LABAT’2017 June 13-16, 2017
Dr. Joseph Li Dr. Francois Henry Dr. Yujie Feng
How to Develop Best Graphite Products for Lead-Carbon Battery Applications
Superior Graphite Co. • • • • • •
Ownership- Family-owned & Partial ESOP Since 1917- Providing carbon-based solutions Employees- 260 globally Turnover> $100M- >35% non-North American sales Operations- 5 production sites; 2 R&D facilities ISO 9001:2008 Certification- USA and Europe; ISO 14001:2004- Europe
Locations World Headquarters, R&D, Chicago, Illinois Plants, Bedford Park, Illinois
Europe Headquarters, Sundsvall, Sweden Plants, Sundsvall, Sweden Offices Höhr-Grenzhausen, Germany
Plant Russellville, Arkansas
Plants Hopkinsville, Kentucky
Office Shanghai, China
Classification of Carbon & Graphite Unstructured Carbons
Coke Carbon Black Activated Carbon
Petroleum Coke Pitch Coke Secondary
Synthetic Graphite
Primary
2D Structure Graphene Nanotubes
3D Structure ---Diamond
Micro-crystalline Natural
Macro-crystalline
Flake Vein
Applications of Graphite in Energy Storage Characterization of Graphite
Typical Applications
Primary and Secondary Properties
• • •
Hexagonal structure with three dimensional ordering.
Performance additives in Advanced Lead-acid battery Anode Materials in Li-ion Battery Conductive additives • • • • • • •
• •
Alkaline battery, Li-ion battery Li-FeS2 battery Li-MnO2 battery Zn-Air battery NiCd battery Others
Bipolar plate materials in Fuel Cells Others
High Purity Graphite Needed for Advanced Batteries Example: Graphite in advanced Lead acid battery applications: Graphite with high impurities show significant higher gassing
Carbons in negative plates
Carbon contents
Expanded Graphite#1 Expanded Graphite#2 Expanded Graphite#3 Note:
1.50% 1.50% 1.50%
Metal impurity contents / ppm Fe 2370 340 21
Cu 56 29 ★
Sb ★ ★ ★
★: metal impurity content ＜10 ppm.
Mn 53 ★ 28
Co ★ ★ ★
Ni 23 ★ ★
From J. Hu, etc. Int. J. Electrochem. Sci., 11 (2016) 1416-1433
Purification Technologies •
Chemical Purification Technologies (e.g., acid leaching technology):
•
Remove impurities including metallic elements with high concentration of either of acids (HCl/HF/H2SO4) or alkaline salts Simplest form of purification and Economical Potential chemical residues in graphite Environmental concerns
Thermal Purification Technologies:
Remove impurities including sulfur and metallic elements; Decomposition and carbothermic reduction of impurities/metal oxide. Impurity vapor diffuse outward between the cleavage planes of carbon and carried out by fluidized bed furnace flue gas.
Thermal Purification Technologies Acheson Process Horizontal process Moderately efficient High-purity Environmentally not unproblematic
Conductive Graphite Core
Superior Graphite EFB Technology
SiC + SiO2 + C SiC Coke Graphite SiO2 + C SiO2 + SiC + C
Removable Side Wall
Vertical process flow High throughput High-purity Environmentally friendly
SG Electro-thermal Fluidized Bed (EFB) Technology
• • • • • • •
Continuous processing capability Consistent quality Precise control of the process Ultra-high Purity - +99.95% C Improved conductivity Economic effectiveness Purify a wide range of carbons; Natural and synthetic graphite Carbon black Coke variants
Thermal Purification at Superior Graphite Flake graphite extracted from ores and further upgraded to 95+% carbon Thermally Purified flake upgraded to 99.9+ % carbon
Thermal Purification
Effects of EFB Purification Process Symbol
Aluminum Arsenic Chromium Cobalt Copper Iron Lead Molybdenum Nickel Vanadium Total
Al As Cr Co Cu Fe Pb Mo Ni V
Raw material (ppm) 1570.3 4.5 0.7 0.7 13.9 2444.9 1.7 24.9 1.9 1.4 4064.9
EFB Purified (ppm) 5.6 <1.0 <1.0 <1.0 <1.0 26.5 <1.0 2.2 1.5 1.2 37.0
Chemical Purified 599.95 (ppm) 7.0 <1.0 <1.0 <1.0 <1.0 115.0 <1.0 <1.0 <1.0 <1.0 122.0
5000
5000
4000 3300
Fe Content, ppm
Elements
3000
2000
1000
450 375 6.3 16
0
10
Fe Content After Purification
Canada China Mozambique
Source of the Natural Crystalline Graphite Fe Content After Purification
market available products
Fe content before purification
19
Ceylon
Fe content before purification
Applications in Lead-carbon Batteries Traditional Lead-acid Battery + PbO2
Lead-Carbon Battery for Start-Stop Technology + Pb with Pb
Carbon/Graphite
• Significant Cycle Life Improvement; • Improving dynamic charge acceptance; • Slow down internal resistance increase;
PbO2
graphite /carbon
Carbon/Graphite Properties and Effect on Battery Performance. • Electrical conductivity It is one of the most important carbon characteristics. Carbon conductivity is the parameter that allow it to work as conductive bridge among the numerous lead sulphate crystals that develop during battery operation at partial state of charge like in HEV use. Influence of conductivity is clearly seen on high rate discharges at low temperature in which it counteract the deleterious effect of distortion of lead structure caused by carbon addition. Other aspect with high influence of carbon conductivity, is the performance on cycle life. When adding high conductive graphite like expanded graphite or conductive carbons, a noticeable and consistent increase of cycle life is obtained.
• Specific Surface Area This is a carbon parameter directly related with battery charge acceptance. Charge acceptance have an almost direct relation with the SSA of the carbon added. The positive effect of carbon SSA, is also seen on cycle life. As a consequence of increased charge acceptance, the battery is capable of accepting charge in a more efficient way markedly improving the performance on cycle life, but could cause potential high gassing.
• Particle size It is directly related with the degree of distortion of the lead structure. The lower the particle size, the lower the distortion. Its effect has been tested on project 1012M in which working with pre-dispersed graphite, very high durations on High Rate Low temperature were obtain.
Effects of Processing Technologies on Graphite Properties Concept of Investigation •Milling and Processing of high Purity Flake Graphite With a Variety of Processing Systems •Dry Blending of Graphite with Non-conductivity Material at Various Concentrations •Determination of Resistivity under Constant Load by Means of Two Point Method High Purity Flake Graphite >99.9%C, Lc>300 nm
Hammer Milling Air classic Milling Fluidized Bed Milling Exfoliation /Air milling Super Exfoliation /Air milling
Blending With Non-conductivity Material MnO2
Measurement of Electrical Resistivity
21-Jun-17/MTW
14
Mill and Processing Technologies Hammer Milling
Sample 1
Air Classic Milling
Sample 2
Mill and Processing Technologies (Cont.) Fluidized Bed Milling
Sample 3
Exfoliation/Expansion Air Milling
Sample 4
Physical Properties in Summary
Product Sample Sample Sample Sample Sample
1 2 3 4 5
Particle Size d50 (micron) Hammer Milling ~ 10 Air Classic Milling ~ 10 Fluidized Bed Milling ~ 10 Exfoliation/Air Milling ~10 Super Exfoliation/Air Milling ~10 Type of Milling
Bulk Density (g/ccm) 0.16 0.09 0.06 0.05 0.045
SSA BET (m2/g) ~9 ~7 ~9 ~ 20 ~ 23
Electrical Resistivity vs. Processing Technologies
SG Product Portfolio – for Lead-acid Batteries FormulaBT® for Lead-acid Batteries Negative Active Materials Additives
FormulaBT® LBG8004
FormulaBT® ABG1010
FormulaBT® ABG2010
FormulaBT® ABG1010
FormulaBT® LBG8004
Expanded Natural Graphite
Purified Natural Graphite
FormulaBT® ABG1025
FormulaBT® 2939APH
Expanded Natural Graphite
Purified Flake Graphite
FormulaBT® 2939APH
FormulaBT® ABG1045 Expanded Natural Graphite
FormulaBT® ABG2010 Super ExpandedNatural Graphite
Commercial Available Products
Power Assist Cycle Life
End of discharge voltage and electrical resistance
Effects on Cycle life improvement by graphite type EG - expanded graphite; SG - synthetic graphite FG – flake graphite; CCB – conductive carbon black From M. Fernández, J. Valenciano, F. Trinidad, N. Mu˜noz, Journal of Power Sources 195 (2010) 4458–4469, project funded by ALABC
Discharge Power vs. SoC (6V 10Ah modules) ABG1010 improved high rate low temperature discharge power
1.5% ABG1010 1% CB1+1% ABG1010 1% CB2
From Exide research group at Spain (Melchior Fernandez), project funded by ALABC
Summary • Graphite properties, e.g. purity, electric conductivity, specific surface area as well as particle size, have significantly effects on Lead-acid battery performance. • Superior Graphite’s Electro-thermal Fluidized Bed (EFB) technology has been demonstrated to be the most capable and efficient route to purify carbon and graphite materials for advanced battery applications. • Processing technologies have large effects on graphite properties. • Expanded (exfoliated) graphite products, produced with SG’s EFB technology, show high purity, excellent electric conductivity and high specific surface area, and best suitable for Lead-carbon battery application.
Thank You for Your Attention
