electrochemistry & virus- templated electrodes
DESCRIPTION
Electrochemistry & Virus- Templated Electrodes. F . John Burpo Biomolecular Materials Laboratory Massachusetts Institute of Technology November 30, 2010. Electrochemistry Review Lithium Rechargeable Batteries Battery Testing. Outline. 1970 : Design Choice. Imagine. Blue Pill : - PowerPoint PPT PresentationTRANSCRIPT
Biological Engineering
Electrochemistry & Virus-Templated Electrodes
F. John BurpoBiomolecular Materials Laboratory
Massachusetts Institute of Technology
November 30, 2010
Biological Engineering
Electrochemistry Review
Lithium Rechargeable Batteries
Battery Testing
Outline
Biological Engineering
1970: Design Choice
Blue Pill: Increase CPU transistor chip density x2,000,000
Red Pill: Increase rechargeable
battery capacity x4
Imagine
Biological Engineering
Electrochemistry Basics
Cu Zn
e-e-
(-)ions(+)ions –+
Cu2+(aq) +2e- → Cu(s) +0.337 V Zn(s) → Zn2+(aq) +2e- +0.763 V
Zn(s) + Cu2+(aq) → Zn2+(aq) + Cu(s) 1.100 V
I
Salt Bridge
I
Capacity = I∙time
V
Biological Engineering
Standard reduction potentialsHalf reaction Eo, V
F2 (g) + 2H+ + e- 2HF (aq) 3.053Ce4+ + e- Ce3+ (in 1M HCl) 1.280O2 (g) + 4H+ + 4e- 2H2O (l) 1.229Ag+ + e- Ag (s) 0.799
Cu2+ + 2e- Cu(s) 0.3402H+ + 2e- H2 (g) 0.000Pb2+ + 2e- Pb (s) -0.125 Fe2+ + 2e- Fe (s) -0.440Zn2+ + 2e- Zn (s) -0.763Al3+ + 3e- Al (s) -1.676
Li+ + e- Li(s) -3.04
Biological Engineering
Anode: Zn(s) Zn2+(aq) + 2e- Eo = +0.76 V
What is Eo for the Zn/Cu cell?
Eocell = Eo
cathode - Eoanode= 0.34 – (-0.76) = +1.10 V
Net: Cu2+(aq) + Zn(s) Zn2+(aq) + Cu(s)
Cathode: Cu2+(aq) + 2e- Cu(s) Eo = +0.34 V
Eocell = Eo
cathode ̶ Eoanode
Products ̶̶ ReactantsProduct gets electron
Reactant gives electron
Biological Engineering
• For a reactant-favored reaction - Electrolytic cell: Electric current chemistry
Reactants Products
DGo > 0 and so Eo < 0 (Eo is negative)
• For a product-favored reaction – Galvanic cell: Chemistry electric current
Reactants Products
DGo < 0 and so Eo > 0 (Eo is positive)
Eo and DGo DGo = - n F Eo
Biological Engineering
When not in the standard state (Nernst Equation)
DG = - nFE DGo = - nFEo DG = DG0 + 2.303 RT log Q
E = E0 - (RT/nF) ln Q aA + bB cC + dD
• At standard state temperature, Nernst equation
ba
dc
BADC
][][][][log
n 0.0592 - E E 0
Q is the reaction quotient, or the ratio of the activities of products to reactants
Biological Engineering
= Li+
= LiPF6
Charged state
LiC6 (graphite anode)
Li2O/Coo (cobalt oxide anode)
Anod
e Cathode
FePO4 cathode
CoO2 cathode
e- e-
C (graphite anode)
Co3O4 (cobalt oxide anode)LiFePO4 cathode
LiCoO2 cathode
Discharged stateDischarging
Lithium Rechargeable BatteriesHow They Work
Courtesy Dr. Mark Allen
Biological Engineering
Energy Density & Capacity
Tarascon, Nature 414, 359-367 (2001)
Biological Engineering
Energy Density & Capacity
Tarascon, Nature 414, 359-367 (2001)
Biological Engineering
Lithium plating and dendrites
Xu, K., Chemical Reviews, 2004 4303-4417Tarascon, J.M. & Armand, M., Nature, 414, (2001)
Biological Engineering
Chemistries of electrodes
• Most common electrode system is that of LiCoO2 and graphite
charge2 1 2discharge xLiCoO Li CoO xLi xe
charge2 1 2 6discharge
6 x xLiCoO C Li CoO Li C
discharge6charge
6 xxLi xe C Li C
3.8-3.9 V vs. Li
0.1 V vs. Li
3.7 V total
Biological Engineering
Battery Form Factors
Tarascon, Nature 414, 359-367 (2001)
Biological Engineering
Ubiquitous device demand for energy storage. Need for flexible, conformable, and microbatteries. Micro Power Demand: MEMS devices, medical implants, remote sensors, smart cards, and energy harvesting devices.
Demand & Capacity
Biological Engineering
Battery Design Parameters“Design Landscape”
Pressure
Li Dendritic Growth
Cycling Life
Separator permeability
Overpotential
Charge/Discharge Rates
Energy DensityPower Density
Electrode Potentials
Solid Electrolyte Interface
Electrolyte StabilityVolume Swelling
Capacity
Background Objectives Research Design Results
Biological Engineering
Where to go next?
Background Objectives Research Design Results
Biological Engineering
Specthrie, J Mol Biol. 228(3):720-4 (1992)
M. Russel, B. Blaber.
M13 Bacteriophage
Biological Engineering
M13 Bacteriophage
Flynn, Acta Materialia 51, 5867-5880 (2003)(Marvin, J. Mol. Biol. 355, 294–309 (2006)
Background Objectives Research Design Results
Biological Engineering
Evolving the Battery
Courtesy of Angela Belcher
Background Model Aims Experiments Future
Tarascon, Nature 414, 359-367 (2001)
Biological Engineering
Bio-Battery ApplicationsUAS Systems
Soldier Load
Plug-in HybridLab on a Chip
Background Objectives Research Design Results
Biological Engineering
Synthesizing Electrodes
Mix Nanowires with carbon and organic binder
Biological Engineering
Au or Ag : capable of
alloying with Li up to
AgLi9 and Au4Li15 at very
negative potential
Taillades, 2002, Sold State Ionicshttp://www.asminternational.org/
Alloy forming anodes for Lithium ion batteries
Biological Engineering
Pure Au viral nanowires
Plateaus: 0.2 and 0.1 V/discharge0.2 and 0.45V/charge
Capacity from 2nd cycle501 mAh/g [AuLi3.69]Diameter: ~40 nm, free surface
Biological Engineering
Coin Cell Assembly
Lower Assembly
Upper Assembly
Lithium (s)
Steel Spacer
Copper Foil – Current CollectorElectrode
2 x Polymer Separators
PlasticO-Ring
ElectrolyteElectrolyte
Background Design Results Future
Biological Engineering
Capacity Calculation
8 95484 sec 1 1000 11 3600sec 1 240.8
e X A hour mA moleX X Xmole Amp g
= 881 mAh/g
arg 03 4 2arg
8 8 4 3Disch e
Ch eLi Co O e Li O Co
Biological Engineering
Calculating capacity for Gold Anodedischarge
charge xAu xLi AuLi Discharge
4 15Charge4Au+15Li 15 Au Lie
Determine the active mass, not everything in the electrode is redox active
2 0.7 0.8 1.12mg X X mg active material
Example: a 2 mg electrode with 20% inactive material (super P and PTFE binder)
1 445.97 11.12 0.4991000 1 1
g mAhmg X X X mAmg g hr
In order to discharge this electrode over one hour, apply -0.499 mA
Biological Engineering
Battery Testing16 channels for testing batteries
8 coin cell
testers
Celltest program for measurement and
analysis
Biological Engineering
Au0.9Ag0.1
Discharge/charge curves from the first two cycles
Au0.5Ag0.5
Au0.67Ag0.33
2nd cycle : 499mAh/g459mAh/g
Au0.9Ag0.1
Curve shape similar with AuCapacity at 2nd cycle : 439mAh/g
Biological Engineering
The Ragone Plot
Gasoline energy density ~12 kWh/kg and nuclear fission yields ~ 25 billion Wh/kg
Biological Engineering
So What Else Can the Virus Do?
gIII, gVIgVIIIgVII, gIX
Batteries Electrochromics Solar Cells
Fuel Cells Electronics MedicineCarbon Capture
H2O Splitting
Biological Engineering
Questions ???
Biological Engineering
Cathode Materials