Broad Base. Best Solutions.

Specialty Graphites for Energy Storage

GrAphITe MATerIALS AnD SySTeMS

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Specialty Graphite and Process Solutions – made by SGL Group.

Advanced material, equipment, and process solutions

Engineered for customers from more than 35 industries

Tailor-made from the most comprehensive product portfolio

In-depth production and material knowledge

Consistent high quality, performance, and service

Attractive total cost of ownership

Broad Base. Best Solutions.

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r Production of expanded graphite foils

BuSIneSS unIT GrAphITe MATerIALS AnD SySTeMS

Advanced solutions enable our customers to get ahead.SGL Group offers advanced solutions – even for challenging applications. We understand the specific requirements of our customers and combine in-depth production, material, and engineering knowledge with the most comprehensive specialty graphite portfolio. This makes us the partner of choice to leading companies in many different industries.

Exceptional resistance to heat and corrosion, high purity and mechanical strength are just a few of the outstanding properties which our materials offer. Specialty graphite products from SGL Group achieve optimal results where other materials fail. No matter what your specific requirements might be, we will identify the best solution from the most comprehensive range of specialty graphites.

Fine grain graphite: isostatic, vibration- molded, die-molded, extruded

Expanded natural graphite Carbon fiber-reinforced carbon (C/C) Soft and rigid graphite felts Silicon carbide-coated graphite materials

Additionally we use other materials like PTFE, silicon carbide, and specialty metals.

With our portfolio and technical know-how spanning more than 35 different industries, we engineer tailor-made solutions in close partnership with our customers.

SGL Group covers the entire value chain of specialty graphite production, including raw material processing, semi-finished product manufacture, precision machining, purification, and coating. When it comes to engineering of equipment and process solutions our service range makes the difference: We offer mechanical and process design, production, assembly, commis-sioning, and service – all from a one-stop shop.

This is how we control and ensure the consistent high quality, reliability, and performance of our products – and enable our customers to become more competitive. Challenge us. We are there for you worldwide.

Specialty graphite solutions for energy storage Energy storage systems are a key component in enabling the shift towards renewables making the energy revolution a success and ensuring the mobility of the future. With over 30 years of experience and an innovative product portfolio SGL Group is the preferred partner of leading companies worldwide.

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SIGRACELL® is the new brand name for our specialty graphite for energy storage.

Specialty graphites – made by SGL Group.Energy storage solutions.

Lead acid batteries (LAB)Lithium-ion batteries (LiB)

Lead acid batteriesLithium-ion batteries

Typical applications

Materials made of carbon and graphite

Productsof the SGL Group

SIGRACELL® expanded graphite powdersSIGRACELL® synthetic graphite powders

SIGRACELL® specialty graphites

Conductive additivesGraphite anode materialsCarbon composite anode materials

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With their high electrical conductivity, corrosion-resistance and material purity our specialty graphites meet the highest standards for quality, efficiency and environmental compatibility. This leads to an increase of performance and reliability of energy storage in a wide range of applications.

Based on our long-term experience and close development partnerships we provide tailor-made solutions to our customers.

SpeCIALTy GrAphITe SoLuTIonS For enerGy STorAGe

High-temperature batteries (NaNiCl2/NaS)Next generation batteries

Vanadium redox flow batteries (VRFB) Iron-chromium redox flow batteries (FeCrRFB)

Next generation batteriesFlow batteries

SIGRACELL® battery feltsSIGRACELL® graphite foilsSIGRACET® carbon papers

SIGRACELL® battery feltsSIGRACELL® bipolar plates

ElectrodesActive massesGas diffusion layers (GDL)

ElectrodesBipolar end-platesBipolar plates

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Graphite powder for lithium-ion batteriesOur cutting-edge battery lab creates tailor-made material solutions for our customers and development partners.

It enables us to develop and characterize new materials using particle engineering and working according to industry standards.

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Our graphite anode materials are used in lithium-ion batteries for mobile consumer appliances, electric vehicles and stationary energy storages for photovoltaic and wind. In order to spur technolo-gical progress even further, we invest in new generations of graphite-based anode materials and take active part in national and international networks.

For over 15 years we have been working in close cooperation with Hitachi Chemical Corporation, supplying our partner with anode material for lithium-ion batteries in consumer electronics, as well as for automotive and industrial applications.

SGL Group is one of the largest manufacturers of LiB anode materials and plays a major role in the advancement of LiB technology like C/Si compounds.

As a member of the Lithium-Ion Battery Competence Network (KLiB) we seek to strengthen Germany's competitiveness in this key technology. That’s why we are continuously working together with industrial enterprises and research institutions to improve battery cell performance, service life and safety. Further we invest in new generations of carbon and graphite-based battery materials for the next generation coordinated by our Energy lab and Application Center.

c LiB test cell production in a clean room atmosphere

c Electrode production at the Technology & Innovation Center for subsequent electrochemical characterization

SpeCIALTy GrAphITeS For LIThIuM-Ion BATTerIeS

Specialty graphites for lithium-ion batteries

b Anode material for lithium-ion batteries

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Partner for environmentally friendly energy storageWe have used our extensive understanding of specific customer requirements to refine our portfolio of carbon and graphite felts.

The result: SIGRACELL battery felts for energy storage. In Cellcube flow battery system, they contribute to the rapid supply of clean and emission-free energy. They also increase safety and storage ability.

This is just one example of an application-specific optimized solution from the SGL Group.

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Specialty graphites for lead acid batteriesHigh-performance, versatile, efficient.

We provide SIGRACELL battery additives for lead acid batteries. Highly conductive carbon additives with following advantages:

• High purity, especially very low levels of metal impurities• Excellent wettability• Easy to mix into the lead paste• Combination with conductive carbon blacks possible

All these key features lead to improved Dynamic Charge Acceptance (DCA) and a high cycling stability during high rate partial state of charge. The increased performance in high current applications gives a crucial improvement for lead acid batteries.

SGL Group’s combination of application-oriented research, extensive knowledge of materials and expertise in process technology make it the partner of choice in carbon compo-nents for energy storage.

All material development work starts with a well-founded understanding of the physical and chemical principles which determine the material’s subsequent use. SGL Group has its own energy laboratory with experienced specialists at its main technology and innovation research center, and works in close cooperation with leading universities and institutes. This allows us to incorporate new findings in the field of electrochemical energy storage directly into our material development.

SpeCIALTy GrAphITeS For LeAD ACID BATTerIeS

b Redox flow battery test cellin our in-house Energy lab

Material data for our SIGRACELL® battery additives

Typical properties UnitsExpanded graphite Synthetic graphite

GFG20 HP SG2μ SG4μ

Particle size distribution

D₁₀ µm 7 1 2D₅₀ µm 20 2 4D₉₀ µm 67 4 7

Specific surface area BET m2/g 23 30 – 40 15 – 20Ash content % < 0.1 < 0.05 < 0.05

Selected elements

Cd ppm < 1.0 < 0.1 < 0.1Cr ppm < 5.0 < 1.0 < 1.0

Cu ppm < 5.0 < 0.5 < 0.5 Fe ppm < 150 < 30 < 30

Mn ppm < 5.0 < 0.5 < 0.5Mo ppm < 0.5 < 0.5 < 0.5

Ni ppm < 5.0 < 2.0 < 2.0W ppm < 1.0 < 0.3 < 0.3

More detailed parameters like test of lead affinity and water consumption results are available on request. Please contact us!

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Flow batteries enable energy storage on a scale of kWh to MWh and provide the perfect solution for stationary applications. They are well-suited as temporary storage for grid stabilization, industrial back-up power, integration of renewables such as wind and photovoltaic as well as off-grid power supply for mobile radio transmitters and remote households. The main advantage of flow batteries is that they separate output (MW) and energy (MWh). The two can be adjusted independently of one another and are easily adaptable to the specific requirements at hand.

SGL Group ranks among the leading manufacturers of specialty graphites and graphite components for redox flow batteries.We have applied our long-term experience and close cooperation with customers to develop special materials and products for energy storage: SIGRACELL battery felts, bipolar plates and end-plates. Continuous improvement of our materials has significantly enhanced the performance and service life of our customers flow batteries.

Charge / Discharge

1 22 33

4455

c Schematic diagram of redox flow battery1 Membrane2 Permeable electrode3 Bipolar plate4 Storage electrode5 Electrolyte

Specialty graphites for flow batteriesReliable and easily adaptable to meet the specific requirements.

Specialty graphites for flow batteries

Applications SIGRACELL battery felts SIGRACELL bipolar plates and end-platesPermeable electrodes ○Bipolar plates ○

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Low cell resistivity and high electrolyte permeabil-ity are crucial factors for flow battery electrodes.Accordingly, the contact resistivity of the bipolar plate and felt electrode, as well as the permeability of the felt electrode largely depend on surface pressure and felt compression, and can be controlled by the compression rate:

• As the compression rate increases, resistivity decreases, as does permeability.

• Conversely, permeability and resistance increase as the compression rate decreases.

Inhomogeneity in the battery felt can lead to imper-meable areas reducing the overall performance of the system. Therefore SGL Group is continuously working on tighter tolerances for area weight and thickness of our battery felts. This enables our customers to optimize the compression rates to ensure the best battery performance possible.

SpeCIALTy GrAphITeS For FLoW BATTerIeS

c Flow battery components1 Ion-exchange membrane2 SIGRACELL battery felt3 SIGRACELL bipolar plate

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Relative electrical resistivity of graphite felt

100

80

60

40

20

050 10 15 20 25

Elec

tric

al re

sist

ivity

[%]

Compression rate [%]

Electrolyte permeability of graphite felt electrodes

Elec

trol

yte

perm

eabi

lity

[dar

cy]

Elec

trol

yte

perm

eabi

lity

[m2 ]

Compression rate [%]

Electrolyte permeability of graphite felt electrodes

Elec

trol

yte

perm

eabi

lity

[dar

cy]

Elec

trol

yte

perm

eabi

lity

[m2 ]

40

20

050 10 15 20 25 30 35

2.0E-11

1.6E-10

1.4E-10

1.2E-10

1.0E-10

0.0E-11

160

140

100

120

80

60

8.0E-11

6.0E-11

4.0E-11

3

Additional technical information please find in our White Paper: “SIGRACELL Carbon Components for Flow Batteries” on request.

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SIGRACELL® battery felts

Advantage of our complete inhouse value chain

raw feltfiber carbonizing carbon felt graphitizing graphite felt cut-to-size

Material data for our SIGRACELL® battery felt

Typical properties Units KFD2.5 EA GFD 2.5 EA GFD 4.6 EA GFA 6 EACarbon fiber precursor PAN PAN PAN RayonBulk density g / cm³ 0.1 0.09 0.09 0.08Nominal thickness mm 2.5 2.5 4.6 6.0Area weight g / m² 250 250 465 500Open porosity % > 90 94 94 95BET surface area m²/g 0.6 0.4 0.4 0.8Electrical resistivity I– Ωmm < 30 < 5 < 5 < 12Electrical resistivity II Ωmm < 10 < 3 < 3 < 4Area-specific resistance* I– Ωcm² – < 0.1 < 0.15 < 0.45Total impurities % < 0.6 < 0.05 < 0.05 < 0.1

II parallel to longitudinal direction of felt; I– vertical to longitudinal direction of felt; *compression to 80% of initial thickness

c SIGRACELL carbon and graphite felts

Permeable electrodes made of SIGRACELL carbon and graphite felts are the first choice for high-temperature batteries such as nickel-chloride and flow batteries. Our battery felts are used for anodes as well as cathodes. They facilitate an efficient charge exchange between the electrolyte and bipolar plate during battery charging and discharging. This is thanks to a unique combination of electrical conductivity, electrochemical stability, high porosity and good elasticity.

The sizes we provide are even enough to cover the needs of large-scale redox flow systems. We supply battery felts in standard sizes up to 1350 mm (53") in width in 25 m (82 ft) rolls. Beyond that, we produce carbon and graphite felts in customer-specific dimensions. Moreover we offer activated carbon and graphite felts which increases voltage, charge and energy efficiency. For further information please contact us.

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The main features that distinguish expanded natural graphite are excep-tional resistance to chemicals and good electrical conductivity. Together with high-grade fluoropolymers, our thin, high-density SIGRACELL bipolar plates can be used for a broad spectrum of applications. Thanks to their great resistance to corrosion, our SIGRACELL products are ideally suited for the demanding cell chemistry in battery systems. Redox flow batteries are but one example of the many uses for SIGRACELL plates. For bipolar end-plates as well as further grades please contact us.

c SIGRACELL bipolar plates made of expanded graphite (TF6/PV15) c SIGRACELL bipolar end-plates made of graphite composite material (F100)

SpeCIALTy GrAphITeS For enerGy STorAGe

SIGRACELL® bipolar platesand end-plates

Available sizes of our SIGRACELL® bipolar plates

Grade Thickness mm (in)

Length mm (in)

Width mm (in)

TF6 0.6 (0.02) 900 (36) 600 (24)PV15 0.6 (0.02) 900 (36) 600 (24)

We will also be glad to produce other formats upon.

Material data for our SIGRACELL® bipolar plates

Typical properties Units TF6 PV15Polymer type Fluoropolymer FluoropolymerDensity g / cm³ 1.75 1.65Thickness mm 0.6 0.6Tensile strength MPa 20 25Compressive strength MPa 150 170Electrical resistivity I– Ωmm < 10 < 10Area-specific resistance I– Ωcm² < 0.05 < 0.05Thermal conductivity I– Wm⁻¹K⁻¹ 6 6Thermal conductivity II Wm⁻¹K⁻¹ 300 300Permeability (helium) mg /(m²s) < 1 x 10⁻³ < 1 x 10⁻³Total impurities ppm < 150 < 150

II parallel direction of plate; I– vertical direction of plate

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We will find the best solution – in partnership with you.The fascinating potential of carbon as a material excites us and inspires us to develop optimum solutions in partnership with our customers.

With our comprehensive material portfolio and valuable specialist know-how, we can manufacture tailored products – even for the most challenging applications.

Consistently high quality, a global presence, innovative strength, and the extensive experience of our employees make us a reliable partner to our customers.

Whatever challenges you face, together we will find the best solution.

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b Anode material test productionat our Technology & Innovation Center

SGL Group – The Carbon Company.A leading global manufacturer of carbon-based products.Q Unique product portfolioQ Innovative technologies and solutionsQ Production sites close to sales marketsQ Technology & Innovation Center in Germany with international networks

We have wide-ranging expertise in raw materials, advanced manufacturing processes, and long-standing application and engineering know-how.We have a comprehensive portfolio of carbon, graphite, and carbon fiber products and our integrated value chain covers everything from carbon fiber to composites. With a global sales and distribution network and modern production sites in Europe, North America, and Asia, we are close to our customers throughout the world.

We use this broad base to offer our customers the best solutions possible. That’s how we live up to our claim: Broad Base. Best Solutions. This claim is also upheld by our corporate SGL Excellence philosophy of continuous improvement.

More information can be found by visiting: www.sglgroup.com C sglgroup sglgroup

SGL Group – The CArBon CoMpAny

Graphite Materials & SystemsSGL CARBON GmbH Soehnleinstrasse 8 | 65201 Wiesbaden/Germanywww.sglgroup.com/gms

europe/MIDDLe eAST/AFrICASGL CARBON GmbHDrachenburgstrasse 153170 Bonn/Germanysigracell-europe@sglgroup.com

ASIA/pACIFICSGL CARBON Far East Ltd.12 Fl, Shanghai Oriental Plaza31 Wujiang RoadShanghai 200041/PR Chinasigracell-asia@sglgroup.com

AMerICASSGL TECHNIC Inc.Polycarbon Division28176 No. Avenue StanfordCA 91355 Valencia/USAsigracell-americas@sglgroup.com

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® registered trademarks of SGL CARBON SE 05 2017/0.2 5NÄ Printed in GermanyThis information is based on our present state of knowledge and is intended to provide general notes on our products and their uses. It should therefore not be construed as guaranteeing specific properties of the prod-ucts described or their suitability for a particular application. Any existing industrial property rights must be observed. The quality of our products is guaranteed under our “General Conditions of Sale”.