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Frontiers in Energy
Journal Prestige (SJR): 0.292  Citation Impact (citeScore): 1 Number of Followers: 4  Hybrid journal (It can contain Open Access articles)ISSN (Print) 2095-1701 - ISSN (Online) 2095-1698 Published by Springer-Verlag  [2468 journals]
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- Oxygen reduction electrocatalysis: From conventional to single-atomic
platinum-based catalysts for proton exchange membrane fuel cells-
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Abstract: Abstract Platinum (Pt)-based materials are still the most efficient and practical catalysts to drive the sluggish kinetics of cathodic oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs). However, their catalysis and stability performance still need to be further improved in terms of corrosion of both carbon support and Pt catalyst particles as well as Pt loading reduction. Based on the developed synthetic strategies of alloying/nanostructuring Pt particles and modifying/innovating supports in developing conventional Pt-based catalysts, Pt single-atom catalysts (Pt SACs) as the recently burgeoning hot materials with a potential to achieve the maximum utilization of Pt are comprehensively reviewed in this paper. The design thoughts and synthesis of various isolated, alloyed, and nanoparticle-contained Pt SACs are summarized. The single-atomic Pt coordinating with non-metals and alloying with metals as well as the metal-support interactions of Pt single-atoms with carbon/non-carbon supports are emphasized in terms of the ORR activity and stability of the catalysts. To advance further research and development of Pt SACs for viable implementation in PEMFCs, various technical challenges and several potential research directions are outlined.
PubDate: 2023-11-20
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- Recent advances and challenges of nitrogen/nitrate electro catalytic
reduction to ammonia synthesis-
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Abstract: Abstract The Haber-Bosch process is the most widely used synthetic ammonia technology at present. Since its invention, it has provided an important guarantee for global food security. However, the traditional Haber-Bosch ammonia synthesis process consumes a lot of energy and causes serious environmental pollution. Under the serious pressure of energy and environment, a green, clean, and sustainable ammonia synthesis route is urgently needed. Electrochemical synthesis of ammonia is a green and mild new method for preparing ammonia, which can directly convert nitrogen or nitrate into ammonia using electricity driven by solar, wind, or water energy, without greenhouse gas and toxic gas emissions. Herein, the basic mechanism of the nitrogen reduction reaction (NRR) to ammonia and nitrate reduction reaction (NO 3 − RR) to ammonia were discussed. The representative approaches and major technologies, such as lithium mediated electrolysis and solid oxide electrolysis cell (SOEC) electrolysis for NRR, high activity catalyst and advanced electrochemical device fabrication for NO 3 − RR and electrochemical ammonia synthesis were summarized. Based on the above discussion and analysis, the main challenges and development directions for electrochemical ammonia synthesis were further proposed.
PubDate: 2023-11-20
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- Machine learning and neural network supported state of health simulation
and forecasting model for lithium-ion battery-
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Abstract: Abstract As the intersection of disciplines deepens, the field of battery modeling is increasingly employing various artificial intelligence (AI) approaches to improve the efficiency of battery management and enhance the stability and reliability of battery operation. This paper reviews the value of AI methods in lithium-ion battery health management and in particular analyses the application of machine learning (ML), one of the many branches of AI, to lithium-ion battery state of health (SOH), focusing on the advantages and strengths of neural network (NN) methods in ML for lithium-ion battery SOH simulation and prediction. NN is one of the important branches of ML, in which the application of NNs such as backpropagation NN, convolutional NN, and long short-term memory NN in SOH estimation of lithium-ion batteries has received wide attention. Reports so far have shown that the utilization of NN to model the SOH of lithium-ion batteries has the advantages of high efficiency, low energy consumption, high robustness, and scalable models. In the future, NN can make a greater contribution to lithium-ion battery management by, first, utilizing more field data to play a more practical role in health feature screening and model building, and second, by enhancing the intelligent screening and combination of battery parameters to characterize the actual lithium-ion battery SOH to a greater extent. The in-depth application of NN in lithium-ion battery SOH will certainly further enhance the science, reliability, stability, and robustness of lithium-ion battery management.
PubDate: 2023-11-20
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- Cluster voltage control method for “Whole County” distributed
photovoltaics based on improved differential evolution algorithm-
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Abstract: Abstract China is vigorously promoting the “whole county promotion” of distributed photovoltaics (DPVs). However, the high penetration rate of DPVs has brought problems such as voltage violation and power quality degradation to the distribution network, seriously affecting the safety and reliability of the power system. The traditional centralized control method of the distribution network has the problem of low efficiency, which is not practical enough in engineering practice. To address the problems, this paper proposes a cluster voltage control method for distributed photovoltaic grid-connected distribution network. First, it partitions the distribution network into clusters, and different clusters exchange terminal voltage information through a “virtual slack bus.” Then, in each cluster, based on the control strategy of “reactive power compensation first, active power curtailment later,” it employs an improved differential evolution (IDE) algorithm based on Cauchy disturbance to control the voltage. Simulation results in two different distribution systems show that the proposed method not only greatly improves the operational efficiency of the algorithm but also effectively controls the voltage of the distribution network, and maximizes the consumption capacity of DPVs based on qualified voltage.
PubDate: 2023-11-12
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- Plasma spray coating on interconnector toward promoted solid oxide fuel
cells and solid oxide electrolysis cells-
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Abstract: Abstract Interconnector is a critical component to construct solid oxide cells (SOCs) stack. Oxidation of metallic interconnectors and Cr poisoning caused by oxidation are important factors that lead to long-term performance degradation of SOCs. Coating on the interconnector surface is an important approach to inhibit the oxidation and Cr migration of the interconnector. Herein, (La0.75Sr0.25)0.95MnO3−δ (LSM) and Mn1.5Co1.5O4 (MCO) are used to fabricate the coatings of interconnector. Two advanced thermal spray technology, atmospheric plasma spraying (APS) and low-pressure plasma spray (LPPS), are adopted for the coating preparation. The electrochemical performance, rising and cooling cycle stability, and Cr diffusion inhibition performance of the coatings are tested and evaluated. The result indicates that MCO can generate more uniform and denser coatings than LSM. In addition, MCO coatings prepared by LPPS shows the best electrochemical performance, rising and cooling cycle stability, and Cr diffusion inhibition. The initial area specific resistance (ASR) is 0.0027 Ω·cm2 at 800 °C. After 4 cooling cycle tests, the ASR increases to 0.0032 Ω·cm2 but lower than other samples. Meanwhile, the relative intense of Cr at the interface of SUS430 with MCO coatings fabricated by LPPS is lower than that of MCO fabricated by APS after 4 rising and cooling cycle operations, showing more favorable Cr diffusion inhibition performance.
PubDate: 2023-11-10
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- Alumina modified sodium vanadate cathode for aqueous zinc-ion batteries
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Abstract: Abstract Aqueous zinc-ion batteries (ZIBs) have great prospects for widespread application in massive scale energy storage. By virtue of the multivalent state, open frame structure and high theoretical specific capacity, vanadium (V)-based compounds are a kind of the most developmental potential cathode materials for ZIBs. However, the slow kinetics caused by low conductivity and the capacity degradation caused by material dissolution still need to be addressed for large-scale applications. Therefore, sodium vanadate Na2V6O16·3H2O (NVO) was chosen as a model material, and was modified with alumina coating through simple mixing and stirring methods. After Al2O3 coating modification, the rate capability and long-cycle stability of Zn//NVO@Al2O3 battery have been significantly improved. The discharge specific capacity of NVO@Al2O3 reach up to 228 mAh/g (at 4 A/g), with a capacity reservation rate of approximately 68% after 1000 cycles, and the Coulombic efficiency (CE) is close to 100%. As a comparison, the capacity reservation rate of Zn//NVO battery is only 27.7%. Its superior electrochemical performance is mainly attributed to the Al2O3 coating layer, which can increase zinc-ion conductivity of the material surface, and to some extent inhibit the dissolution of NVO, making the structure stable and improving the cyclic stability of the material. This paper offers new prospects for the development of cathode coating materials for ZIBs.
PubDate: 2023-10-30
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- Mapping the trends and prospects of battery cathode materials based on
patent landscape-
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Abstract: Abstract Advancing portable electronics and electric vehicles is heavily dependent on the cutting-edge lithium-ion (Li-ion) battery technology, which is closely linked to the properties of cathode materials. Identifying trends and prospects of cathode materials based on patent analysis is considered a kernel to optimize and refine battery related markets. In this paper, a patent analysis is performed on 6 popular cathode materials by comprehensively considering performance comparison, development trend, annual installed capacity, technology life cycle, and distribution among regions and patent assignees. In the technology life cycle, the cathode materials majorly used in electric vehicle have entered maturity stage, while the lithium cobalt oxide (LCO) cathode that is widely used in portable electronics is still in the growth stage. In global patent distributions, China holds more than 50% of total patents. In the top 10 patent assignees of 6 cathode materials, 2 institutes are from China with the rest being Japan (6) and Republic of Korea (2), indicating that the technology of cathode materials in China is relatively scattered while cathode research is highly concentrated in Japan and Republic of Korea. Moreover, the patent distribution has to consider practical issues as well as the impacts of core patents. For example, the high cost discourages the intention of applying international patents. This paper is expected to stimulate battery research, understand technical layout of various countries, and probably forecast innovative technology breakthroughs.
PubDate: 2023-10-30
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- Sulfur and carbon co-doped g-C3N4 microtubes with enhanced photocatalytic
H2 production activity-
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Abstract: Abstract Metal-free graphitic carbon nitride (g-C3N4) has captured significant attention as a low-cost and efficient hydrogen production photocatalyst through. Effectively regulating the microstructure and accelerating the separation of photogenerated carriers remain crucial strategies for promoting the photocatalytic performance of this material. Herein, a novel sulfur–carbon co-doped g-C3N4 (SCCN) hierarchical microtubules filled with abundant nanosheets inside by thermal polymerization is reported. Numerous nanosheets create abundant pores and cavities inside the SCCN microtubes, thereby increasing the specific surface area of g-C3N4 and providing sufficient reactant attachment sites. Besides, the hierarchical structure of SCCN microtubules strengthens the reflection and scattering of light, and the utilization of visible light is favorably affected. More importantly, co-doping S and C has greatly improved the photocatalytic performance of graphitic carbon nitride, optimized the band gap structure and enhanced the photogenerated carrier splitting. Consequently, the SCCN exhibits a remarkable photocatalytic H2 evolution rate of 4868 µmol/(g·h). This work demonstrates the potential of multi-nonmetal doped g-C3N4 as the ideal photocatalyst for H2 evolution.
PubDate: 2023-10-20
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- Automotive revolution and carbon neutrality
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Abstract: Abstract The automotive industry is in the midst of a groundbreaking revolution, driven by the imperative to achieve intelligent driving and carbon neutrality. A crucial aspect of this transformation is the transition to electric vehicles (EVs), which necessitates widespread changes throughout the entire automotive ecosystem. This paper examines the challenges and opportunities of this transition, including automotive electrification, intelligence-connected transportation system, and the potential for new technologies such as hydrogen fuel cells. Meanwhile, it discusses the key technologies and progress of the hydrogen energy industry chain in the upstream hydrogen production, midstream hydrogen storage and transportation, downstream hydrogen station construction and hydrogen fuel cells in turn. Finally, it proposes the directions for future layout, providing guidance for future development.
PubDate: 2023-10-20
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- Electrochemical CO2 reduction to C2+ products over Cu/Zn intermetallic
catalysts synthesized by electrodeposition-
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Abstract: Abstract Electrocatalytic CO2 reduction (ECR) offers an attractive approach to realizing carbon neutrality and producing valuable chemicals and fuels using CO2 as the feedstock. However, the lack of cost-effective electrocatalysts with better performances has seriously hindered its application. Herein, a one-step co-electrodeposition method was used to introduce Zn, a metal with weak *CO binding energy, into Cu to form Cu/Zn intermetallic catalysts (Cu/Zn IMCs). It was shown that, using an H-cell, the high Faradaic efficiency of C2+ hydrocarbons/alcohols \(({\rm{F}}{{\rm{E}}_{{{\rm{C}}_{2 + }}}})\) could be achieved in ECR by adjusting the surface metal components and the applied potential. In suitable conditions, FEC2+ and current density could be as high as 75% and 40 mA/cm2, respectively. Compared with the Cu catalyst, the Cu/Zn IMCs have a lower interfacial charge transfer resistance and a larger electrochemically active surface area (ECSA), which accelerate the reaction. Moreover, the *CO formed on Zn sites can move to Cu sites due to its weak binding with *CO, and thus enhance the C–C coupling on the Cu surface to form C2+ products.
PubDate: 2023-10-20
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- Rise of aluminum-chalcogen batteries: A promising path to sustainable
energy storage-
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PubDate: 2023-10-01
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- In-MOF-derived In2S3/Bi2S3 heterojunction for enhanced photocatalytic
hydrogen production-
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Abstract: Abstract Transition metal sulfides are commonly studied as photocatalysts for water splitting in solar-to-fuel conversion. However, the effectiveness of these photocatalysts is limited by the recombination and restricted light absorption capacity of carriers. In this paper, a broad spectrum responsive In2S3/Bi2S3 heterojunction is constructed by in-situ integrating Bi2S3 with the In2S3, derived from an In-MOF precursor, via the high-temperature sulfidation and solvothermal methods. Benefiting from the synergistic effect of wide-spectrum response, effective charge separation and transfer, and strong heterogeneous interfacial contacts, the In2S3/Bi2S3 heterojunction demonstrates a rate of 0.71 mmol/(g·h), which is 2.2 and 1.7 times as much as those of In2S3 (0.32 mmol/(g·h) and Bi2S3 (0.41 mmol/(g·h)), respectively. This paper provides a novel idea for rationally designing innovative heterojunction photocatalysts of transition metal sulfides for photocatalytic hydrogen production.
PubDate: 2023-10-01
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- A comprehensive review of wind power based power system frequency
regulation-
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Abstract: Abstract Wind power (WP) is considered as one of the main renewable energy sources (RESs) for future low-carbon and high-cost-efficient power system. However, its low inertia characteristic may threaten the system frequency stability of the power system with a high penetration of WP generation. Thus, the capability of WP participating in the system frequency regulation has become a research hotspot. In this paper, the impact of WP on power system frequency stability is initially presented. In addition, various existing control strategies of WP participating in frequency regulation are reviewed from the wind turbine (WT) level to the wind farm (WF) level, and their performances are compared in terms of operating principles and practical applications. The pros and cons of each control strategy are also discussed. Moreover, the WP combing with energy storage system (ESS) for system frequency regulation is explored. Furthermore, the prospects, future challenges, and solutions of WP participating in power system frequency regulation are summarized.
PubDate: 2023-10-01
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- Combustion and emissions of RP-3 jet fuel and diesel fuel in a
single-cylinder diesel engine-
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Abstract: Abstract The combustion characteristics and emission behaviors of RP-3 jet fuel were studied and compared to commercial diesel fuel in a single-cylinder compression ignition (CI) engine. Engine operational parameters, including engine load (0.6, 0.7, and 0.8 MPa indicating the mean effective pressure (IMEP)), the exhaust gas recirculation (EGR) rate (0%, 10%, 20%, and 30%), and the fuel injection timing ( - 20, - 15, - 10, and - 5° crank angle (CA) after top dead center (ATDC)) were adjusted to evaluate the engine performances of RP-3 jet fuel under changed operation conditions. In comparison to diesel fuel, RP-3 jet fuel shows a retarded heat release and lagged combustion phase, which is more obvious under heavy EGR rate conditions. In addition, the higher premixed combustion fraction of RP-3 jet fuel leads to a higher firststage heat release peak than diesel fuel under all testing conditions. As a result, RP-3 jet fuel features a longer ignition delay (ID) time, a shorter combustion duration (CD), and an earlier CA50 than diesel fuel. The experimental results manifest that RP-3 jet fuel has a slightly lower indicated thermal efficiency (ITE) compared to diesel fuel, but the ITE difference becomes less noticeable under large EGR rate conditions. Compared with diesel fuel, the nitrogen oxides (NOx) emissions of RP-3 jet fuel are higher while its soot emissions are lower. The NOx emissions of RP-3 can be effectively reduced with the increased EGR rate and delayed injection timing.
PubDate: 2023-10-01
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- A methodology for regulating fuel stratification and improving fuel
economy of GCI mode via double main-injection strategy-
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Abstract: Abstract Gasoline compression ignition (GCI) combustion faces problems such as high maximum pressure rise rate (MPRR) and combustion deterioration at high loads. This paper aims to improve the engine performance of the GCI mode by regulating concentration stratification and promoting fuel-gas mixing by utilizing the double main-injection (DMI) strategy. Two direct injectors simultaneously injected gasoline with an octane number of 82.7 to investigate the energy ratio between the two main-injection and exhaust gas recirculation (EGR) on combustion and emissions. High-load experiments were conducted using the DMI strategy and compared with the single main-injection (SMI) strategy and conventional diesel combustion. The results indicate that the DMI strategy have a great potential to reduce the MPRR and improve the fuel economy of the GCI mode. At a 10 bar indicated mean effective pressure, increasing the main-injection-2 ratio (Rm−2) shortens the injection duration and increases the mean mixing time. Optimized Rm−2 could moderate the trade-off between the MPRR and the indicated specific fuel consumption with both reductions. An appropriate EGR should be adopted considering combustion and emissions. The DMI strategy achieves a highly efficient and stable combustion at high loads, with an indicated thermal efficiency (ITE) greater than 48%, CO and THC emissions at low levels, and MPRR within a reasonable range. Compared with the SMI strategy, the maximum improvement of the ITE is 1.5%, and the maximum reduction of MPRR is 1.5 bar/°CA.
PubDate: 2023-10-01
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- Three-dimensional composite Li metal anode by simple mechanical
modification for high-energy batteries-
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Abstract: Abstract Lithium (Li) metal is believed to be the “Holy Grail” among all anode materials for next-generation Li-based batteries due to its high theoretical specific capacity (3860 mAh/g) and lowest redox potential (−3.04 V). Disappointingly, uncontrolled dendrite formation and “hostless” deposition impede its further development. It is well accepted that the construction of three-dimensional (3D) composite Li metal anode could tackle the above problems to some extent by reducing local current density and maintaining electrode volume during cycling. However, most strategies to build 3D composite Li metal anode require either electrodeposition or melt-infusion process. In spite of their effectiveness, these procedures bring multiple complex processing steps, high temperature, and harsh experimental conditions which cannot meet the actual production demand in consideration of cost and safety. Under this condition, a novel method to construct 3D composite anode via simple mechanical modification has been recently proposed which does not involve harsh conditions, fussy procedures, or fancy equipment. In this mini review, a systematic and in-depth investigation of this mechanical deformation technique to build 3D composite Li metal anode is provided. First, by summarizing a number of recent studies, different mechanical modification approaches are classified clearly according to their specific procedures. Then, the effect of each individual mechanical modification approach and its working mechanisms is reviewed. Afterwards, the merits and limits of different approaches are compared. Finally, a general summary and perspective on construction strategies for next-generation 3D composite Li anode are presented.
PubDate: 2023-10-01
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- Selective preparation for biofuels and high value chemicals based on
biochar catalysts-
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Abstract: Abstract The reuse of biomass wastes is crucial toward today’s energy and environmental crisis, among which, biomass-based biochar as catalysts for biofuel and high value chemical production is one of the most clean and economical solutions. In this paper, the recent advances in biofuels and high chemicals for selective production based on biochar catalysts from different biomass wastes are critically summarized. The topics mainly include the modification of biochar catalysts, the preparation of energy products, and the mechanisms of other high-value products. Suitable biochar catalysts can enhance the yield of biofuels and higher-value chemicals. Especially, the feedstock and reaction conditions of biochar catalyst, which affect the efficiency of energy products, have been the focus of recent attentions. Mechanism studies based on biochar catalysts will be helpful to the controlled products. Therefore, the design and advancement of the biochar catalyst based on mechanism research will be beneficial to increase biofuels and the conversion efficiency of chemicals into biomass. The advanced design of biochar catalysts and optimization of operational conditions based on the biomass properties are vital for the selective production of high-value chemicals and biofuels. This paper identifies the latest preparation for energy products and other high-value chemicals based on biochar catalysts progresses and offers insights into improving the yield of high selectivity for products as well as the high recyclability and low toxicity to the environment in future applications.
PubDate: 2023-10-01
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- Conversion of polyethylene to gasoline: Influence of porosity and acidity
of zeolites-
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Abstract: Abstract Plastic waste is causing serious environmental problems. Developing efficient, cheap and stable catalytic routes to convert plastic waste into valuable products is of great importance for sustainable development, but remains to be a challenging task. Zeolites are cheap and stable, but they are usually not efficient for plastic conversion at a low temperature. Herein a series of microporous and mesoporous zeolites were used to study the influence of porosity and acidity of zeolite on catalytic activity for plastics conversion. It was observed that H-Beta zeolite was an efficient catalyst for cracking high-density polyethylene to gasoline at 240 °C, and the products were almost C4-C12 alkanes. The effect of porosity and acidity on catalytic performance of zeolites was evaluated, which clearly visualized the good performance of H-Beta due to high surface area, large channel system, large amount accessible acidic sites. This study provides very useful information for designing zeolites for efficient conversion of plastics.
PubDate: 2023-09-30
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- Emerging trends in self-healable nanomaterials for triboelectric
nanogenerators: A comprehensive review and roadmap-
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Abstract: Abstract A thorough analysis of triboelectric nanogenerators (TENGs) that make use of self-healable nanomaterials is presented in this review. These TENGs have shown promise as independent energy sources that do not require an external power source to function. TENGs are developing into a viable choice for powering numerous applications as low-power electronics technology advances. Despite having less power than conventional energy sources, TENGs do not directly compete with these. TENGs, on the other hand, provide unique opportunities for future self-powered systems and might encourage advancements in energy and sensor technologies. Examining the many approaches used to improve nanogenerators by employing materials with shape memory and self-healable characteristics is the main goal of this review. The findings of this comprehensive review provide valuable information on the advancements and possibilities of TENGs, which opens the way for further research and advancement in this field. The discussion of life cycle evaluations of TENGs provides details on how well they perform in terms of the environment and identifies potential improvement areas. Additionally, the cost-effectiveness, social acceptability, and regulatory implications of self-healing TENGs are examined, as well as their economic and societal ramifications.
PubDate: 2023-09-30
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- Production of hydrogen from fossil fuel: A review
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Abstract: Abstract Production of hydrogen, one of the most promising alternative clean fuels, through catalytic conversion from fossil fuel is the most technically and economically feasible technology. Catalytic conversion of natural gas into hydrogen and carbon is thermodynamically favorable under atmospheric conditions. However, using noble metals as a catalyst is costly for hydrogen production, thus mandating non-noble metal-based catalysts such as Ni, Co, and Cu-based alloys. This paper reviews the various hydrogen production methods from fossil fuels through pyrolysis, partial oxidation, autothermal, and steam reforming, emphasizing the catalytic production of hydrogen via steam reforming of methane. The multicomponent catalysts composed of several nonnoble materials have been summarized. Of the Ni, Co, and Cu-based catalysts investigated in the literature, Ni/Al2O3 catalyst is the most economical and performs best because it suppresses the coke formation on the catalyst. To avoid carbon emission, this method of hydrogen production from methane should be integrated with carbon capture, utilization, and storage (CCUS). Carbon capture can be accomplished by absorption, adsorption, and membrane separation processes. The remaining challenges, prospects, and future research and development directions are described.
PubDate: 2023-08-20
DOI: 10.1007/s11708-023-0886-4
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