Brian J. Landi - OECD
Transcript of Brian J. Landi - OECD
Nanomaterial approaches to enhance lithium ion batteries Potential Environmental Benefits of Nanotechnology:
Fostering Safe Innovation-Led GrowthJuly 17th, 2009
Brian J. LandiAssistant Professor of Chemical Engineering and Sustainability
NanoPower Research Laboratories (NPRL)Golisano Institute for Sustainability (GIS)
Rochester Institute of [email protected]
Potential Environmental Benefits of Nanotechnology: Fostering Safe Innovation-Led Growth
Rechargeable Batteries
• Rechargeable batteries, also known as storage batteries, are a continuing strong market, with worldwide sales of $36 billion in 2008. The rechargeable battery market will rise to $51 billion by 2013.
• In the US, lead-acid battery technology continues to head rechargeable battery sales with a rechargeable battery market share of 79% in 2008.
• The portable rechargeable battery market, of which lithium-ion has a 75% share, is the fastest growing segment of the rechargeable battery market, showing world market growth of 20% in 2008.
Recent Economic Trends (source: Aarkstore Enterprise)
Potential Environmental Benefits of Nanotechnology: Fostering Safe Innovation-Led Growth
Advantages of Lithium Ion
•Higher Energy and Power Density•Higher Cell Voltage (2 to 3X over Ni-X)•High charge rates available •Low Self discharge rate (1-5%/month)•Chemistry is form factor dependent (flexible design)•Life can exceed tens of thousands cycles
Portable Energy Challenge: Energy demand exceeds supply
• Increase Energy Density (carry more)• Fast Recharge (refill often)• Device Energy Efficiency (use wisely)
Advantages of Lithium Ion
→
→
Side note: ZPower has reported that Silver Zinc technology has higher energy density than Li ion
Potential Environmental Benefits of Nanotechnology: Fostering Safe Innovation-Led Growth
Energy Density vs. Power Density
• Energy (J or Wh) is the ability to do work (currency)
• Power (J/s or W) is the rate energy is consumed (spending)
• Power/Energy ratio relates to battery application
Lithium ion batteries are generallyoptimized either for high energy(e.g. for the consumer laptop orcellphone market where longerruntimes are a premium) or forhigh power (e.g. for the powertool or hybrid vehicle marketwhere brief, high power pulsesare a premium).
Potential Environmental Benefits of Nanotechnology: Fostering Safe Innovation-Led Growth
Demands for Rechargeable Batteries
Altairnano and A123 Systems have independently developed 2MW power units for demonstration of utility-grade energy storage as a replacement for lead acid batteries.
HEV: P/E = >15 PHEV: P/E = 3-10EV: P/E = <3
Source: US DOE
Consumer Electronics
Automotive
Grid and Renewable Energy Storage
Industry Considerations
-Battery size (energy density)-Number of units
-Cell form factorsfemanagement
Potential Environmental Benefits of Nanotechnology: Fostering Safe Innovation-Led Growth
Considerations for Vehicles
• Battery Size and Cost (today: $1000+/kWh)
HEV:1-2 kWh, PHEV: 5-15 kWh, EV: 40+ kWh
• Safety – battery abuse from overcharge, physical damage, or high temperature; high voltage (300-400 V) concerns
• Policy Incentives – if economics are only driver, then it directly competes with oil:
Electric vehicle with a $10,000 battery requires oil to exceed $125/barrel to equal 5 year total cost of ownership in a Volkswagen Golf 1.6 driven 15,000 km annually – source: Boston Consulting
• Model for ownership – buy electric vehicle, lease electric vehicle, or battery exchange (better place model)
• Manufacturing and battery design
Potential Environmental Benefits of Nanotechnology: Fostering Safe Innovation-Led Growth
Battery Manufacturing…for Vehicles
Today…18650 cells
The Tesla Roadster batterypack (53 KWh-375 V) iscomprised of about 680018650 cells; pack has amass of about 450kg.Source: Tesla Motors
In the near future…
Battery design for safety, performance, and end-of-life
• United States: American Recovery and Reinvestment Act of 2009 authorized $2 billion in grants for manufacturers of advanced battery systems and components• Germany: Lithium Ion Battery 2015 $650M for 1M PHEV cars by 2020• Japan: Next Generation Vehicle Battery Program• China: National High Tech R&D Program
Global Investment in Manufacturing
~3.3 Billion cells in 2008
Potential Environmental Benefits of Nanotechnology: Fostering Safe Innovation-Led Growth
Solid-Electrolyte Interface (SEI) is a surface filmthat generally establishes between anelectrode and electrolyte and serves as apassivation layer to allow diffusion of Li+ butrestricts additional solvent reduction
Mechanism and Components of Li+
Anode – (negative) – active material, binder, substrate, additives
Cathode – (positive) – active material, binder, substrate, additives
Electrolyte – Lithium salt in mixed carbonate solvents; additives for overcharge, SEI regulation
Separator - porous polyolefin
Components
Potential Environmental Benefits of Nanotechnology: Fostering Safe Innovation-Led Growth
Active Materials Comparison
Electrode Capacity: set by intrinsic materials properties and method of fabrication (i.e. coating thickness, active material loading, etc.)
Battery voltage: set by anode/cathode materials and is derived from the electrochemical potential difference
Battery Energy Density (Wh): is the product of capacity (Ah) and average voltage (V) -the discharge profile is critical
Li4Ti5O12 has a lithium ion potential of 1.5 V vs. Li/Li+
for intercalation
Potential Environmental Benefits of Nanotechnology: Fostering Safe Innovation-Led Growth
Li+ Battery Development
There are many possible combinations of active materials for the anode, cathode, and electrolyte that are used in commercial lithium ion batteries – each combination will affect performance (i.e. voltage, energy density, cyclability, etc.)
Source: US DOE
Variation in relative constituents will alter performance and energy density (by mass and volume)
Anode
Cathode
Electrolyte
• Graphite•MCMBs•Li4Ti5O12
• Silicon• Tin• Nanotubes
• LiPF6
• Carbonates• Additives
• Solid Electrolyte• Ionic Liquids•LiBOB, LiTFSI
• Metal Oxides• Iron Phosphate• Mixed Oxides
• High Voltage Phosphates•Layered Oxides
Potential Environmental Benefits of Nanotechnology: Fostering Safe Innovation-Led Growth
Challenges with Li+ Today
Aluminum
LiCoO250 mm
MCMB
Copper 50 mm
Fabrication &Processing Cell Design &Form Factor Variations in Performance
•Coating Thickness •Binder concentration •Conductive additives •Particle surface area
Reality: Manufacturing Design affects Energy Density, Power Density, Cost, Cyclability, Safety…
Outcome: Some batteries are good for certain applications, others are not…
•Cylindrical vs. Prismatic•Container materials•Safety components
Potential Environmental Benefits of Nanotechnology: Fostering Safe Innovation-Led Growth
Source: Vukusic and Sambles, 2003
1 mm
Enhancement of light collection on the cornea of a night-flying moth
Imitating Nature
Physical
• Surface area/interfacial energy from
high surface to volume ratio
• van der Waals forces
Nanomaterials can have unique quantum confinement properties that are particle size dependent
Properties of Nanomaterials
Potential Environmental Benefits of Nanotechnology: Fostering Safe Innovation-Led Growth
Advantages of Nano in Lithium Ion
• Small particle size decreases electron diffusion parameters (benefit: high rate capability; detriment: need for percolation to current collector)
• High surface area allows active material to absorb lithium ions more effectively (benefit: higher capacity; deteriment: increased SEI)
• Small particle size may accommodate crystalline expansion of lattice (benefit: improved cyclability; detriment: lattice crystallinity)
• Nanotubes and nanowires can enhance electrical percolation and mechanical properties by entanglement
Doped LiFePO4 = 165 mAh/g*
Altairnano nano-Li titanateElectrovaya SuperPolymer®
Nanomaterials offer the potential to create a unique lithium ion battery with both high energy and power density
Potential Environmental Benefits of Nanotechnology: Fostering Safe Innovation-Led Growth
Recent Nanomaterial Research
Capacity >1000 mAh/gDirected growth
Silicon and Germanium Nanowires LiMn2O4 Nanowires
Higher Rate capability over conventional materials
Potential Limitation: conventional slurry on metal current collector
Potential Environmental Benefits of Nanotechnology: Fostering Safe Innovation-Led Growth
Single Wall Multi-Wall
• High conductivity
• Nanoscale porosity
• Electrochemical and thermal stability
• High tensile strength/Young’s modulus
Carbon Nanotubes
Carbon nanotubes can be envisioned as a rolled up graphene sheet into a seamless cylinder. The role-up vector will determine the so-called ‘chirality’ of the single wall carbon nanotube, which relates to whether the structure will be metallic or semiconducting.
Single Wall
Bundle
Potential Environmental Benefits of Nanotechnology: Fostering Safe Innovation-Led Growth
Carbon Nanotubes for Li+ batteries
CNTs can be used as a conductive additive material which increases capacity, improves cyclability, enhances rate capability and mechanical toughness due to percolation network
Review Article in the June 2009 Issue
2 CNTs can be fabricated into free-standing electrodes
− Anode – lithium ion storage• Predicted LiC2 = 1116 mAh/g, • 3X improvement over
graphite maximum of LiC6
=372 mAh/g− Active material support for ultra
high capacity semiconductors and electrical percolation pathways
Overview of potential uses
1
Potential Environmental Benefits of Nanotechnology: Fostering Safe Innovation-Led Growth
Increased specific capacity Zero voltage SOCIncreased DODHigh temperature – no binderComparable C-ratesFlexible GeometriesSemiconductor Support
CNT Advantages
Free-Standing Carbon Nanotubes Electrodes
CNT free-standing electrodes offer a constant capacity as a function of thickness which can dramatically improve the usable electrode capacity in a full battery, particularly in a high power battery design.
Potential Environmental Benefits of Nanotechnology: Fostering Safe Innovation-Led Growth
5 nm
(a) (b)
100 150 200 250 300
Ram
an I
nte
nsi
ty (
a.u.)
Raman Shift (cm-1
)
1.96 eV
2.54 eV161
181
164
179
(a) (b)
100 150 200 250 300
Ram
an I
nte
nsi
ty (
a.u.)
Raman Shift (cm-1
)
1.96 eV
2.54 eV161
181
164
179
Si-SWCNTs
SWCNTs
MWCNTs
35%50%
145%
75%
Battery Capacity Improvements
CNT free-standing electrodes have the potential to more than double the state-of-the-art battery capacity with proper design and density.
Potential Environmental Benefits of Nanotechnology: Fostering Safe Innovation-Led Growth
Challenges going forward
• Ongoing technical research is necessary
• Manufacturing/Costs are not available or competitive
• Purification of materials requires technical expertise and energy intensive
• Lack of knowledge for environmental and health risks
Bulk Powder
Paper
Nanomaterial Challenges
Lithium Ion Challenges
• August 2006, Sony recalled all battery packs sold to Dell over a multi-year period
• March 2008, LG Chemical experienced a factory fire
• Concern for battery safety (e.g. electrolyte flammability)
• Environmental effects of constituent materials
Potential Environmental Benefits of Nanotechnology: Fostering Safe Innovation-Led Growth
Dr. Ryne P. Raffaelle
Dr. Cory D. Cress
Matt Ganter
Roberta DiLeo
Chris Schauerman
Jack Alvarenga
U.S. Government
Acknowledgements