In Situ Characterization of Fatigue Behavior of Electrodes [PDF]

In-situ characterization of fatigue behavior of electrodes. Claus Daniel. Oak Ridge National Laboratory. June 10, 2010.

3 downloads 4 Views 1MB Size

Recommend Stories


Fatigue Crack Propagation Behavior of Type 316
Be grateful for whoever comes, because each has been sent as a guide from beyond. Rumi

fatigue behavior of steel friction connections
Almost everything will work again if you unplug it for a few minutes, including you. Anne Lamott

Fatigue Behavior of Cement-Treated Materials
In the end only three things matter: how much you loved, how gently you lived, and how gracefully you

experimental characterization of clay soils behavior stabilized
Happiness doesn't result from what we get, but from what we give. Ben Carson

Electro-chemo-mechanical behavior of lithium-ion battery electrodes
The greatest of richness is the richness of the soul. Prophet Muhammad (Peace be upon him)

Analysis and characterization of IPTV user behavior
Just as there is no loss of basic energy in the universe, so no thought or action is without its effects,

Study of Mobilities 'in situ'
What we think, what we become. Buddha

Characterization of different DLC and DLN electrodes for biosensor design
Those who bring sunshine to the lives of others cannot keep it from themselves. J. M. Barrie

Preparation and voltammetric characterization of electrodes coated with Langmuir-Schaefer
I want to sing like the birds sing, not worrying about who hears or what they think. Rumi

[PDF]Mechanical Behavior of Materials
Never wish them pain. That's not who you are. If they caused you pain, they must have pain inside. Wish

Idea Transcript


Project ID #ES039

In-situ characterization of fatigue behavior of electrodes

Claus Daniel Oak Ridge National Laboratory June 10, 2010 This presentation does not contain any proprietary, confidential, or otherwise restricted information

Overview Timeline

Barriers

• Start: Aug. 2009

• Poor cycle life

• End: Sept. 2012

Goals

• 25% Complete

• Cycle life: 5000 cycles • Calendar life: 15 years

Budget • Total Project Funding: $900K • Funding for FY09: $300K • Funding for FY10: $300K 2

Managed by UT-Battelle for the U.S. Department of Energy

Claus Daniel, ORNL DOE – Annual Merit Review 2010

Objectives In-situ characterization of fatigue behavior of electrodes • Development of in-situ tool to characterize mechanical degradation (crack initiation, crack growth, particle fracturing, particle loosening) during cycling. • Fundamental understanding of accumulation of defects and resulting mechanical degradation. – Opportunity to develop a real life time prediction for different materials. – True quantification of mechanical degradation

• Importance of mechanical degradation to capacity fade. 3

Managed by UT-Battelle for the U.S. Department of Energy

Claus Daniel, ORNL DOE – Annual Merit Review 2010

Milestones FY2010/11

4

Month/Year

Milestone or Go/No-Go Decision

Oct 09

Acoustic emission detection and classification of events in coin cell samples based on signal signature.

Apr 10

In-situ studies combining acoustic emission spectroscopy and X-ray diffraction

Sept 10

Establishing combination with other methods such as neutron diffraction, Raman spectroscopy, etc.

Sept 11

Understanding of physical evidence to acoustic emissions and degradation mechanisms in electrodes.

Sept 12

Development of life time prediction tools and ‘fatigue’ like models for materials behavior.

Managed by UT-Battelle for the U.S. Department of Energy

Claus Daniel, ORNL DOE – Annual Merit Review 2010

Approach • Utilizing acoustic emissions stemming from mechanical events to probe degradation • Cells are cycled while acoustic emissions are recorded and analyzed • Acoustic emissions are classified according to a set of 28 parameters in standard data analysis procedures • Additional characterization techniques such as XRD, neutron diffraction, optical microscopy, Raman spectroscopy are applied simultaneously in order to validate understanding Transient Elastic Wave Waveform Signal to AE System

Composite Electrode AE Sensor 5

Managed by UT-Battelle for the U.S. Department of Energy

Claus Daniel, ORNL DOE – Annual Merit Review 2010

Subject specific optimized sample configuration and testing with standard recipes • Composite Electrodes





Testing procedure



Silicon or carbon



PVDF, Super S Carbon (8:1:1 by wt)

• Cyclic voltammetry (CV)



NMP solvent



Cu current collector

• Constant current-constant voltage (CCCV)





Cell Assembly •

Weigh & assemble in glove box



Components

Cycling

Acoustic Emission • 22dB Threshold • Filter < 3 counts • Complimentary sensor for background AE

• Li foil • Composite electrode



• 2325 Celgard

Microscopy, diffraction, spectroscopy

• 1.2M LiPF6 in EC:DMC (3:7 by wt) •

6

2032 coin cell hardware

Managed by UT-Battelle for the U.S. Department of Energy

Claus Daniel, ORNL DOE – Annual Merit Review 2010

Acoustic emissions are analyzed in real and reciprocal space

Real time data (actuation voltage vs. time)

Reciprocal space (frequency data)

7

Managed by UT-Battelle for the U.S. Department of Energy

Claus Daniel, ORNL DOE – Annual Merit Review 2010

Technical accomplishments

8

Managed by UT-Battelle for the U.S. Department of Energy

Claus Daniel, ORNL DOE – Annual Merit Review 2010

Acoustic emissions are recorded while electrochemical cycling of samples AE from Cycling silicon – CCCV – 50mV-1.3V @ C/20

70

Amplitude [dB]

50

15000

40

10000

0.6

0

0

0.2

30

5000

0.4

Managed by UT-Battelle for the U.S. Department of Energy

Claus Daniel, ORNL DOE – Annual Merit Review 2010

Voltage [V]

0.8

Cumulative hits

1.0

60

1.2

20000

1.4

9

Data is prepared in training sets to train software for automatic event classification, background and noise are classified and removed

10

Managed by UT-Battelle for the U.S. Department of Energy

Claus Daniel, ORNL DOE – Annual Merit Review 2010

K. Rhodes, C. Daniel, E. Lara-Curzio, N. Dudney, J. Electrochem. Soc. (submitted).

Frequency may be able to distinguish source of cracks

Type 2 Surface cracks?

First Crack Initiation

Type 1 Internal cracks? AE from Cycling silicon – CCCV – 50mV-1.3V @ C/20 11

Managed by UT-Battelle for the U.S. Department of Energy

Claus Daniel, ORNL DOE – Annual Merit Review 2010

High energy acoustic emissions are generated during lithiation Hence, mud crack theory for cracking in electrode particles may not be correct

silicon 12

Managed by UT-Battelle for the U.S. Department of Energy

Claus Daniel, ORNL DOE – Annual Merit Review 2010

Theory of probability of failure can be applied to lithiation phenomena

The work is under way for formulation of physically sound damage parameter which will account for change in material elasticity upon cycling. At this time the mechanism(s) responsible for the growth of defects and damage accumulation in silicon particles is unknown but it is the subject of investigation.

silicon S. Kalnaus, K. Rhodes, C. Daniel, Eng. Fract. Mech. (submitted)

13

Managed by UT-Battelle for the U.S. Department of Energy

Claus Daniel, ORNL DOE – Annual Merit Review 2010

Brittle intercalation compounds may not need to be nanosized to significantly reduce damage

Theory: Particle sized below 44µm should have no or little cracking

S. Kalnaus, K. Rhodes, C. Daniel, Eng. Fract. Mech. (submitted)

Experiment: Confirms that those particles show more than 2 orders of magnitude less emissions

Cumulative hits [counts/mg]

5000 4000

45 ≤ D ≤ 150 µm

3000 2000 1000

D ≤ 44 µm

0 0

10

20

30

Time [h]

40

50 silicon

14

Managed by UT-Battelle for the U.S. Department of Energy

Claus Daniel, ORNL DOE – Annual Merit Review 2010

Combined acoustic emissions and X-ray diffraction has been demonstrated XRD-1

XRD-2

XRD-3

XRD-4

XRD-5

XRD-6

Voltage [V]

Current [mA]

Amplitude [dB]

Time Cu

6

Si(220) Mylar

Si(311) Cu

Mylar

5 4 3 2 XRD-1 42

52

2θ 15

Managed by UT-Battelle for the U.S. Department of Energy

Claus Daniel, ORNL DOE – Annual Merit Review 2010

silicon

Future work • Validation of scientific indications/ hypotheses • Development of in-situ combination characterization • Full understanding of relationship between particle size and mechanical degradation • Widening of included material beyond carbon and silicon materials (anodes and cathodes) • Life time understanding, predication, and “fatigue” theory development

16

Managed by UT-Battelle for the U.S. Department of Energy

Claus Daniel, ORNL DOE – Annual Merit Review 2010

Summary • Work has been limited to carbon and silicon anode materials. Work will soon be expanded to other materials (anodes and cathodes). • Monitoring of active material degradation in cycling batteries has been demonstrated. • AES techniques using coin cells have been developed and offer excellent signal transmission and cycling reproducibility. • Combined AES and XRD has been demonstrated • Complimentary characterization methods (in-situ and ex-situ) are added in order to understand physical evidence of emission • Importance of mechanical degradation to capacity fade will be investigated • New quantitative “fatigue” theory models will be developed in order to understand degradation accumulation and failure

Scientific indications obtained – to be verified in future work • • •

17

Emission frequency may allow for distinguishing the source of cracks. Mud crack theory is not applicable to non-thin film electrodes. Most cracking occurs during lithiation. Cracks may initiate in the core of the particles. Brittle intercalation compounds may not need to be nano-sized to significantly reduce cracking.

Managed by UT-Battelle for the U.S. Department of Energy

Claus Daniel, ORNL DOE – Annual Merit Review 2010

Acknowledgements • Contributors

– Kevin Rhodes, Nancy Dudney, Edgar Lara-Curzio, Sergiy Kalnaus

• Collaborators

– Rosa Trejo, Jim Kiggans, Larry Walker

This research at Oak Ridge National Laboratory, managed by UT Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725, was sponsored by the Vehicle Technologies Program for the Office of Energy Efficiency and Renewable Energy. Parts of this research were performed at the High Temperature Materials Laboratory, a National User Facility sponsored by the same office and at the Shared Research Equipment Collaborative Research Center sponsored by the Office of Science, Basic Energy Sciences Program. 18

Managed by UT-Battelle for the U.S. Department of Energy

Claus Daniel, ORNL DOE – Annual Merit Review 2010

Smile Life

When life gives you a hundred reasons to cry, show life that you have a thousand reasons to smile

Get in touch

© Copyright 2015 - 2024 PDFFOX.COM - All rights reserved.