Empfohlen
Weitere ähnliche Inhalte
Was ist angesagt?
Was ist angesagt? (20)
Ähnlich wie PSU Symposium presentation
Ähnlich wie PSU Symposium presentation (20)
PSU Symposium presentation
- 1. Mixed metal Prussian blue analogues as working electrodes for rechargeable batteries and their electrochemical properties Madeline Mackey madelinelmackey@gmail.com
- 2. What are we doing? • Need for high-energy storage for rechargeable batteries
- 3. Battery
- 4. How? • Mixing metals with Prussian blue analogues (PBAs) – Analogue: “a compound with a molecular structure similar to that of another” – Hexacyanoferrate (HCF) & hexacyanocobaltate (HCC)
- 5. What is Prussian blue • A dark blue pigment • Used in medicine as an antidote for heavy metal poisoning • Work as efficient electrodes due to redox properties Van Gogh’s Starry Night -prussian blue color
- 6. Prussian blue composition • Open framework crystal structure • Properties: – Stores countercations – Ion-exchange selectivity – Ability to catalyze electrochemical reactions Prussian blue SEM image, Cao et al.
- 7. Materials and Methods • Nickel Cobalt hexacyanoferrate. NiCoHCF. • NiCoHCF @ 60 degrees Celsius. • Iron Manganese hexacyanocobaltate. FeMnHCC. • Tin hexacyanocobaltate. SnHCC.
- 8. Materials and Methods • Facile method – Mixed metals in deionized water, mixed PBA with DI water – Add mixed metals drop-wise to PBA – Constant stirring 1 hr. – Sit for 1 day • Centrifuged and washed with ethanol
- 9. Materials and Methods • Dried in oven • annealed at 150 degrees Celsius (16 hrs.) Dried NiCoHCF Annealed NiCoHCF
- 10. Materials and Methods • Paste created • Painted onto carbon tape (electrodes) • Carbon tape electrodes annealed at 150 degrees for 2 hrs.
- 11. Testing • Set up in three-electrode battery • Scanning electron microscope (SEM) • Cyclic voltammetry • Galvanic cycling
- 12. Three-electrode Battery • Working electrode – painted carbon tape • Reference electrode – glass tube with silver nitrate and small silver metal rod • Anode/Negative electrode – graphite rod • Placed in electrolyte.
- 13. Results – SEM NiCoHCF vs. PB Prussian blue SEM image, cubical NiCoHCF SEM image
- 14. SEM – NiCoHCF NiCoHCF stacked particle SEM image
- 15. Cyclic Voltammetry • Applying voltage to the battery and observing the current. • Plot of Current versus applied Voltage • Looking for multiple peaks in graph.
- 16. Cyclic Voltammetry example -4.00E-05 -2.00E-05 0.00E+00 2.00E-05 4.00E-05 -3.00E-01 -1.00E-01 1.00E-01 3.00E-01 5.00E-01 7.00E-01 9.00E-01 1.10E+00 Current(A) Voltage (V) vs Ag/AgCl CaCoHCF with Sr in Acetonitrile (d)
- 17. Cyclic Voltammetry -1.50E-03 -1.00E-03 -5.00E-04 0.00E+00 5.00E-04 1.00E-03 1.50E-03 2.00E-03 -6.00E-01 -1.00E-01 4.00E-01 9.00E-01 1.40E+00 Current(A) Voltage (V) vs Ag/AgCl CaCoHCF with Zn in Propylene Carbonate (a)
- 18. Cyclic Voltammetry – NiCoHCF NaCoHCF with Na Perchlorate in PC-EC
- 19. Galvanic Cycling • Testing charge/discharge • Voltage vs. Time • Provides quantitative and electrochemical information about battery
- 20. Galvanic Cycling – NiCoHCF NiCoHCF with Na Perchlorate in PC:EC
- 21. Discussion/Future applications • Continue testing mixed metal hexacyanoferrate and hexacyanocobaltates • Attempt to understand the framework and further understand the electrochemical properties. • Exciting new properties to explore that may create efficient batteries.
- 22. Acknowledgments • Dr. Raj Solanki, Neal Kuperman, REU program • Funded by the National Science Foundation
- 23. References • Padigi Prasanna, Gary Goncher, David Evans, and Raj Solanki. “Potassium Barium Hexacyanoferrate – A Potential Cathode Material for Rechargeable Calcium Ion Batteries.” Journal of Power Sources 273 (2015): 460-64. Web. • • Pasta, Mauro, Richard Y. Wang, Riccardo Ruffo, Ruimin Qiao, Hyun-Wook Lee, Badri Shyam, Minghua Guo, Yayu Wang, L. Andrew Wray, Wanil Yang, Michael F. Toney, and Yi Cui. “Manganese—cobalt Hexacyanoferrate Cathodes for Sodium—ion Batteries.” J. Mater. Chem. A 4.11 (2016): 4211-223. Web. • • Pawel, J. Kulesza, Marcin A. Malik, Roman Schmidt, Anna Smolinska, Krzysztof Miecznikowski, Silvia Zamponi, Andrzej Czerwinski, Mario Berrettoni, Roberto Marassi. “Electrochemical Preparation and Characterization of Electrodes Modified With Mixed Metal Hexacyanoferrates of Nickel and Palladium.” Journal of Electroanalytical Chemistry 487 (2000): 57-65. Web. • • Zhao, Feipeng, Yeyun Wang, Xianoa Xu, Yiling Liu, Rui Song, Guang Lu, and Yanguang Li. “Cobalt Hexacyanoferrate Nanoparticles as a High-Rate and Ultra-Stable Supercapacitor Electrode Material.” ACS Appl. Mater. Interfaces ACS Applied Materials & Interfaces 6.14 (2014): 11007-1012. Web. • • Cao, Minhua, Xinglong Wu, Xiaoyan He, and Changwen Hu. Prussian blue SEM image. Digital image. Shape- controlled Synthesis of Prussian Blue Analogue Co3[Co(CN)6]2 Nanocrystals. Royal Society of Chemistry, 14 Mar. 2005. Web. <http://pubs.rsc.org/en/content/articlehtml/2005/cc/b500153f>.
Hinweis der Redaktion
- Making Batteries! Solar energy – collect and store sunlight, can be used to generate power in a car. Wind – collect and stored when windy, can be used later for electronics. So we are trying to create a battery that can store energy and be applied later on. Want: High abundance, low cost, environmentally friendly
- While charging, Lithium ions flow from the cathode anode through the electrolyte. The Electrons flow from the cathode to the electrode as well but through the charger (V line) Once all of the Li ions are at the anode, its reversed and goes the other way this is a rechargeable battery. There need to be tunnels/spaces in this material that allows ions to go in and out that is why we use prussian blue. Prussian blue’s frame work is porous and allows for this to occur.
- -these analogues are similar to prussian blue’s tunnel structure that allows for ions to go in and out.
- Found in crayons, the original “blue” in blue prints, paints, etc. Medicine turned it into a pill to counteract metal poisoning
- Open framework/tunnels = allows for rapid insertion of ions Properties = are those of an efficient battery
- -We created 6 mixed metal PBAs, however two of them are currently being tested. -Four others were created, but I will primarily talk about NiCoHCF
- NiCoHCF heated first to 60 degrees Celsius Centrifuged – spun really fast
- -electrolyte for NiCoHCF was sodium perchlorate in propylene carbonate: ethylene carbonate (1:1M)
- PB – particles are cubical, allows for insertion of ions NiCoHCF – large agglomerations -- particles are jagged and some circular.
- Again, I was attempting to look at the particle structure in order to see if NiCoHCF had similar properties to Prussian blue
- -what is cyclic voltammetry? – its applying varying voltages to the battery and sweeping the voltage and observing the current. -so the graph will be a plot of current versus the voltage/voltage potential. -since we are working with multiple metals, we expect to see the metals changing oxidation states. This causes multiple peaks/steps in the graph. -some of our materials are still in testing and cannot be released, therefore I will show you analogous work to what we were doing.
- -Here you can see that Calcium was mixed with Cobalt and HCF. There were Strontium ions in acetonitrile (the electrolyte). -as voltage potential is swept, the current increases until it hits a peak (oxidation potential) meaning extraction of ions -voltage sweep is reversed, current continues to decrease until hits peak (reduction potential) meaning insertion of ions.
- -here you see the same element CaCoHCF however with zinc ions in propylene carbonate as the electrolyte. -This graph is less defined, however you can see slight peaks.
- -My sample, NiCoHCF with sodium perchlorate in propylene carbonate:ethylene carbonate (1:1M). -25 mV per second, 20 cycles. -matching peaks. Can see a possible two peaks at the bottom. Indicate ions moving in and out (rechargeable)
- Two set voltages, upper cut off and lower cut off. Info includes battery’s chemistry, capacity, number of cycles, lifetime
- Graph of NiCoHCF with Na perchlorate in PC:EC Graph of voltage vs. time (top = upper cut off voltage, bottom = lower cut off voltage) - Cycled 20 times. (not the full graph) -charging cruve = going up Charging for cathode = ions coming out -discharging curve = going down Discharging = ions coming back in Specific capacity = 125 mA hr (??? Or second???) / g
- -understand the different electrochemical properties -from the research and testing we have done, mixed metal PBAs have exciting properties to explore and may be good candidates for batteries.
- Neal for teaching a bio student chemistry and physics – not an easy task Dr. solanki for providing the tools and his knowledge and time