Y. Maletin , N. Stryzhakova , S. Zelinskiy , S. Chernukhin , D . Tretyakov , S. Tychina

1. How Electrochemical Science Can Improve the EDLC Performance Y. Maletin, N. Stryzhakova, S. Zelinskiy, S. Chernukhin, D. Tretyakov, S. Tychina AABC Europe 2013, Strasbourg, June 24-28

2. How Electrochemical Science Can Improve the EDLC Performance Yunasko key targets CV and galvanostatic measurements Impedance measurements (EIS) In-pore diffusion measurements Recent test results: unit cells and modules Company development Presentation outline

3. How Electrochemical Science Can Improve the EDLC Performance Why SC’s sometimes look like the Cinderella of energy storage market? Billions were invested in Li-ion batteries over the last few decades resulting in a huge advance of this technology. SC technology was developing rather slowly and was deemed to be rather complicated and expensive for many applications. Hence, Yunasko approach: SC’s must demonstrate by far the best performance in areas where they can compete with batteries or complement them. Low cost and commercially available components should preferably be used.

4. How Electrochemical Science Can Improve the EDLC Performance Cell design for 3-electrode measurements

5. How Electrochemical Science Can Improve the EDLC Performance CV: scanning the electrode potential to (+) NOTE: potential range with Faraday processes cannot be used for long • 0V corresponds to the equilibrium potential • scan rate: 10 mV/s

6. How Electrochemical Science Can Improve the EDLC Performance CV curves: A - 3-electrode cell B - SC prototype A B

7. How Electrochemical Science Can Improve the EDLC Performance Charge accumulated in (-) or (+) potential range 2.4 3.1 7

8. How Electrochemical Science Can Improve the EDLC Performance Hybrid cell:CC charge-discharge curves

9. How Electrochemical Science Can Improve the EDLC Performance DC=2.7V AC= 5mV Freq --> 0.1Hz to 10 kHz 3 Impedance spectroscopy (Nyquist plots) SC design: 2 1- poor 2- typical 1 3 2 3- optimized 1 9

10. How Electrochemical Science Can Improve the EDLC Performance Impedance spectroscopy (capacitance and resistance vs. frequency)

11. How Electrochemical Science Can Improve the EDLC Performance Yunasko approach to reduce R and RC SC resistivity (in W.cm2) total ~ 0.8 rAl-C≤ 0.01 (in Yunasko technology) rC ~ 0.05 Thus: rEl ~ 0.75 Though: rEl-in-bulk ~ 0.15 (electrode+separator thickness) “pore resistance” ~ 0.6 11

12. How Electrochemical Science Can Improve the EDLC Performance TEM image of carbon powder Slit-shaped pores or just shear cracks of graphene layers

13. How Electrochemical Science Can Improve the EDLC Performance Why the in-pore electrolyte mobility is slow? • Pore width is mostly within 1 ÷ 3 nm (is comparable with the Debye length). • There is no potential gradient in narrow pores, and therefore, diffusion is the only driving force for ions to move. (Y.Maletin et al., 7th EDLC Seminar, FL, Dec.1997) • Diffusion can be slow due to strong interaction between the charged electrolyte species and conductive pore walls.

14. How Electrochemical Science Can Improve the EDLC Performance Correlation of in-pore diffusion coefficients with EDLC resistance NOTE: in bulk solution Deff = 10.1×10-10 m2/s Diffusion coefficients of Fc+ cationsin various NP carbons (Rotating Disc Electrode measurements, see: A.J.Bard, L.R.Faulkner; Electrochemical Methods. Fundamentals and Applications (2nd ed.); Wiley, 2001, p.335 )

15. How Electrochemical Science Can Improve the EDLC Performance Test results a) Also tested in ITS, UC Davis, CA; b)Also tested in JME, Cleveland, OH; c)Also tested in Wayne State University, Detroit, MI; d) Equipped with a proprietary voltage balancing system (patent pending).

16. How Electrochemical Science Can Improve the EDLC Performance Recent Yunasko EDLC modules 15 V, 200 F: max working voltage 16.2 V max surge voltage 18.0 V dc pulse resistance 0.5 mΩ mass 2.5 kg equipped with a proprietary voltage balancing system and temperature sensor

17. How Electrochemical Science Can Improve the EDLC Performance basic city duty cycle Yunasko competitive advantage: low heat generation V ΔT: cells in the centre A, charge cells at the edge A, discharge Time, s Continuous cycling the module over 8 hours

18. How Electrochemical Science Can Improve the EDLC Performance Ragone plot: EDLC vs hybrid devices As tested in ITS, UC Davis, CA

19. How Electrochemical Science Can Improve the EDLC Performance Hybrid cell: cycle life(charge/discharge between 2.7 and 1.35 V)

20. How Electrochemical Science Can Improve the EDLC Performance Hybrid cell: temperature/rate performance

21. How Electrochemical Science Can Improve the EDLC Performance Company background and prospects Principal researchers participate in various supercapacitor projects since 1989 YUNASKO Ltd: registered in the UK since 2010 Subsidiaries: YUNASKO-Ukraine: R&D, design bureau and pilot plant since 2010 YUNASKO-Latvia: industrial scale production will start in 2014

22. How Electrochemical Science Can Improve the EDLC Performance R&D team: breakthrough story 22

23. How Electrochemical Science Can Improve the EDLC Performance Electrochemical methods are a powerful instrument to show a way to SC improvements. Yunaskotechnology* enables to significantly reduce SC resistance and to achieve the power density up to 100 kW/kg. Yunasko hybrid devices* demonstrate by far larger energy and power density than competing hybrids. First industrial scale production will soon be launched. Yunasko is open to cooperation with investors and industrial partners. * US and EU patents pending Conclusions

24. How Electrochemical Science Can Improve the EDLC Performance Acknowledgements Many thanks to Dr. Andrew Burke (ITS) and Prof. John R. Miller (JME) for stimulating discussions and valuable help in testing Special thanks to Dekarta Capital Fund for investing in the Yunaskoproject Participation in EU FP7 Energy Caps project is very much acknowledged

25. THANKS FOR YOUR ATTENTION! Please visit us at: www.yunasko.com E-mail: ymaletin@yunasko.com