No No 11 / 25/ 25--JulJul--05 05 –– VV 05050505

PENOX - GROUPPENOX PENOX -- GROUPGROUP

TBLS+®TBLS+TBLS+®®Improved Batteries with Micronised 4-basic Lead Sulphate Additive for Positive Plates

Ian Klein, David Hardy, Dr. Werner Nitsche

Improved Batteries with Micronised Improved Batteries with Micronised 44--basic Lead Sulphate Additive for basic Lead Sulphate Additive for Positive PlatesPositive Plates

Ian Klein, David Hardy, Dr. Werner Ian Klein, David Hardy, Dr. Werner NitscheNitsche

PENOX GmbHDeutz-Mülheimer Str. 173D-51063 CologneGermany

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LocationsLocations

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GroupGroup

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TBLS+TBLS+®®

Tetrabasic lead sulphate significantly improves the performance Tetrabasic lead sulphate significantly improves the performance of a of a lead acid battery:lead acid battery:

Stable capacity C20 in discharge and recharge applicationsStable capacity C20 in discharge and recharge applicationsLimits passivation after deep discharge (Sb free effect)Limits passivation after deep discharge (Sb free effect)Avoids softening of the active material in lifetime tests (J240Avoids softening of the active material in lifetime tests (J240 hot, VW)hot, VW)

Longer lifetime of batteriesLonger lifetime of batteriesLess variation of battery performance during lifetime Less variation of battery performance during lifetime

What prevents some manufacturers of batteries from using tetrabaWhat prevents some manufacturers of batteries from using tetrabasic sic lead sulphate ?:lead sulphate ?:

Large sized crystals of > 50 µm instead of < 5 µm for tribasic Large sized crystals of > 50 µm instead of < 5 µm for tribasic lead sulphatelead sulphateA Increased formation time (up to 100% longer) withA Increased formation time (up to 100% longer) with

More than 25% higher electrical energy consumptionMore than 25% higher electrical energy consumptionProlonged formation with rest phasesProlonged formation with rest phases

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CuringCuring--process: Basics of Crystal Structureprocess: Basics of Crystal Structure

4 Basic Lead Sulphate:4 Basic Lead Sulphate:4.PbO.PbSO4.PbO.PbSO44Hard to create the ‚seeding‘ sitesHard to create the ‚seeding‘ sites

low number of ‚seeds‘low number of ‚seeds‘large crystals large crystals few large poresfew large porescuring* time 2 curing* time 2 -- 4 h at T>80°C +steam4 h at T>80°C +steamformation: formation: -- 450 450 –– 530 Ah / kg530 Ah / kg

-- rest phases during formationrest phases during formation

3 Basic Lead Sulphate:3 Basic Lead Sulphate:3.PbO.PbSO3.PbO.PbSO44.H.H22OOEasy to create the ‚seeding‘ sitesEasy to create the ‚seeding‘ sites

high number of ‚seeds‘high number of ‚seeds‘small crystals small crystals many small poresmany small porescuring* time 14 curing* time 14 –– 24 h at 55°C24 h at 55°Cformation: formation: -- 350 350 –– 400 Ah / kg400 Ah / kg

* Curing = the development of the final crystal structure* Curing = the development of the final crystal structure

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„State of the Art“: Curing and Drying„State of the Art“: Curing and Drying

Curing to small sized 3 basic lead sulphate crystalsCuring to small sized 3 basic lead sulphate crystals

Temperature < 60°C:Temperature < 60°C:Crystal growth rateCrystal growth rate

slow: slow: 12 12 –– 24 h timescale24 h timescalecrystal size: up to 3 µmcrystal size: up to 3 µm

Risk of Risk of „Dry out“„Dry out“ of platesof plates::caused by free lead content of oxidecaused by free lead content of oxide

combined with reactivity of oxidecombined with reactivity of oxidetype of mill/reactor plays a roletype of mill/reactor plays a roleoxide may need to be stored oxide may need to be stored

Loading time delays for platesLoading time delays for platesexothermic oxidation reaction can exothermic oxidation reaction can

create partial 4create partial 4--basic structuresbasic structures

No No 77 / 25/ 25--JulJul--05 05 –– VV 05050505

„State of the Art“: Curing and Drying„State of the Art“: Curing and Drying

Curing to large sized 4 basic lead sulphate crystalsCuring to large sized 4 basic lead sulphate crystals

Temperature > 80°C Temperature > 80°C (humid environment):(humid environment):Crystal growth rateCrystal growth rate

fast: 2fast: 2–– 4 h timescale4 h timescale

large 4 basic lead sulphate large 4 basic lead sulphate crystals of 50 µm and abovecrystals of 50 µm and above

Wide distribution of crystal sizesWide distribution of crystal sizes

No No 88 / 25/ 25--JulJul--05 05 –– VV 05050505

How to obtain small sized tetrabasic lead How to obtain small sized tetrabasic lead sulphate crystals by use of seeding crystals?sulphate crystals by use of seeding crystals?

Addition of Addition of drydry--milledmilled tetrabasic tetrabasic lead sulphate crystalslead sulphate crystals

Seeding crystals limited to ca. 1 µmSeeding crystals limited to ca. 1 µmwith with high energy milling high energy milling requirementsrequirements

Higher percentage of milled powder tetrabasic Higher percentage of milled powder tetrabasic lead sulphate requiredlead sulphate required to achieve desired final to achieve desired final crystal size (can be 2crystal size (can be 2--3 times % versus TBLS+ 3 times % versus TBLS+ (R)(R) ) )

Wider particle size distribution of seed crystalsWider particle size distribution of seed crystals in in powder form powder form less homogeneous crystal size less homogeneous crystal size distribution than with TBLS+distribution than with TBLS+ (R)(R)

Operator hygiene issuesOperator hygiene issues associated with handling associated with handling fine powders versus TBLS+ fine powders versus TBLS+ (R)(R) liquid form liquid form

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How to obtain small sized tetrabasic lead How to obtain small sized tetrabasic lead sulphate crystals by use of sulphate crystals by use of TBLS+TBLS+®® ??

Penox‘ new approach: Penox‘ new approach: Wet milling of tetrabasic lead sulphate with an additiveWet milling of tetrabasic lead sulphate with an additive

Particle size < 0.5 µmParticle size < 0.5 µmChemical separation of the milled particles to avoid reChemical separation of the milled particles to avoid re--agglomerationagglomerationCuring to small sized tetrabasic lead sulphate crystals in Curing to small sized tetrabasic lead sulphate crystals in existing curing chambers:existing curing chambers:

without steam (requires min. 6 h)without steam (requires min. 6 h)with steam (ca. 1with steam (ca. 1--2 hours)2 hours)

Advantages of steam curing:Advantages of steam curing:Reduced dependence on oxide qualityReduced dependence on oxide quality44--basic crystal formation on the plate is complete in c.1hbasic crystal formation on the plate is complete in c.1hPrePre--requisite for „Concure“ (continuous curing and drying)requisite for „Concure“ (continuous curing and drying)

0,1 1 10 100Grain Size [µm]

0102030405060708090

100[%]

TBLS+

Standard 4bs Sulphate

No No 1010 / 25/ 25--JulJul--05 05 –– VV 05050505

How to obtain small sized tetrabasic lead How to obtain small sized tetrabasic lead sulphate crystals by use of sulphate crystals by use of TBLS+TBLS+®® ??

Control of 4 basic lead sulphate crystal size by Control of 4 basic lead sulphate crystal size by TBLS+TBLS+®® additionaddition

No No 1111 / 25/ 25--JulJul--05 05 –– VV 05050505

How to obtain small sized tetrabasic lead How to obtain small sized tetrabasic lead sulphate crystals by use of sulphate crystals by use of TBLS+TBLS+®® ??

Control of 4 basic lead sulphate crystal size by Control of 4 basic lead sulphate crystal size by TBLS+TBLS+®® additionaddition

No No 1212 / 25/ 25--JulJul--05 05 –– VV 05050505

How to obtain small sized tetrabasic lead How to obtain small sized tetrabasic lead sulphate crystals by use of sulphate crystals by use of TBLS+TBLS+®® ??

Advantage of Advantage of TBLS+TBLS+®®Control of the final size of 4 basic lead sulphate crystal by thControl of the final size of 4 basic lead sulphate crystal by the e amount amount of TBLS+ of TBLS+ (R)(R)added to the paste mix*added to the paste mix*

VRLA batteries:VRLA batteries:2 to 3%2 to 3% TBLS+ results in 4 basic lead sulphate crystals of about TBLS+ results in 4 basic lead sulphate crystals of about

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Application of Application of TBLS+TBLS+®® to the Positive Pasteto the Positive Paste

Add Add TBLS+TBLS+®® to the to the leady leady oxideoxide at the start of paste mixingat the start of paste mixing

0.5 to 3 0.5 to 3 % % TBLS+TBLS+®® slurry slurry to the to the leady leady oxide oxide –– no change to customer recipe* no change to customer recipe*

1 h steaming of plates in stacks at > 80°C / high humidity1 h steaming of plates in stacks at > 80°C / high humidity

dependent upon local requirements dependent upon local requirements -- 2 options:2 options:-- cure for 4cure for 4--6 h then dry 6 h then dry OROR

-- immediately start drying immediately start drying (with good air circulation to allow free lead reduction)(with good air circulation to allow free lead reduction)(high free lead content in the oxide will speed up the drying (high free lead content in the oxide will speed up the drying process)process)

In batch chambers

No No 1414 / 25/ 25--JulJul--05 05 –– VV 05050505

Dosage of Dosage of TBLS+TBLS+®® -- definitionsdefinitions

TBLS+TBLS+®® is a ca. 40% is a ca. 40% micronised micronised sulphate solids in water (slurry) sulphate solids in water (slurry) –– when addition %s are mentioned then when addition %s are mentioned then it is the weight of the it is the weight of the TBLS+TBLS+®® slurry as a % of the weight of leady oxide in the positive pasteslurry as a % of the weight of leady oxide in the positive paste mix.mix.(E.g. a 1.2% addition of TBLS+ in a 1,000 kg paste containing 80(E.g. a 1.2% addition of TBLS+ in a 1,000 kg paste containing 800 kg of leady oxide 0 kg of leady oxide add 9.6 kg of add 9.6 kg of TBLS+TBLS+ as a slurry).as a slurry).

SLI SLI SLI IND6 litre 7 litre 7.5 litre 8.5 litreper 100 kg per 100 kg per 100 kg per 100 kg

Leady Oxide kg 600 980 1,000 800 TBLS+ slurry kg 6 10 10 8 Acid kg 50 95 105 95 Water kg 80 125 145 98 Fibres kg 1 1 1 1

Total PAM weight 737 1,211 1,261 1,002

Ratios:

% TBLS+/PbO wt % 1.33% 1.33% 1.33% 1.33%% TBLS+/Leady Oxide wt % 1.00% 1.00% 1.00% 1.00%% TBLS+/Tot PAM wt % 0.81% 0.81% 0.79% 0.80%% Tetra bas solids/Leady Oxide wt % 0.40% 0.40% 0.40% 0.40%% Tetra bas solids/Tot PAM wt % 0.33% 0.32% 0.32% 0.32%

The above table shows what weight of The above table shows what weight of TBLS+®TBLS+® is to be added to achieve a 1% is to be added to achieve a 1% TBLS+®TBLS+® addition (based on the addition (based on the PenoxPenox definition of weight of slurry per weight of the leady oxide) fdefinition of weight of slurry per weight of the leady oxide) for a range of typical positive paste recipes. or a range of typical positive paste recipes. A number of other weight ratios are shown for comparison.A number of other weight ratios are shown for comparison.

No No 1515 / 25/ 25--JulJul--05 05 –– VV 05050505

Dosage of Dosage of TBLS+TBLS+®® -- Influence of PAM AdditivesInfluence of PAM Additives

It is recognised that battery manufacturers may add other additiIt is recognised that battery manufacturers may add other additives to the positive paste in order to ves to the positive paste in order to enhance features of the production process (e.g. to improve the enhance features of the production process (e.g. to improve the pastepaste--grid adhesion, reduce the grid adhesion, reduce the formation time etc). Several of these additives have been show tformation time etc). Several of these additives have been show to influence the effect of TBLS+® on the o influence the effect of TBLS+® on the crystal growth process.crystal growth process.

Sodium Sodium perborateperborate –– sometimes used to promote free lead reduction and to improve sometimes used to promote free lead reduction and to improve paste/grid adhesion. In several trials the addition of 0.5% up tpaste/grid adhesion. In several trials the addition of 0.5% up to 1% sodium o 1% sodium perborate perborate has has been shown to negatively influence the TBLS+® and lead to a broabeen shown to negatively influence the TBLS+® and lead to a broader crystal size der crystal size distribution as well as some larger agglomerates. distribution as well as some larger agglomerates.

Red leadRed lead –– is a common additive in industrial batteries and used in some Sis a common additive in industrial batteries and used in some SLI batteries LI batteries in the range 5in the range 5--15% of the leady oxide in the positive paste. It gives extra cap15% of the leady oxide in the positive paste. It gives extra capacity and can acity and can help to save formation energy and process time but on the other help to save formation energy and process time but on the other hand it tends to promote hand it tends to promote shading effects during battery life time. The addition of red leshading effects during battery life time. The addition of red lead gives high density pastes ad gives high density pastes with very small pores and may cause some disadvantages for the awith very small pores and may cause some disadvantages for the acid circulation. Trials cid circulation. Trials have shown that the red lead has a generally favourable effect ihave shown that the red lead has a generally favourable effect in that the amount of n that the amount of TBLS+® required to achieve a given crystal size can be significaTBLS+® required to achieve a given crystal size can be significantly reduced. The fine ntly reduced. The fine fraction of the red lead seems to have a similar crystal shape afraction of the red lead seems to have a similar crystal shape and size to the TBLS+® and nd size to the TBLS+® and can therefore act as ‘seeding’ sites for can therefore act as ‘seeding’ sites for tetrabasic tetrabasic sulphate. sulphate.

No No 1616 / 25/ 25--JulJul--05 05 –– VV 05050505

TBLS+TBLS+®® -- Commercial AdvantagesCommercial Advantages

SavingSaving of positive active materialof positive active materialReduction of active positive material by > 4 %Reduction of active positive material by > 4 %Higher porosity and improved homogenaity lead to a significant iHigher porosity and improved homogenaity lead to a significant increase in the ncrease in the active mass utilisationactive mass utilisation reduction in the paste density / mass per plate for the reduction in the paste density / mass per plate for the same capacitysame capacity

TBLS+® offers advantages versus :offers advantages versus :

Small sized Small sized tribasic lead sulphate crystal structurestribasic lead sulphate crystal structures ::Higher capacity and cold cranking during cyclingHigher capacity and cold cranking during cyclingLess dependence on oxide quality and shorter curing/drying proceLess dependence on oxide quality and shorter curing/drying process ss

Big sized Big sized tetrabasic lead sulphate crystal structuretetrabasic lead sulphate crystal structure ::Reduction of electrical energy required for formation by ~ 25%Reduction of electrical energy required for formation by ~ 25%Reduction of formation time by > 12 h typically Reduction of formation time by > 12 h typically Less overheating during formationLess overheating during formation

No No 1717 / 25/ 25--JulJul--05 05 –– VV 05050505

TBLS+TBLS+®® -- DistributionDistribution

Significant benefits in the sourcing/supply of Significant benefits in the sourcing/supply of TBLS+TBLS+®®for international battery manufacturers:for international battery manufacturers:

Global Global supply and distribution system based on production supply and distribution system based on production sites in Europe, Mexico and Brazilsites in Europe, Mexico and Brazil

Offers Offers

“local supply” to major battery producers“local supply” to major battery producerssecurity of supply through multiple sourcessecurity of supply through multiple sourcessame quality product across the supply networksame quality product across the supply network

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TBLS+TBLS+®® -- DevelopmentsDevelopments

With the significant improvements in the positive plates due to With the significant improvements in the positive plates due to the use of the use of TBLS+®the battery performance can be limited by the negative plates.the battery performance can be limited by the negative plates.The negative plate needs to be highly porous with a strong interThe negative plate needs to be highly porous with a strong internal structure to nal structure to minimise sludging (expanders such as lignum sulphonate are addedminimise sludging (expanders such as lignum sulphonate are added to enhance the to enhance the structure).structure).During charging the negative plates reach their nominal capacityDuring charging the negative plates reach their nominal capacity before the positive before the positive plates. Whilst the positive plates are coming up to capacity theplates. Whilst the positive plates are coming up to capacity there can be heat re can be heat generation on the negative plates leading to breakdown of the exgeneration on the negative plates leading to breakdown of the expander and water pander and water disassociation.disassociation.A typical solution is to either add an additional negative plateA typical solution is to either add an additional negative plate or to increase the or to increase the active mass on the plates (buildingactive mass on the plates (building--in redundant/excess capacity). in redundant/excess capacity).

Initial plate trials with the addition of Initial plate trials with the addition of TBLS+® (creating a 4(creating a 4--basic crystal structure)basic crystal structure) ::

Improved plate porosity (from 44% to 53%) versus a standard 3Improved plate porosity (from 44% to 53%) versus a standard 3--basic structurebasic structureIncreased skeletal density (from 8.3 to 9.5 g/ml) Increased skeletal density (from 8.3 to 9.5 g/ml) stronger structurestronger structureLarger/more open and homogeneous pore structure with improved acLarger/more open and homogeneous pore structure with improved acid circulation id circulation (better cold cranking performance) (better cold cranking performance)

No No 1919 / 25/ 25--JulJul--05 05 –– VV 05050505

TBLS+TBLS+®® -- DevelopmentsDevelopments

Standard 3-basic cured neg. plate 4-basic cured neg. plate with TBLS+ ®

TBLS+® improves the physical properties of the negative active massimproves the physical properties of the negative active masspotential for mass reduction and significant cost savingspotential for mass reduction and significant cost savings

LocationsGroupTBLS+®Curing-process: Basics of Crystal Structure„State of the Art“: Curing and Drying„State of the Art“: Curing and DryingHow to obtain small sized tetrabasic lead sulphate crystals by use of seeding crystals?Application of TBLS+® to the Positive PasteTBLS+® - Commercial AdvantagesTBLS+® - DevelopmentsTBLS+® - Developments