Analytical Methods for Characterizing Battery Materials · 2009 Dec 3 10.0 keV 0 FRR 2.3051e+005...

© 2013 Evans Analytical Group

Analytical Methods for Characterizing Battery Materials

NCCAVS, 10th Sept 2013Sanjay Patel

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© 2013 Evans Analytical Group 2

• Founded in 1978• Leader in advanced surface analysis and materials

characterization• 700 employees• Locations worldwide

Evans Analytical Group

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Analytical Techniques in Other Industries

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Commercial Analytical Lab?

Sample Commercial Analytical Lab.

(EAG)

• Fully Confidential – no IP or patent related issues

• Fast turnaround – typically 3-5 days

• Access to best available techniques and procedures

Data Supplied


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Research and Development

•Accuracy•Lowest detection Limit

•Resolution•Physical / Chemical Information

Manufacturing / Production Control

•Repeatability•Cost•Speed – turnaround time•Sampling

Analytical Considerations

Analytical consideration for R&D and manufacturing differ

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Choosing the Analytical Method

0.E+00

1.E+01

2.E+01

3.E+01

4.E+01

5.E+01

6.E+01

7.E+01

8.E+01

9.E+01

1.E+02

Sr Cl Cu V Si

Impu

rity

Leve

l (pp

m w

t%)

Element Measured

R&DMeasurement accuracy important

Manufacturing controlChecking impurity levels are below a critical value

Optimum Technique Selection - Costs

Reduced

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7

Bubble Chart for Analytical Techniques

1. Microscopy

2. Surface Analysis

3. Bulk Analysis


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Study of SEI


TEM, cycled cathode particle

• Small spot size to analyze

individual particles

• Ability to measure elemental and

molecular components

• Shallow information depth (few

nms)

• Depth profiling ability

Analysis of SEI is essential for understanding

electrochemical mechanism which results in

loss of cell performance/cycle life.

Characterization of SEI Requires:

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9

Small Area Elemental Analysis

Auger used for imaging LiNiCoMnOcathode particles ~1 micron size particles


A09ZJ63820.spe: M010 80% capacity 20C Generic Electrolyte, Cathode EAG

2009 Dec 3 10.0 keV 0 FRR 2.3051e+005 max 3.34 min

Sur1/Area1/2 (S9D9)

100 200 300 400 500 600 700 800 900 1000

-1

-0.5

0

0.5

1

1.5

2

x 105 A09ZJ63820.spe

Kinetic Energy (eV)

c/s

CP

NiCo

Mn

NiNiCo

Co

MnMn

C

P

O• Typical spot size ~ 50 nm• Li difficult due to poor sensitivity• Elemental analysis• No molecular information

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TEM / EELS


TEM

0

10000

20000

30000

40000

50000

60000

0 5 10 15 20

Distance (nm)

Inte

nsity

C

P

O

Fe

EELS Measurement

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11

SEM / EDS

Oxygen mapped by AugerSEM tool

Oxygen mapped by EDS in SEM tool


Source of Auger electron signal

EDS

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12

Bubble Chart for Analytical Techniques


EELS/EDS – elemental analysis during microscopy

Auger – elemental analysis of small areas

XPS – Chemical/molecular information

TOF-SIMSSmall area analysis Molecular informationElemental informationDepth profiling capability

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13

Depth of Analysis / Information Depth

Analysis Depth Variation with Technique


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Lithium Titanium Oxide Anode100

80

60

40

20

01007550250μm

Total Ion Image, sample CMC: 24; TC: 1.140e+006

24

20

16

12

8

4

0

TOF-SIMS Imaging Capability

1. Ion Image – can mass select

2. Images recorded as a function

of depth

3. Entire mass spectrum recorded

per pixel – allowing any mass to

be imaged or depth profile

generated at any region

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Secondary Ion ImageTotal Counts

100

80

60

40

20

01007550250μm

Total Ion Image, Sample AMC: 302; TC: 9.952e+006

280

240

200

160

120

80

40

0

100

80

60

40

20

01007550250μm

Li+ ion image, Sample AMC: 9; TC: 5.721e+005

8

6

4

2

0

Secondary Ion ImageLithium

TOF-SIMS Mass Selection

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Variation in material grade from one supplier to another or even batch to batch (from the same supplier), should be monitored to ensure identical performance of manufactured cells.

Cell Manufacturer

Material Supplier #1



Cells with Identical Performance Manufactured

Cells with Varying Performance Manufactured

Raw Material Control


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Understanding Particle Size and Distribution

17

Efficiency and consistency of the slurry mixing process is evaluated by SEM by checking particle distribution and agglomeration

LiFePO4 cathode Graphite based anode

Cathode particles

Carbon black

Anode particles

Carbon black

~300nm size

Cathode

Anode


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18

Manufacturing Control of Electrode Materials


Minor Elements (impurity analysis): ICP-MS or GDMS

-GDMS had advantage of measuring all elements in period table rather than a select number of elements as in the case for ICP-MS. -ICP-MS provide better accuracy over GDMS.

Major Elements: ICP-OES

Organic Analysis: GC/MS

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Impurity Analysis of LiFePO4

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Samples A and B: expected to be similar

Samples C, D, E and F: expected to be similar and to have higher levels of vanadium

Samples G and H: from two different overseas suppliers


Study• Eight LiFePO4 batches ready for cell manufacture• Measure impurities

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Sample LFP-H has significantly higher levels of Si, Nb and Ti compared to LFP-A and LFP-B.


Comparison of GDMS Data

21

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This chart shows higher levels of Mn and Mg in LFP-H compared to LFP-A and LFP-B.


Comparison of GDMS Data

22

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Two cells with very different characteristics – made from similar LiFePO4 (according to supplier)

Cell Cycling Data – Performance Variation


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Summary

24© 2013 Evans Analytical Group

• Careful choice of analytical technique is essential for improving product development and good manufacturing control.

• Fast “turn-around” with optimized analytical method results in significant cost savings.

• With continued advances in battery materials, the analytical method requires changes/modification based on the material and information required.

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Thank You!

25© 2013 Evans Analytical Group

Contact:

Sanjay Patel

480-239-0602

[email protected]

www.eag.com

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mailto:[email protected]

http://www.eag.com

Analytical Methods for Characterizing Battery Materials · 2009 Dec 3 10.0 keV 0 FRR 2.3051e+005...

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