Journal of Electrochemical Energy Conversion and Storage
ISSN / EISSN : 2381-6872 / 2381-6910
Published by: ASME International (10.1115)
Total articles ≅ 342
Latest articles in this journal
Published: 13 October 2021
Journal of Electrochemical Energy Conversion and Storage, Volume 19, pp 1-23; https://doi.org/10.1115/1.4052534
The constant voltage cold start of the proton exchange membrane fuel cell (PEMFC) is usually operated at a low start-voltage in order to ensure high heat generation, which can shorten the process of the PEMFC cold start. However, the effect of constant voltage cold start on the durability of PEMFC is still unclear. Thus, in this work, the PEMFC is tested repeatedly at a low start-voltage to simulate its actual operating state in the vehicle. Then, the effect of the PEMFC durability under constant voltage cold start is investigated by polarization curve, cyclic voltammetry, electrochemical impedance spectroscopy, transmission electron microscope, and ion chromatography. After the repeatedly cold start, the output performance of the PEMFC decreases significantly. According to the characterization results, the degradation mechanism of the PEMFC at the constant voltage cold start is demonstrated to be that the PEMFC start-up repeatedly at low start-voltage leads to the decomposition of membrane polymer structure and promotes the crossover of H2. Meanwhile, the PEMFC start-up repeatedly at low start-voltage also leads to the agglomeration of catalysts, which reduces the active area of catalysts and ultimately results in the degradation of fuel cell performance. Above all, this study proves that the durability of PEMFC can be shortened by the constant voltage cold start at 0.1 V, which provides a reference for the development of the PEMFC cold start control strategy.
Published: 13 October 2021
Journal of Electrochemical Energy Conversion and Storage, Volume 19, pp 1-12; https://doi.org/10.1115/1.4052535
Accurate estimation of the state of health (SOH) is an important guarantee for safe and reliable battery operation. In this paper, an online method based on indirect health features (IHFs) and sparrow search algorithm fused with deep extreme learning machine (SSA-DELM) of lithium-ion batteries is proposed to estimate SOH. First, the temperature and voltage curves in the battery discharge data are acquired, and the optimal intervals are obtained by ergodic method. Discharge temperature difference at equal time intervals (DTD-ETI) and discharge time interval with equal voltage difference (DTI-EVD) are extracted as IHF. Then, the input weights and hidden layer thresholds of the DELM algorithm are optimized using SSA, and the SSA-DELM model is applied to the estimation of battery's SOH. Finally, the established model is experimentally validated using the battery data, and the results show that the method has high prediction accuracy, strong algorithmic stability, and good adaptability.
Published: 13 October 2021
Journal of Electrochemical Energy Conversion and Storage, Volume 19, pp 1-9; https://doi.org/10.1115/1.4052464
The interfacial reactivity and resistance between the cathode and the solid-state electrolyte (SSE) of a solid-state battery (SSB) usually lead to quite poor cycling performance and fast capacity decay. Hence, cathode coatings are generally applied to reduce cathode/SSE interfacial impedance in SSBs. In recent years, based on high-throughput screening, several promising coating materials have been recognized. In the present work, density functional theory (DFT) calculations were conducted on LiH2PO4 and LiTi2(PO4)3 to examine their characteristics as potential cathode coating materials. It was found that both of these materials had high oxidation potentials (>4.5 V), good chemical stability against the electrolyte and the cathode, reasonable ionic conductivity, and wide bandgaps; therefore, they can be used as outstanding cathode coating materials for SSBs.
Published: 5 October 2021
Journal of Electrochemical Energy Conversion and Storage, Volume 19, pp 1-33; https://doi.org/10.1115/1.4052533
Water splitting is considered as a potential sustainable and green technology for producing mass hydrogen and oxygen. A cost-effective self-supported stable electrocatalyst with excellent electrocatalytic performance in a wide pH range is greatly required for water splitting. This work reports on the synthesis and anchoring of Fe1CoxNiyP nanoparticles on vertically aligned reduced graphene oxide array (VrGO) via electroless plating. The catalytic activity of Fe1CoxNiyP nanoparticles is tuned finely by tailoring the cationic ratio of Co and Ni. Fe1Co2Ni1P/VrGO exhibits the lowest overpotential (109 and 139 mV) at 10 mA cm−2 and lowest tafel slope (133 and 31 mV dec−1) for hydrogen evolution reaction in 1.0 M KOH and 0.5 M H2SO4, respectively. Fe1Co1Ni2P/VrGO exhibits the lowest overpotential (342 mV) at 10 mA cm−2 with lowest tafel slope (60 mV dec−1) for oxygen evolution reaction. The enhanced performance of the electrocatalyst is attributed to improved electrical conductivity, synergistic effects, and beneficial electronic states caused by the appropriate atomic ratio of Co and Ni in the bifunctional electrocatalyst. This study helps to explore the effect of variable cationic ratio in the cost-effective ternary iron group metal phosphides electrocatalysts to achieve enhanced electrocatalytic performance for water splitting in a wide pH range.
Published: 1 October 2021
Journal of Electrochemical Energy Conversion and Storage pp 1-15; https://doi.org/10.1115/1.4052628
Lithium-ion traction batteries are increasingly use in transportation such as electric vehicles and buses. In order to reduce the life cycle cost of traction battery, material recycling is a technical route that must be considered. Deep-discharge is one of the necessary steps in the process of battery disassembly and material recycle, but the thermal stability and internal material changes caused by deep discharge will affect the subsequent recycle processes. In this paper, we study the influence of deep-discharge rate on recycle process of a commercial traction battery with LiNi1/3Co1/3Mn1/3O2 cathode and graphite anode. Combine with multi-analysis methods, the evolution of an electrode structure under different deep-discharge current densities is systematically studied. The results show that the deep-discharge current density will have different effects on the internal structure of the battery and will affect its thermal safety.
Published: 1 October 2021
Journal of Electrochemical Energy Conversion and Storage pp 1-26; https://doi.org/10.1115/1.4052629
The structure of the cathode catalyst layer (CCL) is critically important for improving the performance, durability, and stability of polymer electrolyte fuel cells. In this study, we designed CCLs with a three-dimensional (3D) structure that could increase the surface area of the CCLs to decrease their oxygen transfer resistance. The CCLs were fabricated using the inkjet printing method, and the electrochemical performance of the CCLs in a membrane electrode assembly was evaluated using an actual cell. The results showed that at high Pt loadings, the performance of the CCL with the 3D structure was better than that with the flat structure. In particular, at the high current density, which is related to mass transport resistance, the two structures exhibited a large difference in performance. At the Pt loading of 0.3 mg/cm2, the CCL with the 3D structure showed the highest maximum power density among all the CCLs investigated in this study. This indicates that the 3D structure decreased the oxygen transfer resistance of the CCL. The results indicated that the 3D structure provided the improved morphological and microstructural characteristics to the CCL for fuel cell applications.
Published: 29 September 2021
Journal of Electrochemical Energy Conversion and Storage, Volume 18, pp 1-2; https://doi.org/10.1115/1.4052531
The increasing population growth, depletion of natural resources, and rising energy demand have sparked enormous research endeavors in electrochemical energy storage and conversion. For example, rechargeable lithium-ion batteries are ubiquitous in everyday life. Mechanics plays a critical role in designing a wide range of energy technologies. The emerging field of electro-chemo-mechanics, the interplay of mechanics and electrochemistry, is crucial for understanding the coupled physiochemical processes. The electrochemical phenomena can govern the mechanical response such as stress generation, deformation, fracture initiation/propagation, elasticity, plasticity, etc. Similarly, mechanical phenomena also influence the electrochemical properties such as device reliability, durability, etc. Therefore, the in-depth mechanical study of electrochemical systems is urgently necessary for fundamental science and technological applications. Over the past few years, there has been significant progress in modeling, theories, and experimental characterizations of mechanical aspects of energy storage and conversion. This timely special issue addressed some recent advances in electro-chemo-mechanics. We have selected eight papers covering a wide range of issues in batteries and fuel cells such as (i) deformation, microstructural changes, creep, overcharge detection and prevention, optimization of structural parameters in batteries, (ii) temperature and load variations, metal-free cathode catalyst in fuel cells. The selected papers cover a gamut of electrochemical-mechanics centric research in energy storage and conversion.
Published: 24 September 2021
Journal of Electrochemical Energy Conversion and Storage, Volume 19, pp 1-17; https://doi.org/10.1115/1.4052313
A water-based tape-casting slurry is reported to prepare the ceria and scandia co-doped zirconia (ScSZ) electrolyte films. The slurry is characterized and optimized through Zeta potential and rheological property measurements. Smooth and flat ScSZ electrolyte films are obtained by improving the sintering process. The microstructure, electrical performance, and mechanical property of ScSZ with adding different contents of Al2O3 are also investigated. The results show that a proper amount of Al2O3 has a beneficial effect on the densification of ScSZ. A significant decrease in the grain boundary resistance of ScSZ is observed by adding 0.5 wt% Al2O3. The bending strength of the sample with 0.5 wt% Al2O3 (ScSZ-0.5A) is about 400 MPa, which is 20% higher than pure ScSZ. The ScSZ-0.5A electrolyte film fabricated by the water-based tape-casting method shows appropriate electrical conductivity and high mechanical strength, which is promising for practical application in solid oxide fuel cells (SOFCs).
Published: 3 September 2021
Journal of Electrochemical Energy Conversion and Storage, Volume 19; https://doi.org/10.1115/1.4052162
Heteroatom doping is an effective modification to improve electrochemical performance of carbon materials as electrodes in storage devices and multi-doping works better because of the synergistic effect. In this report, N/O/S multi-doped carbon nanospheres (SLS/PANI-700) are prepared from crosslinking hydrogel beads of polyaniline and sodium lignosulfonate. The addition of sodium lignosulfonate improves the electrochemical performance of PANI-based carbon significantly by changing micromorphology, building interconnected network, and offering diverse doping. SLS/PANI-700 has an ultrahigh specific surface area of 2861 m2 g−1, well-developed hierarchically porous structure, interconnected conducting carbon network, and high N and O concentration. Take these advantages, it delivers a very high capacitance of 487.7 F g−1 at 1 A g−1, and a superior rate retention with a capacitance of 373.6 F g−1 at a high current density of 20 A g−1 as electrode material. The assembled symmetric supercapacitor device exhibits a very high energy density of 43.68 Wh kg−1 at 488.98 W kg−1 and keeps 21.18 Wh kg−1 under a high power density of 8664.54 W kg−1. Based on these properties, SLS/PANI-700 possesses great promising potential as electrode material for advanced supercapacitors.
Published: 2 September 2021
Journal of Electrochemical Energy Conversion and Storage pp 1-16; https://doi.org/10.1115/1.4052316
Due to the low specific capacitance and small specific surface area of conventional carbon materials used as electrode materials for double-layer capacitors, the search for more ideal materials and ingenious preparation methods remains a major challenge. In this study, fractional porous carbon nanosheets were prepared by co-doping Fe and N with chitosan as nitrogen source. The advantage of this method is that the carbon nanosheets can have a large number of pore structures and produce a large specific surface area. The presence of Fe catalyzes the graphitization of carbon in the carbon layer during carbonization process, and further increases the specific surface area of the electrode material. This structure provides an efficient ion and electron transport pathway, which enables more active sites to participate in the REDOX reaction, thus significantly enhancing the electrochemical performance of SCs. The specific surface area of CS-800 is up to 1587 m2 g−1. When the current density is 0.5 A g−1, the specific capacitance of CS-800 reaches 308.84 F g−1, and remains 84.61 % of the initial value after 10,000 cycles. The Coulomb efficiency of CS-800 is almost 100 % after a long cycle, which indicates that CS-800 has more ideal double-layer capacitance and pseudo capacitance.