Performance Studies of Proton Exchange Membrane Fuel Cells with Different Flow Field Designs – Review

Proton Exchange Membrane Fuel Cell (PEMFC) is majorly used for power generation without producing any emission. In PEMFC, the water generated in the cathode heavily affects the performance of fuel cell which needs better water management. The flow channel designs, dimensions, shape and size of the rib/channel, effective area of the flow channel and material properties are considered for better water management and performance enhancement of the PEMFC in addition to the inlet reactant's mass flow rate, flow directions, relative humidity, pressure and temperature. With the purpose of increasing the output energy of the fuel cell, many flow field designs are being developed continuously. In this paper, the performance of various conventional, modified, hybrid and new flow field designs of the PEMFC is studied in detail. Further the effects of channel tapering, channel bending, landing to channels width ratios, channel cross-sections and insertion of baffles/blockages/pin-fins/inserts are reviewed. The power density of the flow field designs, the physical parameters like active area, dimensions of channel/rib, number of channels; and the operating parameters like temperature and pressure are also tabulated

Performance Studies of Proton Exchange Membrane Fuel Cells with Different Flow Field Designs – Review

Proton Exchange Membrane Fuel Cell (PEMFC) is majorly used for power generation without producing any emission. In PEMFC, the water generated in the cathode heavily affects the performance of fuel cell which needs better water management. The flow channel designs, dimensions, shape and size of the rib/channel, effective area of the flow channel and material properties are considered for better water management and performance enhancement of the PEMFC in addition to the inlet reactant's mass flow rate, flow directions, relative humidity, pressure and temperature. With the purpose of increasing the output energy of the fuel cell, many flow field designs are being developed continuously. In this paper, the performance of various conventional, modified, hybrid and new flow field designs of the PEMFC is studied in detail. Further the effects of channel tapering, channel bending, landing to channels width ratios, channel cross-sections and insertion of baffles/blockages/pin-fins/inserts are reviewed. The power density of the flow field designs, the physical parameters like active area, dimensions of channel/rib, number of channels; and the operating parameters like temperature and pressure are also tabulated

Electrodeposition of vanadium pentoxide on carbon fiber cloth as a binder-free electrode for high-performance asymmetric supercapacitor

Electrodeposition technique is a convenient and robust approach for the development of transition metal oxides as electrodes, particularly for supercapacitor applications. However, achieving uniform coating is difficult and relies on the constrained deposition parameters. Herein, we fabricated the binder-free spiral rope-like structured V2O5 on carbon fiber cloth (CFC) by simple and versatile electrodeposition method for high performance asymmetric supercapacitors. The deposition rate of V2O5 nanostructures on CFC was controlled by varying the electrodeposition duration. The resultant optimum duration (30 min) of the binder-free V2O5@CFC-30 electrode showed an excellent performance with a high areal capacitance of 354 mF/cm2 in 1 M Na2SO4 aqueous electrolyte. Furthermore, the asymmetric supercapacitor (ASC) was developed using V2O5@CFC-30 as a positive electrode and O, N, S enriched activated carbon (O, N, S@AC) as a negative electrode. The ASC demonstrated a maximum device-specific capacitance of 57 F/g, excellent cyclic stability (~94%) even after 10,000 cycles and maximum specific energy (17.7 Wh/kg) and power (2728 W/kg). Furthermore, the flexible supercapacitor delivered maximum specific energy (13 Wh/kg) and power (3871 W/kg) with an outstanding capacity retention of 91% over 4000 cycles. This research makes the electrodeposition of V2O5 ideally suited for a binder-free, high performance supercapacitor applications

Synergetic effect induced/tuned bimetallic nanoparticles (Pt-Ni) anchored graphene as a catalyst for oxygen reduction reaction and scalable SS-314L serpentine flow field proton exchange membrane fuel cells (PEMFCs)

© 2022 Elsevier. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/A simple design of electroactive and cost-effective electrocatalysts for oxygen reduction reaction (ORR) activity is crucial towards energy conversion in the commercialization of proton exchange membrane fuel cells (PEMFCs). Herein, we synthesized a stable electroactive bimetallic catalyst of Ni anchored with low loading of Pt nanoparticles, and graphene used as a supportive material for catalyst integration (Pt3-Ni/G). It exhibited maximum electrochemical surface area (ECSA, 108.56 m2/gPt), mass activity (2.2 A mgPt) and specific activity (3.47 mA cm-2), signifying an excellent ORR activity. In addition, a scalable PEMFC fabrication through 0.2 mgPtcm-2 Pt3-Ni/G as cathode with an active area of 25 cm2 and stainless steel-314L (SS-314L) used as a serpentine flow field. This strategy provides a maximum power output of 71.25 W mgPt-1 at current density 1.59 A cm-2. In addition, Pt3-Ni/C//Pt/C, based PEMFC system delivered a constant power output (68.75 W mgPt-1) even after 4 h of continuous cycling.This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2014R1A6A1030419). This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. 2020112382). The authors also wish to acknowledge the support and facilities offered by the PSG management, PSG Institute of Advanced Studies, PSG Sons & Charities, Coimbatore, India.Peer ReviewedPostprint (published version

Engineering redox active sites enriched 3D-on-2D bimetallic double layered hydroxide electrode for supercapatteries

DOI link format: http://dx.doi.org/10.1016/j.mtener.2022.101182 © 2022 Elsevier. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/The functionalization of structural nanoengineered battery-type electrodes has aided the emergence of supercapattery (SCp) subclass, which enables a wide range of applications. Herein, our research work provides a platform for two-step fabrication of nanoengineered 3D-on-2D structure as a promising approach to obtain high-performance battery-type electrodes. The hierarchical 2D NiCo bimetallic LDH NC(12)40 electrode was fabricated using electrodeposition, while the nanoengineered 3D ZIF-67 on 2D LDH electrode was achieved via pseudomorphic replication techniques. The fabricated 3D-on-2D NC(12)40-30 electrode reveals a maximum areal capacity of 1044 mC cm-2 at a current density of 4 mA cm-2 in 6 M KOH electrolyte. Furthermore, NC(12)40-30//AC was integrated as a SCp device, achieving a maximum specific capacitance of 63 F/g and maximum specific energy and power of 20.5 W/h/kg and 8522.7 W/kg, respectively, with improved capacitance retention (85%) even after 10,000 cycles. Thus, the assembled SCp coin cell displays 18-LED illumination in four different commercial LED colors, indicating the viability of the battery-type electrode for SCp development.This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2014R1A6A1030419) and by the National Research Foundation of Korea (NRF) Grant funded by the Korean government (MSIT) (No. 2020112382). This work has been partially supported by the Spanish government under project PID2019-109215RB-C41 (SCALED).Peer ReviewedPostprint (author's final draft

Selenium enriched hybrid metal chalcogenides with enhanced redox kinetics for high-energy density supercapacitors

© 2021 Elsevier. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Rational design and synergistic interactions between the electrode and electroactive materials have a huge impact on elevating the energy storage performance of supercapacitor devices. Herein, selenium enriched hybrid NiSe2@Fe3Se4 (NFS) nanocomposites have been facilely deposited on Ni-foam using chemical bath deposition (CBD) technique. The NiSe2@Fe3Se4 hybrid composites exhibited better electrochemical performance than that of monometallic selenides (NiSe2 and Fe3Se4), which can be attributed to the synergy effect and improved conductivity of polymetallic ions over the Ni foam substrate. The effect of NFS deposition time on Ni foam was studied and it greatly influences the morphological and electrochemical performances. Specifically, the NFS deposited for 36 h (NFS@36 h) provides a maximum areal capacity of 6.05 C cm-2 at 6 mA cm-2, which is almost four-fold higher than that of pure NiSe2 (0.168 C cm-2) and Fe3Se4 (1.46 C cm-2). Furthermore, a hybrid supercapacitor (HSC) is assembled utilizing the NFS@36 h as a positive electrode and biomass derived O, N enriched activated carbon as a negative electrode with an aqueous electrolyte. With a high-mass loading of 21.5 mg cm-2, the device demonstrates superior specific energy of 52 W h kg-1 at 398 W kg-1 specific power and even maintained 19 W h kg-1 at a maximum specific 8000 W kg-1. Furthermore, the device exhibited excellent cycling durability with ~ 92% of specific capacitance retention for 10,000 charge/discharge cycles at 5 A g-1. Besides, the HSCs have been successfully illuminated several light emitting diodes (LEDs) and portable displays demonstrating superior energy storage performance.Peer ReviewedPostprint (author's final draft