Welcome to Chem 179 Nanomaterials for Supercapacitors Tim/Tianyu
E-mail:
[email protected] Office Hour: By Appointment Lab: PSB 198
Panasonic EEC-HW0D506
Class Policies
Outline
Background of Renewable Energy Research Industry
Research
Supercapacitors How/where/when they work General information
Class Policy
Class Schedule Lectures
Mon, 12:30 pm – 1:40 pm, J. Baskin Engr. 169 No lectures in week #6 and #9
Labs
Subject to change. Don’t be LATE!
Th, 8:00 am – 12:00 pm, PSB 465 Th, 2:00 pm – 6:00 pm, PSB 465 No labs in week #1, #5, #9 and #10 3-4 Groups: 3 students per group (group leader: send me your group’s name and members by next Monday.)
eCommons: Grades/Slides/Papers/Announcements etc.
Course Evaluation
Lab Reports (65% total) Scientific writing style Three lab reports in total (two regular + one final) Detailed instruction will be given in specific lectures. Title + Author Info
Part 1
Background/Introduction
Summary of experimental methods and mechanism Data Analysis and Discussion (address questions)
Conclusion
Part 2
Part 3 Part 4
Course Evaluation
Presentations (20% total) Two presentations (week #5 + week #9) Propose your own idea Week #5
Week #9
END
START
Equip with necessary knowledge/technologies
Synthesize and characterize your designed electrode Final Presentation Midterm Presentation (Propose your ideal)
(Present and Analyze your data)
Course Evaluation
Presentations (20% total) Evaluation 8.5/10 9.5/10
7.5/10 9/10
8/10
0/10
Average Score 8.3/10
Course Evaluation Lab Effectiveness (5%) Active participation? Safety?
What’s wrong with this guy?
Not Effective
Take-home Final Exam (10%) Comprehensive understanding Based on recently-published papers
Aim to provide you the best learning experience in this class!
Renewable Energy
Renewable Energy Definition From naturally-replenished sources Examples:
people.uwec.edu
www.britannica.com
Utilization Solar energy Wind energy
Harvest
electricity
Tide energy Geothermal energy
Storage
Renewable Energy Industry Famous companies in Silicon Valley Job opportunities
etc.
Renewable Energy Industry
2013-2014
insideevs.com
Renewable Energy Lab Mainly focus on four devices
Photo-electrochemical Cells
www.des.upatras.gr
(Photo-electrochemical Water Splitting, Solar Cells)
H2 H2O
hν (solar light) e- + h+
semiconductor
H2O O2
Photovoltaic Power Chemical Society Reviews 2009, 38, 253-278
Renewable Energy Lab Mainly focus on four devices
Lithium-Ion Batteries Cathode (positive electrode):
Anode (negative electrode): Overall
De-intercalation
Intercalation
Renewable Energy Lab Mainly focus on four devices
Fuel Cells Split a combustion reaction on two electrodes. 1 + O ( g ) 2 e 2H (aq) H 2O(l ) Cathode (positive electrode): 2 2 Anode (negative electrode): H 2 ( g ) 2e 2H + (aq) 1 H 2 ( g ) O 2 ( g ) H 2O( aq) Overall 2
Renewable Energy Lab Mainly focus on four devices
Supercapacitors Electricity storage www.thomasnet.com
Supercapacitors
Rough Surface General Structure of Supercapacitors
Graphene Aerogel
Charge storage device – “capacitor”
10 μm ZnO Nanowires
5 μm
Capacitance
Charge storage Mechanism: Electrical Double Layer (EDL) capacitance; Pseudo-capacitance – redox reactions.
Carbon, CNT, Graphene etc.
EDL Capacitance
Metal Oxides, Conducting Polymers etc.
Pseudo-capacitance
Why “Super”? Amount of charge that can be stored – Capacitance (C) ~100-1000 F/g
>
Supercapacitors
Charge and discharge rate: ~Seconds to fully charged state
Supercapacitors
>
~ μF/g
Parallel-plate Capacitors ~hours to fully charged state www.wirelessemporium.com
Li-ion Batteries
Why “Super”? Capacitance (EDL)
0 r S C d
0 r S d
Electric constant (=8.854 pF/m) Dielectric constant Surface area (ion-accessible) Separation b/w different chages
Why “Super”? Capacitance (EDL)
0 r S C d Commercial Supercapacitors
Name
Surface Area
Carbon Cloth
5.3 m2•g-1
Graphite Powder
6 m2•g-1
Carbon Black
~100 m2•g-1
Porous Carbon Template
~200 m2•g-1
Graphene Aerogel
~500 m2•g-1
Activated Carbon
~1200 m2•g-1
Why “Super”? Capacitance (EDL)
+ e-
+ e-
0 r S C d
+ e+ e+ e+ e-
EDL Electrode
+ e-
+ eHelmholtz layer ~0.6nm-1nm
Supercapacitors vs. Li-ion Batteries
http://batteryuniversity.com/learn/article/whats_the_role_of_the_supercapacitor
Ragone Plot
Energy Density (Wh•kg) How much energy per kg material can store
Power Density (kW•kg) How fast per kg material can charge/discharge
Supercapacitors - surface
Li-ion Batteries - bulk
Applications
Power Supply in pulse/peak model
Chemistry-A European Journal 2014, 20, 13838-13852
Applications Hybrid Vehicles (combine with Li-ion batteries)
Electrochimica Acta 2000, 45, 2483-2498
greenliving4live.com
Applications Supercapacitor Vehicles Shanghai, China
The buses can also capture energy from braking, and the company says that recharging stations can be equipped with solar panels (although this is mainly to further the perception that the vehicles have a lower carbon footprint). Ye says the buses use 40 percent less electricity compared to an electric trolley bus, mainly because they’re lighter and have the regenerative braking benefits. They’re also competitive with conventional buses based on fuel savings over the vehicle’s 12-year life, based on current oil and electricity prices. Sinautec estimates that one of its buses has one-tenth the energy cost of a diesel bus and can achieve lifetime fuel savings of $200,000.
http://www.technologyreview.com/news/415773/next-stop-ultracapacitor-buses/
Applications Commercial Products
Maxwell 723-BCAP0310P270T10 (310 F) Panasonic EEC-HW0D506 (22 F)
Maxwell BCAP3000 (1500 F)
Lab Products
Nano Letters 2013, 13, 2078-2085
Advanced Materials 2014, 26, 2676-2682
Extracurricular Readings Papers are available on eCommons.
[1] Kötz, R.; Carlen, M., Principles and applications of electrochemical capacitors. Electrochimica Acta 2000, 45, (15–16), 2483-2498. [2] Kim, H.; Park, K.; Hong, J.; Kang, K., All-graphene-battery: bridging the gap between supercapacitors and lithium ion batteries. Scientific Reports 2014, 4. [3] Winter, M.; Brodd, R. J., What are batteries, fuel cells, and supercapacitors? Chem Rev 2004, 104, (10), 4245-4269
End of Lecture #1 Thank You!
