LABAT 17 Golden Sands CARBON S IMPACT ON ACTIVE MATERIAL UTILIZATION IN ADVANCED LEAD-ACID BATTERIES USING THIN PLATE TECHNOLOGY Jérémy Lannelongue PhD Engineering researcher (with A. Kirchev & M. Cugnet)
INTRODUCTION Specific energy density [Wh/kg] Volumetric energy density [Wh/L] Advantages Low cost Safety Recycling Current limitations Charge acceptance/ Power Structure and thickness of grids Energy density Weight / Pb utilization : 3 to 6 % (4 % typical) Lifetime Active material degradation Corrosion of current collectors LABAT 17, 13-16 June, Golden Sands, Bulgaria Jérémy Lannelongue 2
INTRODUCTION Thin-plate lead-acid and lead-carbon battery design Benefits Lower current density lower polarization Thinner separators lower ohmic drop Faster diffusion high rate performance Spiral-cell design enhanced compression Pending issues o Positive grid corrosion o Faster degradation of PAM o Growth of dendrites o NAM sulfation (HRPSoC) Examples Thin-plate prismatic and spirally wound AGM-VRLAB using pasted grids (plate thickness ~.8-1 mm) Boulder TMF technology*: double-side coated lead foils (plate thickness ~.25 mm) * R.C. Bhardwaj, J. Than, Lead acid battery with thin metal film (TMF ) technology for high power applications, J Power Sources 91 (2) 51-61 LABAT 17, 13-16 June, Golden Sands, Bulgaria Jérémy Lannelongue 3
ALTERNATIVE CURRENT COLLECTORS FOR THIN PLATE AGM-VRLAB The approach of CEA-Liten: diversified selection of corrosion-resistant materials Positive current collectors Expanded Ti mesh or foil Thickness ~ 2-1µm DSA type of surface treatment SnO 2 interlayer Optional galvanic PbO 2 layer Negative current collectors Flexible carbon support (copper can be an alternative) Thickness ~ 4-2µm Lead electroplating ~ 1-3µm Tunable electric conductivity.5 mm.5 mm Expanded Ti mesh samples from Dexmet corporation Graphite foil (ex. Papyex Mersen) Carbon fabric Carbon paper (ex. Tenax, Toho Tenax) (ex. Toray TGP-H-6) LABAT 17, 13-16 June, Golden Sands, Bulgaria Jérémy Lannelongue 4
THIN-PLATE ELECTRODES PREPARATION Lab version: one side coating Coating of pasting paper using a film applicator The conventional pasting is replaced by a coating process, which is more appropriate for application of Paste mixing: ULTRA TURRAX Tube Drive with glass beads thinner paste layers Process scale-up: Roll-to-Roll double side coating* Nominal capacity:,1,5 Ah * A.Kirchev and M. Perrin, Patent application WO21518158 (A1) 215-12-3 LABAT 17, 13-16 June, Golden Sands, Bulgaria Jérémy Lannelongue 5
STRUCTURE OF THE THIN-PLATE ELECTRODES Pb coating Graphite foil Negative paste (~ 45 µm) Electroplated PbO 2 Ti mesh Positive paste (~ 4 µm) Positive paste Titanium PbO 2 Negative paste types Negative plate 3BS paste with.2 % Vanisperse A and 2 % MCF AC + 3BS: hybrid paste SnO 2 Positive plate Positive paste: 3BS LABAT 17, 13-16 June, Golden Sands, Bulgaria Jérémy Lannelongue 6
CELLS WITH 3BS «CLASSIC» PASTE Best active material utilization (AMU) [%] 1 8 AM nominal capacity [mah] Set 1 NAM ~ 13 µm 6 42 352 393 22 33 357 192 4 2 5 x 5,5 cm² C1 C2 C3 C5 C6 C7 C8 Three electrode cells Negative paste : 3BS + VsA + MCF AGM separator Ag/Ag 2 SO 4 reference electrode PAM NAM Lead maximal utilization : 62 % negative electrode cross section after 2 deep-discharge cycles negative : NAM crushing Flexible PE casing with external compression of the active block Charge management : constant activated carbon doping current / constant voltage (2.45 V) Charge factor 1,15 LABAT 17, 13-16 June, Golden Sands, Bulgaria Jérémy Lannelongue 7
CELLS WITH 3BS + AC «HYBRID» PASTE Carbon part composition: 85 % activated carbon YP-5F (Kuraray Chemical) 5 % carbon black SC2 (Cabot Corporation) 5 % milled carbon fibre (Toho Tenax) 5 % binder (CMC) Lead part: 3BS +.2 % Vanisperse A 1 8 6 4 2 Best NAM utilization [%] vs Mass ratio PbO:C NAM nominal capacity [mah] Set 1 239 189 147 236 221 194 192 16 163 46,6:1 2,5:1 5:1 1:1 18:1 2:1 22:1 25:1 3:1 2: High carbon content inhibits the discharge reaction. 1 %wt carbon content: visible boost effect 2:1 mass ratio (5 %wt): best utilization best retention 3 18:1 2:1 3 3 22:1 25:1 3:1 3 3 25 25 25 25 25 C s [mah/g Pb ] 2 15 1 5 2 15 1 5 2 15 1 5 2 15 1 5 2 15 1 5 - - - C s (Pb) = 258,7 Ah/g C/2 rate C/1 rate C/5 rate 5 1 15 5 1 15 5 1 15 5 1 15 5 1 15 LABAT 17, 13-16 June, Golden Sands, Bulgaria Jérémy Lannelongue 8
CELLS WITH 3BS + AC «HYBRID» PASTE : DEEP-DISCHARGE CYCLING Mass ratio PbO:C = 2:1 C s [mah/g Pb ] 3 25 2 15 1 5 Thickness influence on specific capacity theoretical Cs(Pb) = 258,7 mah/g Pb 78 85 239 418 454 NAM nominal capacity C nom NAM [mah] NAM utilization [%] 1 8 6 4 2 Utilization vs. Deep-discharge cycles 2 4 6 8 1 12 14 Optimal mass ratio Better utilization with thin NAM retention of the utilization : 47 % after 126 cycles (probably more without short-circuit at cycle 127) LABAT 17, 13-16 June, Golden Sands, Bulgaria Jérémy Lannelongue 9
CELLS WITH 3BS + AC «HYBRID» PASTE : DEEP-DISCHARGE CYCLING Cell with AC vs. cell without AC NAM utilization [%] 1 8 6 4 2 Utilization vs. Deep-discharge cycles with AC 2 4 6 8 1 12 NAM utilization [%] 1 8 6 4 2 Utilization vs. Deep-discharge cycles 2 4 4 6 6 8 8 1 1 12 12 without AC Better utilization with active carbon Better retention of the utilization : 47 % after 126 cycles with AC / 47 % after 48 cycles without AC LABAT 17, 13-16 June, Golden Sands, Bulgaria Jérémy Lannelongue 1
CELLS WITH 3BS + AC «HYBRID» PASTE : HRPSOC CYCLING 1 Mass ratio PbO:C = 2:1 UMA [%] Cell with C nom NAM = 78 mah/g Pb 1 8 6 4 2 1 2 3 4 Time [min] Peukert line 1 log(t) = -1,397*log(I)+4,4593 1 1 1 t disch = 12 min I disch = 269 ma 1 1 1 1 I [ma] High-Rate Partial State of Charge cycling 1, step 1: characterization Deep-discharge cycles with various rate (from.5c to 5C) Computation of the actual current corresponding to 5C rate, using Peukert plots LABAT 17, 13-16 June, Golden Sands, Bulgaria Jérémy Lannelongue 11
CELLS WITH 3BS + AC «HYBRID» PASTE : HRPSOC CYCLING 1 Mass ratio PbO:C = 2:1 SOC SOC = 1 % / I (5C 12min ) 3 2,5 HRPSoC1: cycle 756 25 2 8 % 2 15 HRPSoC 1 t dsch = 72 s t ch = 72.36 s t ocv = 2 s Faradic efficiency = 99.5 % 1 µ-cycles correspond to one equivalent cycle time Voltage [V] 1,5 1,5 1 5-5 5 1 15 2 Time [s] I [ma] Ucell Upos -Uneg Current Negative electrode: good charge acceptance o o Negative electrode: H 2 gassing Positive electrode: fast but stable polarization LABAT 17, 13-16 June, Golden Sands, Bulgaria Jérémy Lannelongue 12
CELLS WITH 3BS + AC «HYBRID» PASTE : HRPSOC CYCLING 1 Mass ratio PbO:C = 2:1 1 year of HRPSoC at 5C rate Stability over the cycling Reversible sulfation Energy efficiency between 8-82 % 88 5 HRPSoC cycles = 8 85 equivalent cycles Max HRPSoC cycles/set : 18 64 = 1 864 eq. cycles Check-up : 68 % utilization after 8 9 eq. cycles µ LABAT 17, 13-16 June, Golden Sands, Bulgaria Jérémy Lannelongue 13
CELLS WITH 3BS + AC «HYBRID» PASTE : HRPSOC CYCLING 2 Mass ratio PbO:C = 2:1 UMA [%] 1 8 6 4 2 Cell with C nom NAM = 239 mah/g Pb 1 2 3 4 Time [min] Peukert line 1 log(t) = -1,2946*log(I)+4,7423 1 1 1 t disch = 3 min I disch = 333 ma 1 1 1 1 I [ma] High-Rate Partial State of Charge cycling 2, step 1: characterization Deep-discharge cycles with various rate (from.5c to 5C) Computation of the actual current corresponding to 2C rate, using Peukert plots LABAT 17, 13-16 June, Golden Sands, Bulgaria Jérémy Lannelongue 14
CELLS WITH 3BS + AC «HYBRID» PASTE : HRPSOC CYCLING 2 Mass ratio PbO:C = 2:1 HRPSoC cycling 2: cycle 9724 HRPSoC cycling 2 : cycles 19948 & 19949 SOC SOC = 6,7 % / I (2C) & I (1C) 3 25 66,7 % HRPSoC 2: standard IEC 61427-2 Voltage [V] 2,5 2 1,5 1 2 15 1 5 I [ma] Faradic efficiency = 99 % 7,5 µ-cycles correspond to one equivalent cycle time,5-5 2 4 6 8 Time [s] Ucell Upos -Uneg Current Negative electrode: good charge acceptance o o Negative electrode: H 2 gassing (2C step) Positive electrode: fast polarization LABAT 17, 13-16 June, Golden Sands, Bulgaria Jérémy Lannelongue 15
CELLS WITH 3BS + AC «HYBRID» PASTE : HRPSOC CYCLING 2 Mass ratio PbO:C = 2:1 3,5 Voltage and efficiency evolution during HRPSoC cycling 2 1 4 month of HRPSoC test at 1C/2C rate Voltage [V] 3, 8 2,5 6 2, 4 1,5 2 1, 5 1 15 2 25 3 35 4 Equivalent cycle (@1 % DoD) Max voltage (charge) Min voltage (discharge) Energy Efficiency Energy efficiency [%] First 1 cycles : stability over the cycling Reversible sulfation Average energy efficiency: 85 % 26 2 HRPSoC cycles = 1 746 equivalent cycles Check-up: 47 % NAM utilization after 1 13 eq. cycles Max HRPSoC cycles/set: 9 7 = 645 eq. cycles X Problem : Positive became the limiting electrode LABAT 17, 13-16 June, Golden Sands, Bulgaria Jérémy Lannelongue 16
CELLS WITH 3BS + AC «HYBRID» PASTE : HRPSOC CYCLING 2 Mass ratio PbO:C = 3:1 3,5 Voltage and efficiency evolution during HRPSoC cycling 2 1 5 month of HRPSoC test (still cycling) at 1C/2C rate Voltage [V] 3, 8 2,5 6 2, 4 1,5 2 1, 5 1 15 2 25 3 35 4 Equivalent cycle (@1 % DoD) Max voltage (charge) Min voltage (discharge) Energy efficiency Energy efficiency [%] Stability over the cycling Reversible sulfation Average energy efficiency : 87 % 46 2 cycles = 3 8 equivalent cycles Max HRPSoC cycles/set: 26 8 = 1 787 eq. cycles (still running) Check-up: 33 % utilization after 1 29 eq. cycles LABAT 17, 13-16 June, Golden Sands, Bulgaria Jérémy Lannelongue 17
COMPARISON WITH EXISTING TECHNOLOGIES Titaflex prototype Maximum deep-discharge cycles Maximum HRPSoC1 cycles/set Cumulative number of HRPSoC1 cycles Maximum HRPSoC2 cycles/set (running) Cumulative number of HRPSoC2 cycles (running) * Garche J, Karden E, Moseley P, et. al. Lead-Acid Batteries for Future Automobiles, Elsevier (217) 166 LABAT 17, 13-16 June, Golden Sands, Bulgaria Jérémy Lannelongue 18
INFLUENCE OF VANISPERSE A, AC AND THICKNESS Utilization @ 1 % DoD NAM utilization [%] 1 8 6 4 2 without AC,2 %m Vs-A C NOM = 352 mah 5 1 15 NAM utilization [%] 1 8 6 4 2 with AC (2:1),2 %m Vs-A C NOM = 78 mah 5 1 15 NAM utilization [%] 1 8 6 4 2 with AC (2:1),6 %m Vs-A C NOM = 418 mah 5 1 15 2 25 3 Utilization can be raised by : Adding activated carbon Using thin paste layer Activated Carbon adsorbs Vs-A, limiting the retention Increase the Vs-A content enhances the capacity retention LABAT 17, 13-16 June, Golden Sands, Bulgaria Jérémy Lannelongue 19
CONCLUSIONS & PERSPECTIVES Laboratory demonstration of new thin-plate technology concept suitable for lead-based batteries with different types of negative active materials Affordable and commercially available current collector substrates based on abundant chemical elements (C and Ti) Rapid and cost-efficient electrode preparation stages which can be scaled-up in Roll-to-Roll processing installations Study of the lead-carbon electrochemistry in thin-plate negative electrodes At high carbon fraction, NAM utilization is limited (partial inhibition of the Pb dissolution), while the charge acceptance (the reaction PbSO 4 Pb) in HRPSOC cycling mode remains high A decrease of the carbon content exerts a boost effect on the Pb/PbSO 4 electrode The utilization of the lead at low discharge rates exceeds 88 % Good retention of the capacity in both deep-discharge and HRPSoC cycling The energy efficiency ~ 85% indicates good charge acceptance This design could be tuned for both deep cycling and high rate partial state of charge cycling applications LABAT 17, 13-16 June, Golden Sands, Bulgaria Jérémy Lannelongue 2
ACKNOWLEDGEMENTS The team of CEA-LSEC would like to express its sincere gratitude to the companies who provided free of charge the materials and the components used in the development of the cells Expanders Carbon black Titanium mesh AGM separators Activated carbon Milled carbon fibers the financial support provided by the French National Environmental and Energy Agency (ADEME) S. BISCAGLIA (ADEME referent), A. KIRCHEV (director) and M. CUGNET (advisor) LABAT 17, 13-16 June, Golden Sands, Bulgaria Jérémy Lannelongue 21
THANKS FOR YOUR ATTENTION Jérémy LANNELONGUE PhD Engineering researcher T. +33 ()4 79 79 2 66 Email 1: jeremy.lannelongue@cea.fr Email 2: jeremy.lannelongue@orange.fr Institut National de l Energie Solaire National Solar Energy Institute 5 avenue du lac Léman 73375 Le Bourget-du-Lac France +33 4 79 79 2 Public Industrial and Commercial Establishment RCS Paris B 775 685 19