The Materials Science of Lithium-Ion Batteries (Sept 2014)

Lithium Ion BatteriesMaterials Science of Energy Technologies
Andrew Gelston
September 19, 2014

Agenda
•Lithium Ion
–Electrons on Demand
–Battery Overview
–Materials Overview
•The 18650 Cell
–What’s a 18650 Cell?
–Composite Materials
–Material Issues
Degradation
Recycling
•Today’s world
–Lithium Ion -Solved Issues
Economics
Energy Density
–Impacts on Other Industries
Electric Cars
Electric Planes
Commercial -Utility Scale Energy Storage
Distributed Virtual Power Plants

During discharge, Li + ions migrate through the electrolyte and electrons flow through the external circuit, both moving from the anode (–electrode) to the cathode (+ electrode)
Any material combination that functions in this way is a “lithium –ion” battery
What exactly is a “Lithium Ion” battery(1)
Source: Technology and Applied R&D Needs for Electrical Energy Storage. March 2007. US Department of Energy Office of Science.
1) Source File

Afully functioning lithium ion battery
The components of an end user battery module(1)
Source: Lithium-ion Batteries for Hybrid and All-Electric Vehicles: the U.S. Value Chain. October 5, 2010. Center on Globalization, Governance & Competitiveness Duke University
1) Source File
Focus

Abattery discharging. How many electrons can one send from the anode to the cathode per kg and per liter, how fast can one send them is determined on a cell level
Li = Li++e-
e-
•+e-
(M)Ox+Li+ + e-=Li(M)Ox
-
A idealized Li+ Cell discharging(1)
Source: Report of the Basic Energy Sciences Workshop for Electrical Energy Storage. July 2007. John B. Goodenough, University of Texas, Austin
1) Source File

Sometimes, a picture is not worth a thousand words
This list is not exhaustive
Even the shape of the INDIVIDUAL Cathode/Anode matter
What exactly is a “Lithium Ion” battery(1)
1) Source File

Anode
LiC6
Graphite [Carbon]
Li
Lithium Metal
•Highest possible energy density
Electrolyte
•LiPF6-Current State of Art
1.Well balanced properties
2.Sensitive to moisture and high temperature
3.Difficult to prepare and purify
On a basic level
The Actual Reactionsbetween materials(1)
Source: Ibid and Lithium Ion Batteries: Going the Distance. Feb 2011. AxeonTechnologies
1) Source File
Cathode
Li Co O2
Current state of art
•Not scalable
•Cobalt is scarce
•Batteries could be better
Li (Ni1/aMn1/bCo1/cAi1/d)
Ox
•Lithium Nickel ManganeseCobaltOxide [NCM]
•NickelCobaltAluminum[NCA]
•Lithium ManganeseOxide [LMO]

The voltage difference between the anode and cathode determines the cell power, while the anode’s lithium content determines its energy density. About a million other things affect lifespan and performance
Source: Cathode materials for next generation lithium ion batteries. May 2013. JiantieXu , ShixueDou , HuakunLiu , LimingDai. Case Western.
1) Source File
Anode and Cathode Materials(1)

Xyz
ab
Source: Issues and challenges facing rechargeable lithium batteries. November 2001. J.-M. Tarascon& M. Armand [nature.com]
1)Source File
2)Ignores Silicon combination anodes
Dendrite growth is related to cycling and degradation. Dendrite growth is the cause of eventual natural lithium ion battery failure
Anode and Cathode Materials(1)(2)

Part of the equation
Cathode Materials(1)
1) Source File

Backup chart in case the questions get technical. Side note, the NCM has ~25% better energy capacity when used in low power applications. With an error range of about 20%
Battery capacity as a function of discharge current(1)
Source: Recent developments in cathode materials for lithium ion batteries. January 2009. Jeffrey W. Fergus. Wilmore Laboratories
1) The error bars (for both the x and y axis) represent the difference between chemistry sample measurements. Not enough batteries were tested to give truly accurate numbers

Almost everyone used to use graphite, but there is now experimentation into other lithium material combinations. Carbon is quite cheap, so funding has been low
I don’t understand this table fully
Source: High-Capacity Anode Materials for Lithium-Ion Batteries key: Choice of Elements and Structures for Active Particles. 2013. Naoki Nitta and Gleb Yushin. particle-journal.com
1) Source File
Anode Materials

There is still a long way to go between physical limitations on performance and current state of art technology
Battery Chemistry Energy/KG(1)
Battery 2010 Limitations(2)
1)Source: Battery University –2010 (does not include NCA)
2)Source: IBID -Issues and challenges facing rechargeable lithium batteries
Cobalt Cathodes might be the best,
but its too expensive

Things that are cheap can be actually made into other things and sold
I understand this table
Source: High-Capacity Anode Materials for Lithium-Ion Batteries key: Choice of Elements and Structures for Active Particles. 2013. Naoki Nitta and Gleb Yushin. particle-journal.com
1) Source File
Cheap Materials Matter

Major changes to the electrolyte, anode, separator and cathode are all expected. Some of these have occurred by now (2014)
Next Generation Materials(1)
1) This was made almost half a decade ago.

Li batteries come in all shapes and sizes. This makes any testing of different cathodes, even between the same chemistry of anode, suspect unless the cell’s all use the same form factor
Battery Cell Form Factors(1)
1) Source File

The 18650 form factor [A] is the most widely used and versatile for commercial energy storage today. It will provide our point of reference
The 18650 Assembly Process and Product(1)
Source: Cost comparison of producing high-performance Li-ion batteries in the U.S. and in China. November 2012. Ralph J. Brodd, Carlos Helo. Journal of Power Sciences
1) Unless otherwise noted, assume that all cells discussed in the following sections are now are 18650 form factor with carbon anodes and LiPF6electrolytes. The cathodes different often, read notes

The materials of lithium ion batteries can differ significantly. Lithium is not a major component.
18650 Cathode Material Chemistries(1)
Source: Economic and environmental characterization of an evolving Li-ion battery waste stream. February 2014. XueWang , Gabrielle Gaustad, Callie W. Babbitt , Chelsea Bailey , Matthew J. Ganter, Brian J. Land. Journal of Environmental Management
1) Think of this as “first principles” battery cost breakdown

Anyone with a smartphone knows that batteries degrade over time and with use. In the industry, this phenomenon is called
Degradation is primarily caused by cell level SOC & operating temperature and secondarily by cycling [usage] with natural time decay contributing slightly
Source: Cathode refunctionalizationas a lithium ion battery recycling alternative. January 2014. Matthew J. Ganter, Brian J. Landi, Callie W. Babbitt , AnnickAnctil, Gabrielle Gaustad. GolisanoInstitute for Sustainability
1) Mostly just illustrative, this is cycling capacity fade
Capacity Fade(1)

Degradation of a Li battery is determined by how much it cycled cumulatively & to what depths [DOD], how long it is sitting peaceful at a certain state of charge [SOC] and, most importantly, the temperature
Cycling at different temperatures(1)(2)
Source: Temperature dependent ageing mechanisms in Lithium-ion batteries -A Post-Mortem study. March 2014. Thomas Waldmann, Marcel Wilka, Michael Kasper, MeikeFleischhammer, Margret Wohlfahrt-Mehrens. Elsevier BV
1)Purposeful cycle to death study (1c charge/discharge rate continuous until SOHmax= 80%).
2)Li(Ni1/3Mn1/3Co1/3)O2L & LiyMn2O4BLEND (?) cathode

Pre/Post cycling 104image. The anode (graphite) looks like it changed more then the cathode. The scientists agree
Post Cycling Anode and Cathode(1)(2)
a) New anodeb) New cathode c) aged and cycled [SOH 80% T = 70c] anode d) aged and cycled cathode
Anodes (negative) -
Cathodes (positive)+

There is evidence that the increased resistance due to material migrating from the cathode to the anode during cycling is accelerated at temperature extremes
Deposition 101(2)
1)Only 8 cells tests, which precludes drawing scientific conclusions. However, the trend does seem convincing.
2)Source: A review of lithium deposition in lithium-ion and lithium metal secondary batteries. January 2014. ZheLi , Jun Huang , BorYann Liaw, Viktor Metzler , JianboZhang. Elsevier B.V
A Correlation to explain the picture(1)

Rearranging the chemistry of the anode/cathode tends to be bad for batteries. Temperature extremes accelerates the increase in internal resistance
Arrhenius Plot(2)
1)Correlation of anode thickness d [x axis] and internal resistance [y axis] of 18650 cells new, aged at hot and aged at cold temperatures. The dashed line is veryscientifically drawn, but not calculated. Correlation = Causation
2)I know what this is saying, but not how it is saying it.
internal resistance
[% original] Another Correlation to explain the effect on internal resistance(1)

Anode-Cathode Internal Electrical Increased Resistance (1)
Source: Performance of LiNiCoOmaterials for advanced lithium-ion batteries. August 2005. Yuichi Itou, Yoshio Ukyo. Toyota Central R&D Labs
1)Li(Ni.8Co.15AL.05)O2 cathode chemistry, 60c temperature testing, 500 cycles.
Another Study. Different cathode chemistries, same everything else. NCA battery chemistry (Tesla Model S Chemistry, first gen). They basically found the solution to degradation due to temperature back then
Degradation is primarily caused by cell level SOC & operating temperature and secondarily by cycling [usage] with natural time decay contributing slightly

At first, this seemed like another good paper to just grab some temperature resistance and capacity change statistics. But, one thing in the below graphs does not fit
60 Celsius Test(2)
1)68F -18650 cell, 2c 4.1V charge 2C 3.0V discharge –500 cycles
2)140F-18650 cell, 2c 4.1V charge 2C 3.0V discharge –500 cycles
Perfect Temperature Test [20c](1)
Where’s Waldo?

The fact that these converge is cool. BUT the fact that the 20c cell is actually GAINING capacity is insane
Cycling at different temperatures(1)(2)
Source: Performance of LiNiCoOmaterials for advanced lithium-ion batteries. August 2005. Yuichi Itou, Yoshio Ukyo. Toyota Central R&D Labs
1)Li(Ni.8Co.15AL.05)O2 cathode chemistry [NCA, also known as Tesla’s chemistry], 60c temperature testing, 500 cycles
2)This has shocking implications. Which we likely do not have time for.

Post Mortem Study of EV 18650 cell chemistry. With TERRIBLE thermal management
The “proper” cycling curves(1)(2)
Source: High Energy Lithium-Ion Storage Solutions. January 2012. FrédériqueDelcorso. HeliosInc.
1)Many Cathode Chemistries
2)Cycling conditions: 30-45 C. 80% DOD [100%-20%], 1.25c charge/discharge rate, 60 week testing period

If it is possible to engineer cells that, when cycled in completely controlled environmental conditions actually GAIN capacity, then the next part on cycling has even more relevance.
The Best Cycling Study!(1)(2)
Source: Calendar and cycle life study of Li(NiMnCo)O -based 18650 lithium-ion batteries. October 2013.
Madeleine EckerNereaNieto ,Stefan Käbitz,Johannes Schmalstieg,HolgerBlanke,Alexander Warnecke,Dirk Uwe Saue. RWTH Aachen University, Germany.
1.78 total 18650 cells tested (by far the most of any study). This means the numbers are not useless
2.Li(NiMnCo)O2–NCM chemistry –Cathode. All else kept the same.
a) 400 days = 3,200 cycles. Cells cycled with 1 C at a cell temperature of 35 C [95F] and cells stored at 50% SOC at 35 C. Different cycling depths around a mean SOC of 50% are compared
a)
a)

There was also ample proof that the temperature issue cannot be overcome with improved cell chemistry. However, we as a society have already solved temperature control. It would be nice to solve, not necessary
Time and Temperature(1)(2)
Source: Calendar and cycle life study of Li(NiMnCo)O -based 18650 lithium-ion batteries. October 2013.
Madeleine EckerNereaNieto ,Stefan Käbitz,Johannes Schmalstieg,HolgerBlanke,Alexander Warnecke,Dirk Uwe Saue. RWTH Aachen University, Germany.
a) CELLS NOT CYCLED –Stored at 50% SOC new for a year (or 400 days)
a)
a)

So I was using one of these curves for my modeling this past summer. It was ‘proprietary’. This study derives it using their ample data. I’ll explain how to use it if someone explains how to derive it!
Source
3.Cells Cycled at 1c at 35c (95f) at different voltages. Number of equivalent full cycles until capacity reaches 80% of the initial value vs. cycle depth is shown
35c Wohler Curve(3)

Even after a battery has degraded to the point of death (dendrite growth for Li batteries), the atoms do not vanish.
Li battery recycling viability
Source: Economies of scale for future lithium-ion battery recycling infrastructure. November 2013. XueWang, Gabrielle Gaustad, CallieW. Babbitt, KirtiRicha. GolisanoInstitute for Sustainability
1)Error bars represent the difference between the 4 different cathode chemistries that we previous examined18650
Total Cell Mass Components(1)

Pretty straightforward. Materials require some economics
The Result
1)Obviously, there is disagreement about recycling efficiencies
2)Assumes free input costs, i.e. no cost of collection even
Metal Prices, Recycling Efficiencies and Values of Cell Components(1)
Projected Revenue from Recycling Cell Components(2)
All of these chemistries, excluding cobalt, have no chance of being economically recyclable except for on a truly massive scale. Even then, it’s questionable

Large improvements are happening on a regular basis, the scale of investment is about to rapidly increase and the cost of raw batteries more then half
Battery Energy Storage Cost Forecast(1)
$0
$100
$200
$300
$400
$500
$600
$700
$800
$900
2014
2015
2016
2017
2018
2019
2020
$ per kWh
LG Chem (Conservative)
Tesla
McKinsey
PEV Battery Production(2)
1)Battery pack cost includes all components below the DC bus bar consisting of pack materials, battery management system, circuitry and cells. It excludes containers or buildings, HVAC and inverters/ transformers
2)Source: Lux Research

475
600
291
300
125
400
4.8
1
0.6
•Tesla plans to construct up to three U.S. plants for lithium- ion cell manufacturing, battery assembly and recycling
–Construction: Q4 2014; Commissioning: 2017
–Continue battery chemistry partnership with Panasonic
–Expected locations in California, Nevada, and Texas. Nevada first
–Capacity by 2020: 35 GWh per year and 500,000 EVs per year
–Battery price by 2020: $220 per
If we do have time -Tesla unveiled details of its high volume manufacturing plant dubbed the ‘Gigafactory’ to meet predicted demand for low cost, Gen-III electric vehicles (EV) –set for launch in 2017
Tesla’s Gigafactory
Factory
State
Size (‘000 ft2)
Employees(FTE)
Capacity (GWh)
Tesla
TBD
10,000
6,500
35
Nissan
TN
LG Chem
MI
A123
MI

Large improvements are happening on a regular basis. In fact, current technology appears to already be off the charts. It’s not as fast at Moore’s law
Panasonic Li 18650 cell evolution(2)
1)Source: Company Presentations. Current as of 2010. They have achieved their battery targets as of 2014 and become very proprietary with new chemistry information
2)Source: New Materials Extend Li-Ion Performance. 2006. David Morrison, Editor, Power Electronics Technology
Recent Improvements& Changes(1)

Management of thousands of cells through pack modules is the secret ingredient of any final lithium ion battery product. Ask Boeing.
Tesla’s “open source” attitude
Electric Cars provide a good window into what Li batteries are actually used for & what goes into the end product

If we’re not out of time, let’s talk about something serious.
Electric Aircraft
Fuel Comparison(1)
Source: Electric Flight –Potential and Limitations. Unclassified in 2012. Martin Hepperle. Institute of Aerodynamics and Flow Technology
1)Not usable energy, just raw energy

It’s hard to beat jet fuel’s factor of 60 advantage of energy content per unit mass. However, it’s not THAT bad. But still pretty bad with planes
Efficiency Comparison(1)
1)Multiplication!
It’s closer to a factor of 30 for planes and a factor of ~12 for cars. (mass useable energy content equivalence).

Everyone knows little remote control electric planes exist. It’s physically possible. So, let’s cut to the chase
Source: Electric Flight –Potential and Limitations. Unclassified in 2012. Martin Hepperle. Institute of Aerodynamics and Flow Technology
1)Someone could do this if they were willing to purchase an absolutely huge battery and only go ~1,500km in range. Kickstarter?
Could it happenIf say, someone wanted it to pay for it(1)
Boeing 747
Aircraft = 17 L/D
2014 Panasonic 18650
Cells = 700-800 Wh/Kg

The Materials Science of Lithium-Ion Batteries (Sept 2014)

More Related Content

What's hot

Similar to The Materials Science of Lithium-Ion Batteries (Sept 2014)

More from Andrew Gelston

Recently uploaded

The Materials Science of Lithium-Ion Batteries (Sept 2014)