carbon additive solutions for stop-start batteries

CARBON ADDITIVE SOLUTIONS FOR START-STOP BATTERIES Presented by Paolina Atanassova, Aurelien DuPasquier, Miki Oljaca Cabot Corporation Billerica, Massachusetts, USA

BCI Convention + Power Mart Expo May 1-3rd 2016, San Antonio, Texas, USA

Outline

2

Market adoption of carbon additives in advanced lead acid batteries

Performance needs for Start-Stop application and role of carbon

New optimized formulation for Enhanced Flooded Batteries (EFB)

New developments of PBX® products

BCI CONVENTION + POWER MART EXPO, MAY 1-3RD 2016, SAN ANTONIO, TEXAS

Market Adoption of Micro-Hybrids

3 BCI CONVENTION + POWER MART EXPO, MAY 1-3RD 2016, SAN ANTONIO, TEXAS

Market Adoption of Carbon Additives More than 15 M micro-hybrid (ISS) new cars on the road in 2015,

expected to exceed 35M in 2020

New cycling applications in electricity storage also demand

improved battery solutions

Lead acid batteries are still the preferred choice for micro-hybrids

and storage due to low cost and existing broad manufacturing

infrastructure, but threat from lithium is real

Carbon additives are a critical part of the solution for improved

performance of lead acid batteries and gaining broad market

adoption

Often less than 1% additive to negative mass can bridge key

performance gaps like dynamic charge acceptance and cycle life


Carbon blacks

Activated carbons

Fibers

Nanotubes

Graphenes Graphites

Nanofibers

Carbide-derived carbons

Carbon Blacks Most Widely Used in Advanced Lead Acid Batteries

Aerogels

0.5µ

10µ 2µ

5


30-100% improvement in DCA, and 3-10 times improvement in cycle life have been demonstrated on a cell and battery level

Full spectrum of carbon’s effects not completely known yet, but some performance effects are clear: Increased NAM surface area

Depolarization of negative plate Capacitive contribution:

Supercapacitive effect for high surface area carbons Additional nucleation sites

Carbon facilitates the PbSO4 Pb reaction by providing a conductive surface area for Pb nucleation

Restriction of crystal growth: Carbon particles affect the Pb/PbSO4 crystallization

Carbon Additives Enable Significant Improvements in Dynamic Charge Acceptance (DCA) and Cycle Life


Effect of Carbon: Increasing Surface Area of Negative Electrodes

D. Pavlov et all, J. Power Sources, 191 (2009) 58 D. Pavlov et. all, 8th International Conference, LABAT 2011, Albena, Bulgaria


8

NAM Surface Area Depends on Carbon Type and Loading

Pb

Pb

0.25% PBX51

1% PBX09

1% PBX135

0.5% PBX135

Carbons vary in morphology, surface area and surface properties

Optimal loading level depends on carbon type and is also determined by the application

For high surface area carbons typically < 1% carbon loading is necessary to achieve positive impact on performance 1%

PBX09


Surface Areas of Cabot’s PBX® Carbon Blacks vs their NAM BETs

9

Without carbon additive With 0.5% carbon black

Carbon Black Additives Change the NAM Morphology

CB

Pb Pb


How Does Carbon Affect Lead Acid Battery Performance?

10

Our PBX® additives are tailored for different applications by combining structure and surface properties

Cell performance

Which carbon characteristics influence battery performance

Mechanism of influence

Charge acceptance

Carbon type, loading and surface area of carbon and negative active mass morphology

Higher NAM surface area leads to depolarization of the negative plate and higher currents can be accepted at fixed voltage

Water loss Surface area and properties of carbon and negative active mass

When the battery is overcharged hydrogen evolution occurs on the negative active mass, both from the lead surface and from carbon surface

Cold crank

Cold crank depends mostly on lignosulfonate, less on carbon, but can be affected by the interaction between them

The ratio of lignosulfonate to lead surface area determines cold crank performance

0 % carbon 0.5 m2/g

1% PBX 135, 1.3 m2/g


Different Applications Require Different Solutions

11

Carbon Type Carbon Loading Paste Formulation

Tim

e at

Flo

at

Time Cycling/ Depth of Discharge

PAM Failure

Water Loss Grid Corrosion

PSoC: NAM Sulfation

m HEV

SLI

Reliable grid

Unreliable grid

Traction/ Forklifts

E-bikes


Our PBX® Carbon Additive Products for Lead Acid Battery Applications

12

AGM Batteries Enhanced Flooded Batteries


High and Controlled Purity of PBX® Carbon Additives PBX products produced at scale, impurities part of COA

13

Focus on metals which have strong influence on hydrogen evolution


Property Test Method

Unit Value

BET Nitrogen surface area

ASTM D6556 m2/g 1300 – 1550

OAN ASTM D2414 ml/100g 140 – 200

Iron Internal method

ppm <40

Total Co, Cr, Cu, Fe, Mn, Ni

Internal method

ppm <50

General Characteristics Formula: Carbon Aspect: Carbon black pellets CAS Number: 133-86-84 Standard Packaging 8 kg bags

PBX51 Typical Values*

*The data in the table above are typical test values intended as guidance only, and are not product specifications.

14

0.25% PBX51

0.25% PBX51

PBX® Additive Properties and Typical Applications


15

PBX® 09 and PBX 51 Additives Provide DCA/Cycle Life Benefit in AGM batteries

At loadings of 0.25-0.5% in negative paste, PBX additives can deliver:

State of the art DCA

2-3x cycle life improvements

Battery applications:

High DCA Start Stop

E-bikes

Telecom

Energy Storage


Carbon Additives in EFB Automotive Start-Stop

Must improve cycle-life and dynamic charge acceptance (DCA); AND pass cold

crank and water loss testing

New benefit Test method

Dynamic charge acceptance

Current at 5-20sec Karden DCA test

Cycle-life HRPSoC (VRLA) 17.5% DOD cycling (EFB)

Conventional target Test method

Cold crank Cold start, -18°C

Water loss Water loss on overcharge, 60°C


0 200 400 600 800 1000 1200 1400 1600 1800

1.8

1.9

2.0

2.1

1% PBX55_dry mix

1% PBX55_pre wet

1% PBX135_dry mix

1% PBX135 pre-wet

0.2% VXC72_control

En

d o

f d

isch

arg

e v

olta

ge

Cycle#

PBX® 135 Additive Best Cycle Life at 17.5%, DOD Cycling at 50% SOC (without equalization) in Flooded Cells

17

PBX 135

PBX 55

control

Paste mixing recipe has strong impact of performance

Carbon and lignosulfonate loadings optimization study was conducted with PBX135 at loading of 0.5%, 0.75% and 1% and two types of lignosulfonate

Vanisperse - A

Vanisperse D-2314

control


Flooded Cells Design

NAM Paste Mix

Test Conditions

Charge Acceptance

Water Loss

PBX® Additive Performance Testing


Single 2V cells 2 negatives, 3 positives 4.4 Ah nominal capacity

Wrapped positives Compressed electrodes

1 kg, Barton PbO 0.75% PBX® 135 additive (pre-wet)

VS- A or D-2314 lignosulfonate at 0.2%, 0.4%, 0.6% loading

0.8% BaSO4

CCA Test - 18oC, I = 5x Cn A; down to 1V 17.5 DOD cycle test:

C/3 current, at 50% SOC, 17.5% DOD (40 min charge, 30 min discharge) 2.4V limit on charge voltage, cutoff at V<1.66V Without equalization step after each 85 cycles

Static CA – A, 10 min, 0oC DCA – W/g or A/Ah, 5 sec

Overcharge at 2.4V Water bath 60oC, 3 weeks

PBX® 135 Additive/LS Formulations Lead to Marked Increase of DCA

19

Increased VS-A loading beyond 0.4% eliminates the PBX 135 carbon additive benefit on DCA New VS (D-2314) formulations maintain DCA benefit even at high loadings


0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

4.00

0.2% VXC72,0.2% LS control

0.75% PBX135,0.2% LS

0.75% PBX135,0.4% LS

0.75% PBX135,0.6% LS

DC

A 5

se

c, 8

0%

SO

C [

A/A

h]

Dynamic Charge Acceptance VS-A VS-New

0

20

40

60

80

100

120

140

160

180


0.75% PBX135,0.2% LS

0.75% PBX135,0.4% LS

0.75% PBX135,0.6% LS

Co

ld c

ran

kin

g ti

me

[s]

Cold Crank -18oC VS-A VS-New

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0


0.75% PBX135,0.2% LS

0.75% PBX135,0.4% LS

0.75% PBX135,0.6% LS

3 w

ee

ks w

ate

r lo

ss [

g/A

h]

Water Loss on Overcharge

VS-A VS-New

PBX® 135 Additive/LS Formulations Lead to 2-4x Increase in Cycle

Life and Minimal Water Loss at Optimized Loading


0

500

1000

1500

2000

2500


0.75% PBX135,0.2% LS

0.75% PBX135,0.4% LS

0.75% PBX135,0.6% LS

Nu

mb

er

of

cycl

es

[#]

17.5% DOD Continuous Cycling

VS-A VS-New

New EFB Formulation Summary

Optimized formulation of 0.75% PBX® 135 carbon additive (pre-wet) with 0.3 - 0.4% D-2314 lignosulfonate delivers significant improvement in DCA/cycle-life and meets water loss/cold crank performance requirements for EFB in Start/Stop application.

Formulation can be applied starting from individual components, or as part of fully formulated expander provided by expander manufacturers.

EFB performance is driven by battery design as well:

Positive vs. negative active mass ratio and # plates

Plates compression and acid density

Lead oxide type and purity

Battery lid configuration to control evaporation during water loss test


Next Gen of PBX® Additives Aims to Eliminate Trade Offs

22

New PBX Grades

Increase DCA and cycle-life and maintain low water loss

Hydrogen evolution reaction occurs on both carbon and lead surfaces

Surface properties of carbon can be controlled to minimize hydrogen evolution and water loss

Initial validation completed


Cycling Voltammetry Test for Hydrogen Evolution Rates on Carbon Enables Selection of New Concepts

Ex-situ measurement in liquid 3 electrode cell

23

Reference electrode RE = SCE Counter electrode CE = graphite rod Working electrode WE = CB coated on graphite rod


High DCA and Low Water Loss Validated on Cell Level

24

0.00

1.00

2.00

3.00

4.00

5.00

6.00

0.5% PBX51,0.2% LS -Control 1

0.5% PBX51,0.4% LS -Control 2

0.5%PBX51modA,

0.2% LS

0.5%PBX51modB,

0.2% LS

0% carbon,control

g/A

h, A

/Ah

DCA, 80% SOC [A/Ah]3 week water loss, g/Ah

Modified PBX® 51


Effect of Rest Time on DCA

BCI CONVENTION + POWER MART EXPO, MAY 1-3RD 2016, SAN ANTONIO, TEXAS 25

0.00

0.50

1.00

1.50

2.00

2.50

0.2% VXC72Control

0.5% PBX51Control 1

0.5% PBX51Control 2

0.5% PBX51Mod A

0.5% PBX51Mod A "Dry"

DC

A @

5s,

90

% S

OC

[A

/Ah

10 min rest

24h rest

Good Balance of Performance for Modified PBX® 51 Along with Formulation Optimization

Flooded 4.6 Ah single cells

All normalized to

PBX 51, 0.4% VS-A =100

26

0.00

0.50

1.00

1.50

2.00

2.50

PBX51_modA(0.2%VSA)

PBX51_modA(0.4%VSA)

PBX51_modB(0.2%VSA)

PBX51_modB(0.3%VSA)

PBX51(0.2% VSA)

PBX51(0.4% VSA)

0% carbon(0.2% VSA)

CCA (s)

DCA

17.5% DOD Cycles


Over 130 years in operation

Founded in 1882

NYSE: CBT since 1968

Global specialty chemicals and performance materials company

44 manufacturing sites in 21 countries

Core technical competencies in fine particles and surface modification

FY2015 sales: $2.9B

About Cabot Corporation A rich and unique history


Global Leaders


carbon black #1 cesium formate #1

fumed metal oxides #2 activated carbon #2

inkjet colorants #1

Global Asset Base to Serve Customers

44 manufacturing sites in 21 countries, all with local management teams 30 sales locations in 20 countries

manufacturing sites sales locations affiliates regional headquarters


Acknowledgements

30

Cabot Corporation, USA

Institute of Electrochemistry and Energy Systems - BAS, Bulgaria

Lignotech, USA

Thank you for your attention!


The data and conclusions contained herein are based on work believed to be reliable, however, Cabot cannot and does not guarantee that similar results and/or conclusions will be obtained by others. This information is provided as a convenience and for informational purposes only. No guarantee or warranty as to this information, or any product to which it relates, is given or implied. This information may contain inaccuracies, errors or omissions and CABOT DISCLAIMS ALL WARRANTIES EXPRESS OR IMPLIED, INCLUDING MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE AS TO (i) SUCH INFORMATION, (ii) ANY PRODUCT OR (iii) INTELLECTUAL PROPERTY INFRINGEMENT. In no event is Cabot responsible for, and Cabot does not accept and hereby disclaims liability for, any damages whatsoever in connection with the use of or reliance on this information or any product to which it relates. © 2016 Cabot Corporation.

carbon additive solutions for stop-start batteries

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