Improving Battery Performance Through Particle Size Analysis

© 2014 HORIBA, Ltd. All rights reserved.© 2014 HORIBA, Ltd. All rights reserved.

© 2014 HORIBA, Ltd. All rights reserved.

Improving Battery Performance through Particle Size Analysis

Particle AnalysisJeffrey Bodycomb, Ph.D.

Date: 02/26/2014


Outline

Battery history

Particles in batteries

Measurements of particle size


History

March, 1749, Benjamin Franklin uses term “battery to describe a group of linked capacitors.

2013 National Geographic Article: Supercapacitors Amp Up as an Alternative to Batteries” http://news.nationalgeographic.com/news/energy/2013/08/130821-supercapacitors/


History

March, 1800 Volta describes producing current with a stack of zinc and copper with brine soaked cloth in between.

Now we have copper/zinc potato batteries.

~200 years later Amos Latteier builds a 5000 pound potato battery (http://latteier.com/potato/)


Oxford Bell

Battery operated bell at Oxford bell starts ringing in ~1840.

2001 discussed in Annals of Improbable Research (Volume 7, Issue 3).

2014, bell still ringing, we still don’t know how these batteries were made. The key seems to be that the bell requires very little energy so the batteries last a long time.

http://www.physics.ox.ac.uk/history.asp?page=Exhibit1


Our buddy: Zinc Carbon

1896 from National Carbon Company

Positive terminal is graphite rod surrounded by Mn(IV) oxide/carbon powder. Carbon powder is to increase conductivity.


But my battery is solid!

A battery is usually solid and quite durable.

But what if we look inside a Li-ion battery?

Anode Cathode

Particles!

20 microns6 microns


XploRA

ND フィルタホイール

sample対物ﾚﾝｽﾞ

pinholegrating

Videocamera

CCD

Light source

slit

XY stage

Raman Imaging


Ram

an In

tens

ity

500 1 000 1 500 2 000Raman Shift (cm-1)

Spectra for each point

Image showing spatial distribution

of each material

x

y

~ν

Raman imaging results

Hypercube:

X, Y, shifts


-20

-15

-10

-5

0

5

10

15

20

25

30

Y (µ

m)

-30 -20 -10 0 10 20 30X (µm)

2 µm

-30

-25

-20

-15

-10

-5

0

5

10

15

20

25

30

Y (ƒ

Êm)

-20 0 20X (ƒÊm)

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

1.00

1.10

Inte

nsity

(cnt

/sec

)

2 ƒÊm2 ƒÊm2 ƒÊm

X(μm)

Y(μm

)

0.2

0.4

0.6

0.8

1.0

1.2

1.4

Inte

nsity

(cnt

/sec

)

400 600 800 1 000 1 200 1 400 1 600 1 800 2 000Raman Shift (cm -1 )

0.00

0.10

0.20

0.30

0.40

0.50

0.60

Inte

nsity

(cnt

/sec

)

400 600 800 1 000 1 200 1 400 1 600 1 800 2 000Raman Shift (cm -1 )

0.5

1.0

1.5

Inte

nsity

(cnt

/sec

)

400 600 800 1 000 1 200 1 400 1 600 1 800 2 000Raman Shift (cm -1 )

LiCoO2 with extra oxide

carbon

LiCoO2

Raman imaging of Li ion electrodes


Battery Basics

Chemistry sets potential (voltage)…But the voltage drops due to resistance (electrical and ionic).


Moving Li

Glow discharge

Look at Li level

Pulsed RF GD OES Depth Profile Analysis of the positive electrode

GD Profiler


Battery Structure

How do I get electrons and ions to move?


Microscopic View

LiCoO2

Li moves into CoO2 octahedra slabs

How fast can the LI get in there?

Li


Particle Size!

Need to consider diffusion of Li+ into CoO2

when considering charge/discharge rate (or power, not energy)!

As particles get smaller, area for diffusion increases

Also area for undesirable side reactions increases

See M. Park, et al., J. Power Sources (2010), doi:10.1016/j.jpowsour.2010.06.060


Alkaline battery

Graphite particle size

Smaller lowers resistivity at low loadings (5%)

Lowers flex strength

D90’s from 10 to 100 microns

MnO2 powder is~100’s of microns

Anode is Zn powder (D50 of 50~200 microns) in gel


Measuring graphite

Laser diffraction

Dispersed in 0.01% Tween 20

10 minutes ultrasonic

D50: 3.05 micron

D90: 5.80 micron


Measuring Zinc Powder

This sample was measured dry by laser diffraction…there is no need to disperse it in liquid.


Measuring MnO2

Yes, laser diffraction works here as well.


Size: Particle Diameter (m)0.01 0.1 1 10 100 1000

Colloidal

Suspensions and Slurries

DLS – SZ-100

Electron Microscope

Powders

Fine Coarse

Microscopy PSA300, Camsizer

Laser Diffraction – LA-300, LA-950

Acoustic Spectroscopy

Electrozone Sensing

Disc-Centrifuge

Light Obscuration

0.001

Macromolecules

Nano-Metric

Met

hods

App

sA

pps

Size

sSi

zes


Laser Diffraction

Measure the variation in scattered intensity with angle to find particle size.


LA-950 Optics


Scattered Intensity and Size

As diameter increases, intensity (per particle) increases and location of first peak shifts to smaller angle.


Li Battery Materials

Cathode Materials:•Lithium cobalt oxide LiCoO2•Lithium nickel oxide LiNiO2•Lithium manganese oxide LiMn2O4•Lithium iron phosphate LiFePO4Anode Materials•Carbon C•Lithium Li•Lithium titanate Li2TiO3

LA Series Laser Diffraction


Repeatability (measure same material)

Below are results from measuring to different lithium compounds. Each compound was measured ten times and the relative standard deviation was found.

Sample Run 1 Run 2 Run 3 Run 4 Run 5 Run 6 Run 7 Run 8 Run 9 Run 10 Average RSD

LiMn2O4 9.75 9.93 9.75 9.66 9.83 9.78 9.76 9.75 9.79 9.60 9.76 0.90%

Li2TiO3 16.7 16.6 16.7 16.6 16.7 16.6 16.8 16.8 16.8 16.9 16.7 0.51%

Samples were measured in aqueous suspension. The mixing level and circulation level were both set to 3 during measurement.


Instrument to Instrument Agreement

Two different instruments

LA #1 LA #2 diff

LiMn2O4 9.75 9.64 0.1

Li2TiO3 16.7 16.9 0.2

D50 values


Lot Median Size (μm)

No.1 11.3No.2 11.8No.3 12.2No.4 12.5No.5 11.9

No.1

No.2

No.3

No.4

No.5

Here, 5 different lots of lithium cobalt oxide (LiCoO2) were measured. Note that there is some variation between the lots.

Lithium ion material lot to lot variation


Measu

rem

ent G

oal

Sam

ple

State

Association: Electrostatic, Van der Waals, etc.

PrimaryTertiary Secondary

Agglomerate size

particle size

Ultrasound, mixing, dispersant.

disperion

Dispersion

stability Zeta Potential


Large Scale Storage

Sodium sulfur battery

Molten sodium and sulfur at 300 C.

Load leveling (store wind/solar power) for the grid

BASE – Beta alumina solid electrolyte

Alumina lid (to keep out moisture among other things

Both require alumina. And particle size is important.


Fused White AluminaIn aqueous 0.2% hexametaphosphate

To measure alumina accurately we need to use the built in ultrasonic probe to break up loose aggregates.

Fused White Alumina

Effect of ultrasound

No ultrasonic 1 minute 3 minute

5 minute10 minute


Dispersants: More than just water

line ultrasonic mode１（μm） mode ２（μm）

―― none 12.96 72.69

―― 5 0.23 7.16

―― 10 0.24 6.08

Some materials are not readily dispersed in water and should be measured in another dispersant.

Here we use NMP.


ultrasound

0 min

10 min

small ball mill media Large ball mill media72μm

6μm

12μm

0.2μm

162μm8μm

108μm8μm

Evaluating ball milling (and ultrasound)


Dynamic:particles flow past camera

1 – 3000 um

Static:particles fixed on slide,

stage moves slide

0.5 – 1000 um2000 um w/1.25 objective

Image Analysis: Two Approaches


Data Evaluation

BinarizeFind Edges

Analyze Each Particle

Output Distribution

Raw Image


Features

Use gravity, or, better, vacuum (from a compressed air supply and venturi) in order to draw particles through instrument. Vacuum

helps keep the windows clean.

36© Retsch Technology GmbH

Dynamic Image Analysis:

Moving Particles


Reproducibility

Metal powder by Camsizer XT

xc_min [µm]10 15 20 25 30 35 40 45 500

10

20

30

40

50

60

70

80

90

Q3 [%]

0

1

2

3

4

5

6

7

8

9

q3 [%/µm]

Cookson-#8-30kPa_vvv_ZOOM_xc_min_MvCookson-#8-30kPa_TP1_vvv_ZOOM_xc_miCookson-#8-30kPa_TP2_vvv_ZOOM_xc_miCookson-#13-30kPa_TP1_vvv_ZOOM_xc_mCookson-#13-30kPa_TP2_vvv_ZOOM_xc_mCookson-#13-30kPa_vvv_ZOOM_xc_min_MCookson-#27-30kPa_TP1_vvv_ZOOM_xc_mCookson-#27-30kPa_TP2_vvv_ZOOM_xc_mCookson-#27-30kPa_vvv_ZOOM_xc_min_M

Tin and Lead Solder Powder


Particle Shape

Image capture with PSA300


Concluding Comments

Battery performance depends on particle size.

Particle size can be determined by a number of techniques including laser diffraction and image analysis.

Questions?


Questions?

www.horiba.com/us/particle

Jeffrey Bodycomb, Ph.D.

[email protected]

[email protected]

866-562-4698


Thank you


Danke

Gracias

Большое спасибо

GrazieاُشْكرΣας ευχαριστούμε

감사합니다Obrigado

Tacka dig

谢谢ขอบคุณครบั

ありがとうございました

धन्यवादநன்ற

Cảm ơn

Improving Battery Performance Through Particle Size Analysis

Technology

liion battery

battery performance

term battery

battery structure

battery history particles

raman shift

particle diameter

diffusion of li