on “Identifying degradation patterns of lithium ion batteries from impedance spectroscopy
using machine learning” also demonstrates the value of EIS and AI in battery management systems [2].
Low cost
Research grade EIS

41. Thank You!