Lead-Acid Battery I
Bahtiar Yulianto
May 2016
Lead Mining Process
Lead Manufacturing Process
Mining the ore
Concentrating the ore
Flotation
Filtering
Roasting the ore
Blasting
Refining
Costing
Pb contains several metal impurities such
as Cu, Ag, Au, Zn, Sn, As, and Sb, which have
to be removed. The final purification is carried
out by electrolytic rafination using massive cast
Pb anodes. This procedure yields a cathodic
deposit with 99.99% Pb. It can be further
purified electrochemically to obtain Pb with
impurities level below 1 ppm.
K Maksymiuk, J Stroka, and Z Galus,
University of Warsaw, Warsaw, Poland
Lead Minerals
Lead (Pb) Mining in Indonesia
Lead Mining in Indonesia
 DI. Aceh (K. Beureung, K. Isep, Pasir Putih, Lokop)
 Sumatera Utara (Bululaga, Nias, Sihajo, Nusa Bargot, Muara Soma, Ulu Aek Paneme Estella,
Paguran Si Ayu, Bukit Pionggu, Malilir, G. Marisi, Sidingin)
 Sumatera Barat (Sumpu, Balung, Batang Bio, Bata Menjulur, Lubuk Selasih, S. Talang, S. Pagu,
Bulangsi, Tepan, Mangani, G. Arum)
 Bengkulu (S. Ipuh Panjang, G. Batu bertulis, Aer Penejun, Aer Saleh, Aer Piatu, Aer Bagus,
Tabak Tempilang, Aer Anget, Aer Limpure, Cepei, Aer Kidurung, Aer Loh, Muara Impu Tanah,
Lebong Simpang, Lebong Donok, Lebong Sulit, Lebong Kandis, Simau, Tumbang Sawah)
 Sumatera Selatan (S. Tuboh, Aer Kukus, Aer Seri, Bukit Lajah, Kikim Besar)
 Lampung (Rajabasa, G. Rantai)
 Bangka Belitung (Tanjung Pandan, Membalong, Dendang, Gantung, Manggar, Kelapa Kampit)
 Banten (Cirotan, Cikotok, Panggarangan)
 Jawa Barat (G. Parang, G. Sawal, Tasikmalaya, Cianjur)
 Jawa Timur (Janglot, Dawuhan, Kedungpring, Tegalrejo, Domasan, Kalitelu, Kasinan,
Brungkah, Batu Ulu)
 Kalimantan Barat (Mandoe, Bengkayang, S. Samarayak)
 Kalimantan Tengah (Sampit)
 Kalimantan Timur (S. Mara)
 Sulawesi Selatan (Sasak, Masupu, Bobohan)
 Nusa Tenggara Barat (Lentek Desa Rembitan)
 Nusa Tenggara Timur (Hulu W. Rango, Omesuri, Laibunggi, Ujung Selatan Bag. Barat P. Sumba,
Worgilip-Prabur, Maikawada, Taneman, Kuneman, Mamenang, Pido, Taramen, Wakapsir)
What is battery ?
Battery does not store electricity, but rather it stores a series of chemical,
through a chemical process electricity is produced.
Basically, two different type of lead in an acid mixture react to produce an
electrical pressure called voltage.
This electrochemical reaction changes chemical energy to electrical
energy and is the basis for all automotive batteries
(Kevin R Sullivan, Professor of Automotive Technology Skyline College)
The purpose of battery ?
(Kevin R Sullivan, Professor of Automotive Technology Skyline College)
The battery supplies electricity when the :
ENGINE IS OFF
Electricity from the battery is used to operate the lighting, accessories, or
other electrical systems when the engine is not running
ENGINE IS STARTING
Electricity from the battery is used to operate the starter motor and to
provide current for the ignition system during engine cranking. Starting
the car is the battery’s most important function.
ENGINE IS RUNNING
Electricity from the battery may be needed to supplement the charging
system when the vehicle’s electrical load requirements exceed the
charging system’s ability to produce electricity. Both the battery and the
alternator supply electricity when demand is high.
Batteries
Primary or Secondary
(Kevin R Sullivan, Professor of Automotive Technology Skyline College)
Primary Cell
The chemical reaction totally destroy one of the
metals after a period of time, primary cells can not
be recharged. Small batteries such as flashlight
and radio batteries are primary cell.
Secondary Cell
The metal plates and acid mixture change as the
battery supplies voltage. As the battery drains the
metal plates become similar and the acid strength
weakens. This process is called discharging. By
applying current to the battery in the reverse
direction, the battery materials can be restored,
thus recharging the battery. This process is called
charging. Automotive lead acid batteries are
secondary cells and can be recharged.
Car Electrical System
Market study by ENERSYS®
Battery Classification
Lead Acid Batteries
Starting, Lighting, and
Ignition (SLI)
Motive Lead Acid (MLA)
Stationary Lead Acid
(SLA)
Consumer automotive
applications
Heavy Duty vehicle
applications
Telecommunication
applications
Mining applications
Data Communication
applications
Marine applications
Utility applications
Other applications
Railroad applications
Emergency Lighting
applications
Other automotive
applications
Other applications
Lead Acid Battery Market : Market Segmentation (World 2001,
source : Frost and Sullivan)
Security applications
Other applications
VRLA Batteries
Pure Lead Grid
Standard Calcium
Motive Lead Acid (MLA)
Starting, Lighting, and
Ignition (SLI)
Stationary Lead Acid
(SLA)
Standard Antimony
Standard Calcium Low
Antimony
Low Antimony
Flooded Batteries
Lead Acid Battery families of flooded and VRLA Batteries, grid alloys and application field
Lead Acid Battery Manufacturing Process
Lead Acid Battery Component
MOLL
Ion permeable and resistant to H2SO4,
O2 and H2 attack
Lead Acid Battery Standard
- JIS Standard (Japanese Industrial Standards)
JIS D5301-2006
- DIN Standard (Deutsches Institut für Normung", meaning
"German institute for standardisation)
DIN EN 50342-1
- SNI Standard (Standar Nasional Indonesia)
SNI 0038:2009
- IEC (Electrical Characteristics)
IEC 60095-1 : 2006
IEC 60095-2 : 2006
- GSO Standard (GCC Standardization Organization)
GSO 35/2007
- SLS Standard (Sri Lanka Standard)
SLS 1126 Part 1 : 2004
- SAE Standard (Society of Automotive Engineers)
SAE J240
- EN Standard (European Standard)
EN 61429
Starting Lighting Ignition (SLI) Lead Acid Battery Construction
NGS INDOBATT INDUSTRI PERMAI
Negative Pole/terminal
Plate strap
Positive Pole/terminal
Dop
Polypropylene Cover
Polypropylene
Container
Fiber glass mat
Micro porous
Separator
Lead Connector
Negative Plate Pb
Positive Plate PbO2 wrapped
in separator
Lead Acid Battery Construction
Grid – Enveloping – Separator & Fiberglass mat
Grid
Enveloping
Separator & glass mat
Grid Casting Machine - Wirtz
Wirtz Automotive Gravity Casting Machine
Wirtz Continuous Grid Casting System
Wirtz Continuous Grid Punching System For
Positive Plates
Grid and small part
Center Lug Grid
Side Lug Grid
The battery capacity is increased because of the
increase in surface area. More plate surface area
means the battery can deliver more current
LEAD ALLOY
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•
The grids makes an important part of the storage cell which act as support
for the active materials of plates and conduct the electric current developed.
It also plays an important role in maintaining uniform current distribution
throughout the mass of the active material.
Grids must be mechanically proof and positive grid must be corrosion proof
(Petr Krivik & Petr Baca). Corrosion converts lead alloy to lead oxides with
lower mechanical strength and conductivity.
Grids are made from Lead Alloys (Pure Lead will be too soft), it is used PbCa or Pb-Sb with mixture of additives as Sn, Cd, Se, that improve corrosion
resistance and make higher mechanical strength.
Grid corrosion is highly increased
Grid Casting Machine - Wirtz
Grid Size Capacity
Production
Wirtz Automotive Gravity
Casting Machine
Trim Width: 4.250” (108mm)
min to 6.735” (161mm) max
Lug to lug: 7.375” (187mm)
min to 13.625” (346mm) max
Grid Thickness: 0.040”
(1.02mm) min to 0.188”
(4.77mm) max
Speeds up to 18 casts per
minute. One operator, (3)
machines, up to 35,000 grids
per (8) hour shift.
Wirtz Continuous Grid Casting
System
Maximum Casting
Width: Depends on Concast
System.
Grid Design: Per customers
specifications
Thickness: Per customer
specifications (+/- 0.0125mm)
Production speeds up to 75
feet per minute (23 meters
per minute), dependent on
alloy, grid design, thickness,
and other parameters.
Wirtz Continuous Grid
Punching System For Positive
Plates – Conpunch CP-13200
Maximum Product
Width: 11.81 in. (300mm)
Grid Design: Per customers
specifications
Thickness: Per customer
specifications
Production speeds up to 250
stroked per minute,
dependent on strip alloy, grid
design, thickness, and other
parameters.
Gravity Casting Accessories
Sodium Silicate
150 ml
Water
5 liter
X500 MOLD COAT
500 gram
Mixing
Acid Tank
Expand the paste and giving it great
porosity, supplies a necessary binding
cement so the dry plate can be
handled without loss of material
SOVEMA Blade Type Mixer
1,000 KG
Water Tank
Act as lubricant producing lighter paste
Lead Oxide Silo
Grinding and surface
oxidation to pure
lead ingots
Mixing Tank
Pasting line
Flash Drying Oven
Mixing
Positive Active
Material
Negative Active
Material
Lead Powder
Lead Powder
Durafloc
Durafloc
Water
Water
Sulfuric Acid
Sulfuric Acid
Barium Sulfate
Sodium Lignosulfonate
Expander
Stearic Acid
Lead Oxide
Processes on the Pb/PbO2/PbSO4 electrode in H2SO4 solution
Oxygen evolution at PbO2 electrode
MIXING
Ratio of H2SO4/Lead Oxide
Alpha & Beta PbO
It depends on H2SO4/LO ratio (LO is the oxidized lead powder), temperature, additives and time of mixing. It
has been established that the paste is a non-equilibrium system consisting of crystalline basic lead sulfates
and oxides, and amorphous sulfate-containing components. Depending on the temperature of preparation
pastes with the following compositions are obtained :
At to<60oC
H2SO4/LO ratio up to 12%. The paste contains 3PbO.PbSO4.H2O (3BS) + tet-PbO + orthorhombic-PbO + Pb.
Maximum content of 3BS is obtained at 10% H2SO4/LO.
Over 8% H2SO4/LO ratio, mostly PbO.PbSO4 (1BS) is formed.
At to>70oC
H2SO4/LO ratio up to 7%. The paste contains 4PbO.PbSO4 (4BS) + tet-PbO + orthorhombic-PbO + Pb.
Maximum content of 4BS is obtained at 6.5% H2SO4/LO. At beginning of mixing 3BS and orthorhombic-PbO
are formed first. Then (3BS) + tet-PbO + orthorhombic-PbO react and 4BS is formed. 4BS nucleation is the
slowest process. It depends strongly on temperature. In the presence of surface active additive(s)
(expander(s)) 4BS and orthorhombic-PbO are not formed at all.
H2SO4/LO ratio between 7% and 12%. The paste contains 3BS + 1BS + tet-PbO + orthorhomb-PbO.
With time of stirring 3BS crystals grow up to 2-4 μm in size and 4BS ones reach sizes of up to 20-50 μm.
PASTING
-
+
Pasting Machine
Basic lead sulfates are formed during
this stage
Chemical of active material resistant to
H2SO4 solution
Flash Drying Oven
The evaporation of water gives a desirable porosity
If too much water is evaporated during the rather short
period of flash drying, cracks will occur in the material (R
Wagner, MOLL Accu Elsevier 2009)
PASTING
PASTING
3BS was observed to be dominant when pasting was carried out at lower
peak temperature (Int J Electrochem Sci Vol 6, 2011).
The initial reaction of sulfuric acid with lead oxide (equation 1) leads to
normal lead sulfate and heat evolution. Under the influence of excess lead
oxide and water this is not stable, so converts into basic sulfate, either tribasic
(2) or tetrabasic (3) according to
PbO + H2SO4 ↔ PbSO4 + H2O
(1)
PbSO4 + 3PbO ↔ 3PbO.PbSO4
(2)
PbSO4 + 4PbO ↔ 4PbO.PbSO4
(3)
Tribasic sulfate is crystallized as small needles with high specific surface and
formed, roughly speaking, below 70 oC.
Tetrabasic sulfate forms more bulky crystals at temperatures above 70 oC.
(Lead Acid Battery Formation Techniques – Digatron)
CURING
3BS Vs 4BS (R Wagner, MOLL Accu Elsevier 2009)
3BS
4BS
Shorter battery
cycle life
Crystal much larger therefore the formation is much
more difficult and longer. It means that either lower
initial capacity has to be accepted or significantly
longer formation time is needed.
Reacts relatively
fast to lead
sulfate
Reacts at first mainly to 1BS and afterward some of
it much more slowly to lead sulfate
Higher Capacity
It gives more robust crystalline structure which
reduce the shedding of positive material during
cycling resulting in a better cycling performance.
This is particularly important for positive plates with
Lead – Calcium grid alloys.
Crystal smaller
therefore the
formation is
more easy and
shorter
Action to reduce 4BS :
- Control process parameters of the curing process
so that smaller 4BS crystals appear.
- Add certain chemicals to the paste that would limit
the growth of the 4BS crystal.
- Using two step curing program (first step at 70
Deg C in just a few hours, second step at 50 Deg C
High formation
efficiency, Lead
Dioxide content
> 90%
Low formation efficiency, Lead Dioxide content <
80%
Mixed
Formation efficiency than just 4BS
Cycling performance than just 3BS
Lead dioxide content < 90%
Curing and Drying
Controlled the temperature, humidity and duration of the process
(R Wagner, MOLL Accu Elsevier 2009)
Pallets with plates are placed in a high humidity chamber and left to cure at
35 ⁰C for 48-72 h. During the curing process, lead in the paste is oxidized, the basic lead
sulfates re-crystallize and the plates are then dried to moisture content <0.5% (Pavlov 109).
The amount of the basic sulfates depends on the paste recipe or more precisely on the
amount of sulfuric acid added during mixing. The portion of 4BS depends on the
temperature of the curing process. This compound will not appear as long as the
temperature is kept below 70 ⁰C (R Wagner, MOLL Accu Elsevier 2009)
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Curing and drying of plates for lead acid batteries can be managed to become tetra
basic or tri basic lead sulfate depending on the process parameters (Dr Nitsche)
Higher surface area would accelerate the process of acid diffusion into the plate and
within it, thereby improving the high rate performance of battery (Int J Electrochem Sci Vol 6,
2011).
The surface area (sq m/g) get reduced with increasing Acid/Oxide ratio (Lead
Sulphates bulkier than PbO).
The temperature is responsible for the composition of cured plates, such plates cured
at high temperature (more than 70oC) resulting in mainly tetrabasic lead sulphate
4PbO. PbSO4 (4BS) behave markedly different to those cured at low temperature
having only tribasic lead sulphate 3PbO. PbSO4. H2O (3BS)(11,12). The surfaces are
of active material and depend on curing temperature, as the suitable temperature in
curing process is around (56-65oC)(13) (Bakhtiar Kakil Hamad, R Wagner, MOLL Accu Elsevier
2009). While the reduction in surface area with increase in curing temperature can be
attributed to the growth of 3BS/4BS. The higher Peak Temperature and Curing
Temperature have shown a similar effect.
3BS yields higher capacity and 4BS provides higher cycle life.
Paste morphology is looked at from view point of crystal type 4BS/3BS crystal growth
specially its length (um), phase distribution and packing intensity.
Temperature above 60 oC should be avoided in the production of positive plates i.e.
paste preparation, curing and drying (Dr. Reiner Kiessling, Lead Acid Battery Formation
Techniques)
Composition of the cured material (R Wagner, MOLL Accu Elsevier 2009 ) :
- Basic lead sulfates (3BS : 3PbO.PbSO4 or 4BS : 4PbO.PbSO4)
- Lead Oxide (α-PbO)
- Small percent of free lead (Pb)
- Monobasic lead sulfate (1BS : PbO.PbSO4)
- Lead Carbonate/Hydrocerussite (Pb3(CO3)2(OH)2)
- β-PbO
After curing and drying, parameter should be checked are :
- Remaining free lead content
- Moisture content
- Lead carbonate
- Density
- Porosity
- Pore size distribution
- BET surface
- Ratio 3BS and 4 BS
CURING
Detchko Pavlov Lead Acid Batteries Science and Technology
CURING
R Wagner, MOLL Accu Elsevier 2009
Characteristic data of the cured plate
Crystal Size
Crystal
Structure (XRay)
Pore Diameter
(μm)
BET Surface
(m2g-1)
High
Large
4BS
6-11
0.3-0.4
Medium
Large/Small
4BS + 3BS
0.7-0.8
0.9-1.0
Low
Small
3BS
0.4-0.6
1.2-1.3
Curing
Temperature
BET : Brunauer Emmett and Teller
CURING
Detchko Pavlov Lead Acid Batteries Science and Technology