Due date of deliverable: 31/05/2017 Actual submission date: 20/05/2017 Organisation name of lead contractor for this deliverable: CEA

Transcription

1 Project number: Deliverable report Deliverable No.: D5.4 CEA reference: DEHT/LV/2017/046 P Deliverable title: Technical-Economic assessment of final Catalyst/Support/MEA concept Due date of deliverable: 31/05/2017 Actual submission date: 20/05/2017 Organisation name of lead contractor for this deliverable: CEA

2 1 OBJECTIVES The objectives of the task 5.4 are to provide an estimate of manufacturing cost of the MEA developed within the project and to compare it with the prior art. 2 CHARACTERISTICS OF DEVELOPPED MEA AND PRIOR ART The MEA developed within the project and selected for the cost assessment is the one with Pt 2AuNi cathode catalyst, coated by PVD process. It will be compared with the reference assessed in the AUTOSTACK Core FCH-JU project. The characteristics measured in the experimental tasks (WP ) of the project on small stack at CEA are summarized in the following table. name Catalyst loading Small stack test CEA MEA Cathode Anode Max Power density MEA smartcat Table 1: Description and experimental results on MEA selected for cost assessment 3 METHODOLOGY Pt2AuNi Pt 50 µg/cm 2 Au µg/cm 2 Ni 8.39 µg/cm Cost model presentation Pt Pt 50 µg/cm V at 0.4 A/cm W/cm 2 CEA developed a detailed cost model of PEM fuel cell MEA and stack, improved through different FCH JU projects like IMPALA, IMPACT, and MATISSE. It enables to calculate the manufacturing cost taking into account the specific MEA design, different fabrication methods, production rate limitations, material selections and components at different production scale. Actually, this detailed model involves hundreds of input data. The figure below proposes a schematic illustration of the cost model. Figure 1: Schematic representation of PEMFC Cost Model

3 3.2. General hypothesis and application case of the cost assessment The SmartCAT MEA will be assessment considering an automotive application. The manufacturing scale will be 50,000 stacks of 95 kw gross per year. The size of the MEA will be similar to the Autostack Core reference with an active area of 300 cm 2. The manufacturing plant will be based in France, and will operate at a shift of 5x8. The MEA performance will define the required manufacturing scale to provide 50,000 automotive stacks of 95 kw gross per year: MEA ref System gross electric power (kw) 95 System net electric power (kw) 80 Cathodic catalyst loading (µg/cm 2 ) 300 (Pt) MEA SmartCAT 50(Pt), 25.18(Au), 8.4(Ni) Anodic catalyst loading (µg/cm 2 ) 50 (Pt) 50 (Pt) Power density (W/cm 2 ) Active area per cell (cm 2 ) Number cells per system 317 2,258 Manufacturing scale : system unit/yr. 50,000 Number of MEAs per year 15,850, ,900,000 Table 2: Operational and design parameters of the assessed MEAs Due to its low performance, the number of required SmartCAT MEA is unrealistic. Nevertheless, the assessment will be pursued, and an analysis with a MEA performance of 1 W/cm 2 will be provided at the end. 4 MANUFACTURING AND RAW MATERIALS ASSESSMENTS 4.1. Manufacturing process: focus on cathode coating This study will focus on cathode side coating GDL process steps. The other parts of the MEA manufacturing will be considered unchanged compared to the reference. In prior art, the cathode coating is realized on the membrane (CCM catalyst Coated Membrane) or on the GDL (GDE). The operation consists in preparing a catalyst ink (mixed and extruded) and deposing on the surface thanks to a slot-die coater in reel-to-reel processing with an IR or convective drying oven. Deposition can also be done by screen printing using a roll-to-roll processing (like it is done in the pre-industrial line at CEA). The next steps are the MEA assembly : in the case of GDE, both anode and cathode active layers previously coated on the GDL are assembled with the membrane by hot pressing with sealing frames in polyester or polyethylene to bring rigidity. Following, a punch step makes the manifolds and define the final MEA size. SmartCAT project developed another process to coat thinner catalyst layer thanks to a sputtering magnetron technology. Development and first production was done at laboratory scale at CNRS Orléans.

4 In the techno-economic approach, the laboratory process is studied to be transferred to mass production. Thanks to PVD tool supplier s feedback the throughput and main technical and economic characteristics of such a process were established. PVD tool using load-lock loading and parallel PVD processing in small coating chambers is chosen in order to achieve very short cycle times and small batch allowing integration of PVD in lean-organized volume production. The following table describes the technical and economic data of the process tools for the catalyst coating steps, used in the model for MEA production cost assessment. Process Tool SLOT-DIE COATER Iine REFERENCE SLOT-DIE-COATER line Reel-to-reel processing with rewinder/unwinder systems, slotdie coater, IR drying oven, marking, control speed rate 360 electrodes/hr. 240 electrodes/hr. installed power 40 kw 50 kw tool footprint 10 m 2 20 m 2 maintenance rate 10% 10% tooling, consumables manpower/tool/op. hr 1 operator 1 operator capital investment 520 k k DISSOLVER speed rate installed power Preparation of catalyst ink for electrodes Dispermat dissolver solution tool L/h 2.2 kw tool footprint 0.5 m 2 maintenance rate 3% manpower/tool/op. hr capital investment 15 k BLENDER capacity installed power operator tri-dimensional blender 50/100 L 0.6 kw tool footprint 1 m 2 maintenance rate 3% manpower/tool/op. hr operator capital investment 89 k Table 3: Slot-die coating and Magnetron sputtering process data SMARTCAT MAGNETRON SPUTTERING Load-lock loading and parallel PVD processing in 3 small coating chambers Kit of 192 /kit replaced each day

5 4.2. Raw materials: focus on cathode catalyst Platinum is a key cost factor in the overall cost of the fuel cell stack. Most of the time in MEA cost assessment, platinum catalyst cost is linked to Pt spot market price and additional components, manufacturing and markup are neglected. The spot market price of Pt is subject to large fluctuations as illustrated by the figure. Thus, the estimated Pt price should be made carefully. From 2008 to 2013, the cost analysis funded by the DoE assumed a price of $1,100 per troy ounce. From the 2013 update report released by Strategic Analysis Inc for the DoE, the value was increased to $1,500 per troy Figure 2: Platinum price in the spot market for the last ten years (source: metalprices.com) ounce to correspond to the new plateau price. Since middle of 2014, the platinum price keeps on going down and it seems to settle around $ 1,000 per troy ounce. Generally, the price of Platinum is held constant in the cost analysis to insulate the system cost analysis from arbitrary market price fluctuations. Furthermore, another parameter has to be taken into account: the Euro to US dollar exchange rate. Indeed, since end of 2014, the EUR/USD exchange rate has felt from 1.3 to below 1.1, compensating in some way the metal price decrease when converted in euro currency Platinum catalyst ink cost for the MEA of reference For conventional coating process, raw materials are the catalyst platinum in powder, dispersing solvent and ionomer. According to the available cost studies, there can be different way to fix catalyst Platinum price. The spot market price can be directly used without any markup like in [DoE-SAI_13], it can come from quotation like [BERKELEY_14], or include a variable margin depending on volume purchased like CEA model. This last approach was validated by catalyst suppliers, who reviewed the markup to be considered according to annual purchased volume. Since the markup includes, in part, the manufacturing cost of the catalyst which is independent of the Pt Spot price, the Pt spot price was fixed to a current average value of $1,000 per tr.oz corresponding to the new plateau price and EUR/USD at 1,08. source Platinum catalyst price CEA model spot market base price and variable margin applied to this value depending on purchased quantity: Annual quantity 5 kg Pt/yr 50 kg Pt/yr 500 kg Pt/yr 5 t Pt/yr Price according to quantity spot market price (~$1,000 per tr.oz) + 70% markup spot market price (~$1,000 per tr.oz) + 50% markup sport market price (~$1,000 per tr.oz) + 35% markup spot market price (~$1,000 per tr.oz) + 25% markup Table 4: Platinum catalyst price calculated for different volume purchased The following figure illustrates the Pt catalyst price according to quantity purchased. The learning curve relates the specific price of Pt catalyst (in /grpt) to the annual purchased quantity (in kg Pt/yr.).

6 Figure 3: Pt catalyst price versus quantity of Pt purchased and learning curve Nota: concerning ionomers and solvent, they were quoted by suppliers for different purchased volumes and learning curve formulas were deducted. Ionomer: Y( kg) = LN(x 5 ) LN(2) Trimetallic target cost for the SmartCAT MEA Concerning the SmartCAT MEA cathode coated by PVD processing, raw materials consist in targets made with the corresponding metals. With its trimetallic catalyst Pt 2AuNi, they can be 3 targets of pure metal or a single target with the required metals composition. In the PVD processing, only a small part of the target is directly used for coating. This represents usually 15% of the target and the remaining part is recycled and used again. Then, except at the beginning, when a new target has to be bought, the following times, the cost of Pt 2AuNi coating has to take into account the target recycling cost, covering the processes to recycle the remaining metals and to make a new target as well as the cost of Pt, Au, Ni materials required to compensate the part used or lost in the process. Then, the cost of Pt 2AuNi coating in /MEA can be calculated by the following formula: W 0 (kg) W r (kg) (1 % recycl.loss ) P Pt,Au,Ni Spot ( gr) C recycl.proc. ( target) C Pt2AuNi ( MEA) = Q MEAs/target W 0 initial target weight W r end of life target weight and Au waste to recycle % recycl. loss Percentage loss in recycle process P Pt,Au Spot Platinum, Gold, Nickel Market spot prices with a supplement 5% for trade target cost of the recycle process C recycl.proc.

7 REF: Au Magnetron sputtering Raw material Specifications Material: Pt2AuNi Shape: target Weight: 29.3 kg Quantity/MEA Cathode side Pt 50 µg/cm 2 Au 25 µg/cm 2 Ni 8.4 µg/cm 2 MEA units /target End of life target weight (before recycling) 83 %w (/initial target weight) 17 %w of the target used for coating: ~1.6 M MEAs /target Table 5: Input data for the calculation of raw materials cost in PVD coating Raw materials cost Average spot market : Pt: /gr Au: 37,30 /gr Ni: /gr +5% supplement for trade Recycling 83%w of the target is recycled Loss in recycling process : 0.8% Cost of recycling : 65 k /target Raw materials cost depends on the spot market prices. The figures below present the market price of Platinum, Gold and Nickel in 2016 and It can be noticed that during this period of time, the profile for Au and Pt is very similar with a fluctuation of ±15% around the average. However, Gold is more expensive than Platinum, then from an economic point of view, it does not seem relevant to replace the platinum load of PEMFC by Gold unless it enables to reduce catalyst quantities. Figure 4: Platinum, Gold, Nickel prices in the spot market for the last ten years (source: metalprices.com)

8 5 RESULTS OF COST ASSESSMENT The following chapters present the results of the cost model for both SmartCAT and Reference MEAs calculated considering a production scale of 50,000 stacks of 95 kw gross. Values are expressed in per surface unit and in per kw, in order to outline the difference when considering the performance and partly not. Actually, even expressed in /m 2, the results are not completely independent of the performance. In the cost model, the production scale was fixed to 50,000 automotive stacks per year and the corresponding number of MEAs was calculated taking into account the performance and power density. Then because a larger number of MEAs was produced in the case of SmartCat, raw materials components benefit from a higher volume effect on the price MEAs production results The following figures present the MEAs manufacturing cost, and the financial shares of raw materials and process in /m 2 active area and in /kw gross: Figure 5: MEAs SmartCAT and Reference manufacturing cost expressed in /m 2 of active area and /kw The low catalyst load of MEA SmartCAT enables to halve the cost in /m 2 of the state of the art MEA. However, when considering the performance, since the SmartCAT MEA did not reach the target of 1 W.cm 2 (only 15% of the target), the result in /kw is 3.7 times more expensive than the reference and this would be far higher when considering the stack (additional bipolar plates for instance). It is worth noting that raw materials share represents around 85% of the MEA manufacturing cost MEAs raw materials cost breakdown The following figures present the financial shares of raw materials MEA in /m 2 active area and in /kw gross:

9 Figure 6: MEAs SmartCAT and Reference raw materials cost breakdown That is the low catalyst load of SmartCAT MEA that enables to halve the cost in /m 2 of the state of the art MEA. For SmartCAT MEA, the electrode catalysts share represents half the total cost of raw material. Nota: It could be expected that the GDL and Electrolyte shares expressed in /m 2 would be similar for SmartCat and Reference MEAs. However, because of the larger volume of production for SmartCAT MEA these components benefit from a higher volume effect on the price MEAs process cost breakdown The following figures present the financial shares of processing MEA in /m 2 active area and in /kw gross Figure 7: MEAs SmartCAT and Reference process cost breakdown The SmartCAT process cost breakdown shows that at the same production scale, the Cathode PVD deposition, is more expensive by 2.5 than the Anode ink deposition. Since the process cost is almost negligible in the MEA manufacturing cost compared to raw materials share at large production scale, this higher cost has a low impact Results if SmartCAT MEA at the target of 1 W/cm 2

10 The following figure presents the result if the SmartCAT MEA would have achieved the performance target of 1 W/cm 2. Then, the SmartCAT MEA produced at the same production scale as the Reference (50,000 automotive stacks per year), would have been 30% cheaper. Despite a cathode PVD coating process 2.5 times more expensive than the ink deposition, SmartCAT MEA remains cheaper, thanks to its low load trimetallic catalyst with Pt at 50 µg/cm 2 and Au at 25 µg/cm 2 compared to the cathode of the Reference MEA at 0.3 mg/cm 2 Pt. Figure 8: MEAs manufacturing cost with SmartCAT at 1 W/cm 2

11 6 CONCLUSIONS This report establishes the manufacturing cost of SmartCAT MEA, considering that the process developed in laboratory within the project was transferred to industry. The value obtained was compared to the state-of-the art reference from Autostack Core project: MEA with platinum loading 3.5 mg/cm 2 and 0.93 W/cm 2. Due to its low performance, the SmartCAT MEA could not compete against the Reference. Nevertheless, the techno-economic analysis demonstrates the high potential of this coating technology. It was found that some industrial PVD tools are designed already to easily integrate a continuous manufacturing line. Despite a process cost estimated to 2.6 times more expensive than the conventional ink deposition, the cost assessment shows that it could became negligible at high production rate. Concerning the choice of the trimetallic catalyst Pt 2AuNi, from an economic point of view, it does not seem relevant to replace the platinum load of PEMFC by Gold, more expensive, unless it enables to reduce catalyst quantities. If the SmartCAT MEA would have reached the performance target of 1 W/cm 2, it would have reduced the MEA cost by 30% and dropped below 20 /kw gross (production scale: 50,000 automotive stacks of 95 kw gross).