1. Combined Influence of Organic Expander and High Surface-Area Carbon Black on Capacity, Dynamic Charge Acceptance, Cold CrankING and PARTIAL STATE OF CHARGE Life ON LEAD-ACID BATTERIES
Slide 1 Title
Thank you, and good afternoon, on behalf of Borregaard LignoTech, it is my pleasure to present our investigation into the combined influence of organic expander and high surface area carbon on the performance of lead batteries.
T. McNally1, J. Poirier1, S. Shafarik1
1Borregaard LignoTech, Rothschild, WI,USA

2. 4/9/2019
Vanisperse® Products
Development of Borregaard LignoTech family of organic expander additives:
Vanisperse® A Vanisperse® HT-1 Vanisperse® AT Vanisperse® DCA
Overall Excellence High Temperature Life Cold Crank Enhancement Increased charge acceptance
For all applications Low Water Loss Increased Dynamic Charge Acceptance
Cold Crank
Capacity
Vanisperse products are high molecular weight anionic organic molecules, water soluble, and belong to the sodium lignosulfonate class of substances.
Slide2 Product List
Borregaard LignoTech produces a family of organic expander products under the Vanisperse tradename. They are listed with their strengths on this slide. In this presentation we will focus on the interaction between Vanisperse A and Vanisperse DCA with carbon.
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3. Outline Organic expander function.
4/9/2019
Outline
Organic expander function.
Interaction between organic expander and high surface area carbon black.
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4. Organic Expander Function – Semi-Porous Membrane
Through hydrophobic interactions Vanisperse (expander) adsorbs onto crystals with the charged sulfonic groups oriented to the electrolyte.
By steric hindrance and charge repulsion, Vanisperse prevents electrolyte from directly contacting and reacting with lead and thus preventing negative electrode passivation. (b) (c).
However, the membrane structure must be semi-permeable to enable diffusion of lead ions into the electrolyte during discharge, and then back to the electrode surface on charge.
The membrane must also be dynamic, able to disassemble as the lead reacts and dissolves upon discharge, and then reassemble on the lead sulfate crystal as they grow, and visa-versa upon charge.
Slide 4: Expander Function – Semi-Porous Membrane
Vanisperse adorbs onto lead and lead sulfate by means of hydrophobic interactions, forming a membrane like structure, with the charged sulfonic groups oriented to the electrolyte.
By steric hindrance and charge repulsion, Vanisperse prevents electrolyte from directly contacting and reacting with the lead, thus preventing negative electrode passivation.
However, the membrane must have special properties. It must be semi-permeable to enable the diffusion of lead ions into the electrolyte during discharge, and then back to the electrode surface during charge.
The membrane structure must also be dynamic. It must be able to disassemble as the lead reacts and dissolves, and then reassemble on the lead sulfate crystals as they grow, and then visa-versa upon charge.
“Lead-Acid Batteries”, D. Pavlov, Elsevier, Chapter 7, p. 318.
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5. Organic Expander Function – Surface Area
4/9/2019
Organic Expander Function – Surface Area
Organic battery additives, such as Vanisperse®, enhance performance of the negative electrode.
NAM surface area increases linearly with increasing Vanisperse® dosage.
No Vanisperse® added % Vanisperse® A D. Boden et. al.
Slide 5: Organic expander Function – Surface area – Kuala Lampur
It is not entirely understood how organic expanders enhance battery performance. But what can be measured is that by adding Vanisperse, the resulting sponge lead crystal size decreases substantially as evident in the image at right. An ALABC funded Investigation found that surface area increases linearly with organic expander dosage as evidenced in the graph on left.
ALABC: Project 1012J
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6. Vanisperse® Dosage Effect on Capacity, Cold Crank, Charge Acceptance
4/9/2019
Vanisperse® Dosage Effect on Capacity, Cold Crank, Charge Acceptance
Vanisperse DCA
Vanisperse A
Vanisperse A
Vanisperse DCA
Performance varies with the type of organic additive
Performance/dosage response can be simple, such as the linear relationship for charge acceptance, or
The performance dosage relationships can be described by parabolic curves, as for capacity and cold crank
Second order polynomial relationships, and with different optimal dosages
Optimal dosages: Cold Crank: Capacity:
Vanisperse® DCA: ~0.30% Vanisperse® DCA: ~0.30%
Vanisperse® A: ~0.22% Vanisperse® A: ~0.15
Carbon Black: 0.1% low surface area, 75 m2/g
2 V cell (2 pos. & 1 neg.)
Slide 6: Organic Expander Function – Organic/Dosage/Performance – Van A, Van DCA
In this study using negative limited 2 V cells, we see that the performance-dosage relationship varies with the type and dosage of the organic expander.
With charge acceptance the relationships are linear, and their slopes vary with the organic type.
For capacity and cold crank, the relationships are parabolic curves. These are 2nd order polynomials with different optimal dosages.
As you can see, Vanisperse DCA tends to perform better at the dosages typically employed. Due to its excellent charge acceptance, Vanisperse DCA is our recommended product for EFB batteries. It has the best charge acceptance, capacity, and cold crank in the dosage range of 0.2% to 0.3%.
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7. Outline Organic expander function
4/9/2019
Outline
Organic expander function
Interaction between organic expander and high surface area carbon black.
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8. Summary of Investigations: One-Variable Experimental Designs
4/9/2019
Summary of Investigations: One-Variable Experimental Designs
2. Investigations where the organic expander content was held constant while the carbon content was varied.
As carbon content increased, charge acceptance and PSoC life increased, however cold crank decreased and water loss increased.
3. Investigations where specialty black content was held constant while the organic expander content was varied. Projected optima represented by the circle.
Very complicated responses. Charge acceptance and PSoC were improved compared to control while cold crank and water loss were satisfactory.
1. Region of traditional compositions: Low dosages
of low surface area blacks and low dosages of organic expander.
Slide 8 Summary of One-factor studies
In the development of EFBs, manufacturer’s realized that traditional SLI expander combinations, represented by the blue rectangle at the lower left, couldn’t provide the required charge acceptance or suitable PSOC life. The remedy was to add large doses of high surface area carbon as represented by the vertical purple line. As carbon content increased, charge acceptance and PSOC life improved, but unfortunately, this also resulted in poor cold crank, poor high rate discharge, increased water loss, and shortened high temperature life. By increasing the Vanisperse A content, designated by the green, blue, and yellow horizontal lines, these essential properties were restored. Subsequent investigations found performance further enhanced by using Vanisperse DCA.
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9. Vanisperse® A and Vanisperse® DCA Adsorption Interaction with Carbon
4/9/2019
Vanisperse® A and Vanisperse® DCA Adsorption Interaction with Carbon
Slide 9. Vanisperse Adsorption onto Carbon and surface area effect
Vanisperse products are known to adsorb onto carbon. We studied the adsorption between Vanisperse and several carbons. The carbons are designated by their surface area in the vertical brown column. The amount of a particular Vanisperse adsorbed is presented at the carbon’s right. It is evident that the amount adsorbed varies depending on the type Vanisperse and increases with carbon surface area. High surface area carbons adsorb a significant amount, and at high loadings reduce the effective dosage well below the nominal dosage.
The amount adsorbed varies with both the type of Vanisperse and the surface area of the carbon.
With high surface area blacks, the amount of Vanisperse adsorbed is significant.
- Effective dosage: The portion of the organic expander not adsorbed onto carbon and is available to perform organic expander functions.
- Consequently, the organic expander’s effective dosage can be significantly less than the nominal dosage.
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10. Vanisperse® DCA and Vanisperse® A Interaction with Carbon Black
4/9/2019
Vanisperse® DCA and Vanisperse® A Interaction with Carbon Black
At low ratios of low surface area carbon black to Vanisperse®, the effective Vanisperse® dosage is close to the nominal Vanisperse® dosage.
However, at high ratios of high surface area carbon to Vanisperse®, the effective dosage of Vanisperse® has decreased below optimal dosage.
- Hence, the Vanisperse® dosage has to be increased to retain useful cold crank performance.
Slide 10. Effective dosage and Vanisperse A CCA as function of effective dosage.
We calculated the effective dosage for several EFB expander combinations and found that the Vanisperse A dosage could be reduced by half, while the Vanisperse DCA dosage could be reduced by two-thirds. These values are presented in green column.
The impact on cold crank is presented in the figure at right, where the nominal Vanisperse A dosage is 0.2%. Adding a high surface area carbon at a 4:1 ratio, reduces cold crank about 14%. Adding it at a 6:1 ratio reduces it by almost 30%.
This explains why increasing the Vanisperse A dosage restored the cold crank performance.
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11. Central Composite Response Surface Design
4/9/2019
Central Composite Response Surface Design
2 V cell: 2 positives and 1 negative
Two variable factors: Organic expander additive and carbon black
Test groups: 9 different pairings of carbon black and organic expander
Range for organic expander: 0.12% to 0.50%
5 different levels
Range for carbon black: 0.15% to 0.85%.
5 different levels Each combination of carbon black and organic expander was replicated.
The center point combination was replicated 4 times.
Design capable of defining interactions and polynomial relationships.
Each performance response is defined by 20 data points.
ANOVA was used to determine error, significance and response model.
Goals:
Define optimal dosage region yielding improved charge acceptance and PSOC life and suitable cold crank relative to control cells.
Characterize performance-dosage relationship for each response.
Slide 11: Central Composite Response Surface Design Slide 18 from Kuala L.
For both the carbon black and the organic expander there exists a dosage conundrum. The organic expander must be present in sufficient quantity to increase the hydrogen evolution overpotential, to suppress hydrogen generation and water loss and prevent lead sulfate passivation. But not too great a quantity as to suppress charge acceptance, unacceptably. It must also be present in sufficient quantity to promote strong cold crank, strong high rate capacity and long life.
The carbon additive must be present in sufficient quantity to depolarize the negative electrode to promote useful charge acceptance, but not too great a quantity as to promote hydrogen evolution and water loss. Finally, the situation is further complicated, due to the adsorption of the organic additive onto the carbon.
An effective technique to manage these complexities is with statistical design of experiment software. We selected a central composite response surface design, and used ranges that encompass the dosages of the previous 1-factor studies. The well-known power of this statistical approach is that it will evaluate each factor at 5 levels with spacing such that curvature for each response can be determined. Nine combinations of carbon and organic expander were investigated. A schematic representation of the additive combinations is presented on this slide.
The design contains a central point plus 8 points radiating at specific coordinates. The center point was replicated 4 times and the others were each replicated once.
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12. 4/9/2019
Vanisperse® DCA Interaction with Cabot PBX135® (3 plate cell scale study)
Flooded Cell Design: 3 Plate, 2V; 2 Positives, 1 Negative.
2:1 Ratio emphasizes the influence of the additive on the performance of negative electrode.
Expander Materials:
Control Cell: Test Groups:
Organic additive: Vanisperse® A Vanisperse® DCA
Organic dosage: 0.25% %, 0.20%, 0.40%, 0.60%, 0.68%
Carbon black: Acetylene type, ~ 75 m2/g Cabot PBX135®, ~150 m2/g
CB dosage: 0.1% %, 0.25%, 0.50%, 0.75%, 0.85%
BaSO4: 0.6% 0.6%
C20 = 8.5 Ah, I = 0.48 A, C1.5 (SAE) = 7.2 Ah, I = 4 A, 9C = 3.7 Ah, I = 60 A
Polypropylene separators
Grid: 10.8 cm x 14.2 cm x 1.1 mm (h x w x t)
5 Conditioning capacity tests.
2 SAE Capacity tests at C1.5.
SAE Static CA: Current, 10 min, 0oC
2 SAE Cold 18 oC, I = 60 A to 1.2 V (210 mA/cm2)
1 C20 capacity test
EN Cold oC, I = 50 A / 33 A to 1.0 V
qDCA
Capacity tests: C1.5, C20 and 9C.
PSoC cycle life: scaled per EN (E) protocols: 17.5% DoD at 50% SOC (without equalization)
Slide 12: Cell design Slide 20 Kuala Lumpur
Analysis of variance statistical treatment was used to determine experimental error, statistical significance, and define the performance-dosage relationship for each response and additive combination.
We used the flooded cell design, and performed the tests presented on this slide. The carbon black was Cabot’s PBX135. The organic expander was our Vanisperse DCA. .
2 V cell (2 pos. & 1 neg.)
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13. 4/9/2019
Results: Central composite response surface statistical computer model of 20 measurements.
0.75
0.25
0.75
0.25
0.75
0.25
-1.36
-1.42
-1.48
-1.36
-1.42
-1.48
Vanisperse DCA range: 0.12% to 0.68% Carbon range: 0.15% to 0.85%
Both, carbon and Vanisperse DCA, statistically influence the above responses.
As carbon content increases (higher carbon ratios): negative electrode depolarizes, charge acceptance improves, PSOC life improves.
As effective dosage increases: negative electrode polarizes, charge acceptance decreases, PSOC life decreases, C20 capacity decreases.
These findings are consistent of prior investigations.
Representative correlation plots and coefficients are presented at right.
Slide 13 Polarization end of discharge, C20 capacity, charge acceptance, PSOC Life
Each response model was generated using 20 data points from the testing nine combinations of Vanisperse DCA and Cabot’s BPX135 carbon.
The four contour plots present similar trends. A blue-to-red rainbow color gradient is used to designate progressively higher values from low-to-high.
Both, Vanisperse DCA and carbon influence each response. As carbon content increases, which is the y-axis, the negative electrode polarization decreases, while both charge acceptance and PSOC life improve.
As the Vanisperse DCA content increases, which is the X-axis, the negative electrode polarization increases, and charge acceptance, PSOC life and C20 capacity decrease. These findings are consistent with prior investigations.
To assist in explaining the performance-dosage models, we correlate results with two metrics: “Ratio-carbon-to-organic” and the “Effective-organic-expander-dosage”. All four shared strong correlations with these two metrics. Examples are presented at the lower right for the Negative Electrode Polarization.
Correlation coefficients:
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14. Results: Capacity Contour Graphs
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Results: Capacity Contour Graphs
0.75
0.25
0.75
0.25
0.75
0.25
Δ ~10%
Δ ~40%
Slide 14. C20, C1.5, 9C Capacity
The contour plots for the three capacity measurements are presented on this slide. Again, the blue-to-red color gradient represents the lowest to highest capacity values.
SLI batteries are designated by their C20 rating. The optimal capacity is at around 0.2% organic expander which explains why their organic expander dosage is in this region.
However, with the idle start/stop application, in the engine idle-off mode, the discharge rate is much greater than the C20 rate. It is in the C1 to C3 range. The contour plot for the C1.5 capacity suggests the negative electrode would gain 10% capacity with a slightly higher Vanisperse DCA dosage. To meet engine-off service loads, this additional capacity would be an advantage.
The benefit is greater for engine starting loads. In the 9C capacity test, a slightly greater dosage would boost the negative electrode’s performance 40%. This is an easy remedy to improve high rate performance to satisfy the VW Start/Stop test with the 300 amp discharge.
Capacity Rating: C20 C1.5 (SAE) 9C
Maximum Capacity (Ah):
Optimal Organic Expander Dosage (%): ~0.2% ~0.4% ~0.5%
Expander concentration has a strong effect on capacity
Negative electrode optimized for C20 rate capacity will perform sub-optimally when pressed into higher rate service
Unintended consequence of lost negative electrode capacity.

15. 4/9/2019
9C Capacity and EN Cold Crank Contour Responses: At high discharge rates, performance improves steadily until reaching an optimal at about 0.3% effective organic expander
0.75
0.25
4.0
1.5
4.0
1.5
Organic expander exerts a strong beneficial effect
Optimal regions perform substantially better than the low dosage region
Variance is best explained by ratio carbon to organic expander
Δ ~40%
0.75
0.25
200 60
200 60
Slide 15. 9C and EN CC Contour Plots
The EN cold crank and the 9C models are presented on this slide. At cold temperatures, the negative electrode’s high rate performance is boosted 60 to 90% with a slightly higher Vanisperse DCA dosage compared to the optimal C20 dosage.
Also noted in both Effective Organic Expander correlation plots, located at the right, is that high rate performance improves steadily reaching optimal at about 0.3%.
Δ ~60% - 90%
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16. Overlay Plot of Approximate Regions of Optimums
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Overlay Plot of Approximate Regions of Optimums
The optimal regions do not overlap
Depicts the impossible challenge engineers face to optimize all performance constraints simultaneously
To optimize overall performance, it may be necessary that some of the individual components function sub-optimally
EN Cold Crank
Slide 16. Overlay of Approximate Regions of Optimums
Not only must the negative electrode’s charge acceptance and PSOC life improve, but, to be truly useful, the negative electrode must also retain good cold start and capacity.
This overlay plot portrays the approximate optimal regions. It presents the challenge of selecting the best combination of carbon and organic expander. It is apparent the regions do not overlap. The best charge acceptance and PSOC life are found in regions of high carbon and low organic, while the best cold crank and high rate discharge are found in regions of low carbon and high organic expander.
So to optimize the negative electrode’s overall performance, it may be necessary that some of the individual components function sub-optimally.
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17. 4/9/2019
Optimization:
The yellow region defines combinations that meet the optimization criteria
– quite narrow – easy to miss –
Type I error – Benefit exists but we fail to detect it.
Bordered by cold crank criteria on it’s left side
And by charge acceptance and life it’s right side
Organic expander range: 0.3% to 0.38%
Carbon black range: 0.5% to 0.75%
Slide 17. Optimization Overlay plot based on EN criteria
With the computer model it is possible to conduct optimization scenarios and we use a control cell’s performance as a benchmark.
The yellow region defines the combinations that meet the optimization criteria listed at the bottom left. It runs roughly on a diagonal line, bordered between the optimization criteria for cold crank on its left side, and the optimization criteria for charge acceptance and life on it’s right side.
The lower left corner is at 0.3% organic expander and 0.5% carbon and the upper right corner is at 0.38% organic and 0.75 carbon.
Optimization – Based on EN test protocols:
- C20 cap.: 100% of control (8.6 Ah): 8.6 Ah
- EN CC: 85% of control (175 seconds): 150 seconds
- qDCA up: 120% of control (2.4 A): 2.9 A
- PSoC Life: 115% of control (558 cycles): 640 cycles
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18. Proof of Concept Investigation in Commercial 12 V Batteries
4/9/2019
Proof of Concept Investigation in Commercial 12 V Batteries
12 V flooded batteries manufactured by Superior Battery, Russell Springs, KY, USA
One factor design of Experiment: Organic expander – Replace Vanisperse A with Vanisperse DCA
Vanisperse DCA at 0.25% and 0.30% (Effective organic dosage: ~ 0.25% and ~ 0.29%)
Vanisperse A at 0.30% (Effective organic dosage: ~ 0.29%
Traditional carbon black, 75 m2/g: 0.1%
Barium sulfate: %
12 V Group 65 Flooded Battery (~LN4)
Slide 18. Proof of Concept Investigation in Commercial 12 V Batteries.
To demonstrate the benefits of Vanisperse DCA’s improved charge acceptance and PSOC life, a proof of concept investigation was performed with 12 V flooded SLI batteries manufactured by Superior Batteries. Vanisperse A was replaced by Vanisperse DCA at 0.25% and 0.3%.
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19. Charge Acceptance, Capacity, Cold Crank
4/9/2019
Charge Acceptance, Capacity, Cold Crank
Significant improvement in charge acceptance and capacity.
Cold crank performance nicely improved at 0.3% dosage.
Mixed results at the lower 0.25%, not surprisingly given the known dosage response.
Slide 19. Charge Acceptance, Capacity, Cold Crank – 12 V Batteries
These results complement findings presented earlier using 2 V cells. Charge acceptance, capacity and cold crank are all improved. Charge acceptance was up 7 to 8%, capacity was up 5 to 7% and cold crank improved for the 0.3% dosage by 5 and 19%.
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20. 4/9/2019
Life Test Results
PSOC Life: 17.5% DoD at 50% SoC
PSOC life improved from:
9.8 units for Vanisperse 0.3% to
12.8 units for Vanisperse 0.3% (31%)
12.9 units for Vanisperse 0.25% (32%)
PSOC life improved from:
10.5 units for Vanisperse 0.3% to
11.7 units for Vanisperse 0.3% (11%)
12.2 units for Vanisperse 0.25% (16%)
High temperature life maintained or improved from:
10.0 units for Vanisperse 0.3% to
10.8 units for Vanisperse 0.3% (8%)
10.2 units for Vanisperse 0.25% (2%)
Slide 20. Life Test Results
The graphs indicate significant improvement was achieved in both PSOC life tests. Batteries containing Vanisperse DCA posted a 30% improvement in the VW 17.5% DoD test. Which is the left figure.
And in the difficult VW Start/Stop test, Vanisperse DCA batteries posted substantial 11% and 16% improvements, which is the center figure. So evidently, the improved charge acceptance did transfer to improved PSOC life performance.
The SEA J2801 results are presented in the right figure and indicate Vanisperse DCA batteries posted 8% and 2% improvements. This is significant since reportedly some EFBs experience shortened life on this high temperature test.
The improved charge acceptance did transfer to improved PSOC life performance.
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21. Life Tests: Water Consumption
4/9/2019
Life Tests: Water Consumption
Water Consumption
17.5% DoD
g/cycle
VW Start/Stop
Test, g/wk
SAE J2801
Weight Change,
g/wk VW
Overcharge
at CV Test,
g/Ah
Vanisperse 0.30% 44 72 80
2.4
Vanisperse 0.30% 63 78
2.5
Vanisperse 0.25% 42 60 75
2.1
Relative to
Vanisperse A
Weight Change
Test Water
Consumption
at CV Test
100%
99%
88%
97%
108%
94%
84%
90%
Slide 21. Life Tests: Water Consumption
Results were also favorable for reducing water consumption. In the VW 17.5% DoD test, weight change was reduced by 1 and 4%. While for the VW Start/Stop test, water consumption was reduced 12 and 16%. In the high temperature SAE 2801 life test, 3% and 6% reductions in water loss were reported.
In the VW Overcharge Test, the test groups performed very well. They were easily below the imposed 3 g/Ah threshold and indicate this manufacturer has excellent control over water loss.
Significant reduction in water loss for the three life tests.
Effective control of water loss on the VW Overcharge test.
All three groups were well below the 3 g/Ah requirement.
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22. Superior Batteries Prototype EFB: VW Start/Stop Test
4/9/2019
Superior Battery, Russell Springs, KY, USA
Group 65 ~ LN4
Vanisperse 0.3% effective dosage
Proprietary additives in negative and positive electrodes.
Proprietary cell architecture.
VW Start/Stop Results:
All four batteries have passed 21 units!
Exceeded start/stop requirement of 14 units.
Presented with permission by Superior Battery
Slide 22. VW Start/Stop Test with Prototype EFB
With these promising results, Superior Battery incorporated Vanisperse DCA into their EFB at an effective dosage of 0.3% along with other proprietary improvements. All Vanisperse DCA batteries easily exceeded the 14 unit requirement, and as indicated, all four passed 21 units. The last we heard, they completed 31 units.
This is certainly good news for Superior Batteries! And also for the industry as a whole since it demonstrates EFBs can convincingly meet and exceed the VW Start/Stop requirements which up to recently had been a very challenging obstacle.
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23. Credits/Acknowledgements
4/9/2019
Credits/Acknowledgements
Borregaard LignoTech for supporting and financing the research
Colleagues: Dr. Jeffrey Poirier
Samuel Shafarik
Slide 23 Credits
This concludes my presentation. I hope you found it helpful. I’d like to thank Borregaard LignoTech for financing this research and also my colleagues Dr. Jeffrey Poirier and Sam Shafarik.
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