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1.	Cai, Bin, et al. (författare) High isotropic dispiro structure hole transporting materials for planar perovskite solar cells 2019 Ingår i: Journal of Energy Challenges and Mechanics. - : Elsevier. - 2056-9386. ; 32, s. 152-158 Tidskriftsartikel (refereegranskat)abstract Two novel fluorene-based hole transporting materials (HTMs) were synthesized to be used in perovskite solar cells (PSCs). C102 was designed based on C101 by simply linking the two carbon-carbon single bonds to compose a "dispiro" structure. Their typically similar structures cause them sharing almost the same energy levels. However, their photovoltaic performances are quite different due to the small variations. The PSC that contained the "dispiro" structure, C102, reached a power conversion efficiency (PCE) of 17.4%, while the device contained C101, obtained a lower PCE of 15.5%. Electrochemical properties and Photovoltaic characterization of the two materials have been investigated to explain the result. It is shown that C102 has a stronger ability to transport holes and resist the charge recombination. Thus, the dispiro structure should be more appropriate being used as HTM in PSCs. Physics, Chinese Academy of Sciences.
2.	Chang, Qingyan, et al. (författare) Precursor engineering enables high-performance all-inorganic CsPbIBr2 perovskite solar cells with a record efficiency approaching 13% 2024 Ingår i: Journal of Energy Chemistry. - : Elsevier BV. - 2095-4956 .- 2096-885X. ; 90, s. 16-22 Tidskriftsartikel (refereegranskat)abstract All-inorganic CsPbIBr2 perovskite has attracted widespread attention in photovoltaic and other optoelectronic devices because of its superior thermal stability. However, the deposition of high-quality solution-processed CsPbIBr2 perovskite films with large thicknesses remains challenging. Here, we develop a triple-component precursor (TCP) by employing lead bromide, lead iodide, and cesium bromide, to replace the most commonly used double-component precursor (DCP) consisting of lead bromide and cesium iodide. Remarkably, the TCP system significantly increases the solution concentration to 1.3 M, leading to a larger film thickness (∼390 nm) and enhanced light absorption. The resultant CsPbIBr2 films were evaluated in planar n-i-p structured solar cells, which exhibit a considerably higher optimal photocurrent density of 11.50 mA cm−2 in comparison to that of DCP-based devices (10.69 mA cm−2). By adopting an organic surface passivator, the maximum device efficiency using TCP is further boosted to a record efficiency of 12.8% for CsPbIBr2 perovskite solar cells.
3.	Chen, Yuqing, et al. (författare) A review of lithium-ion battery safety concerns : the issues, strategies, and testing standards 2021 Ingår i: Journal of Energy Chemistry. - : Elsevier. - 2095-4956 .- 2096-885X. ; 59, s. 83-99 Tidskriftsartikel (refereegranskat)abstract Efficient and reliable energy storage systems are crucial for our modern society. Lithium-ion batteries (LIBs) with excellent performance are widely used in portable electronics and electric vehicles (EVs), but frequent fires and explosions limit their further and more widespread applications. This review summarizes aspects of LIB safety and discusses the related issues, strategies, and testing standards. Specifically, it begins with a brief introduction to LIB working principles and cell structures, and then provides an overview of the notorious thermal runaway, with an emphasis on the effects of mechanical, electrical, and thermal abuse. The following sections examine strategies for improving cell safety, including approaches through cell chemistry, cooling, and balancing, afterwards describing current safety standards and corresponding tests. The review concludes with insights into potential future developments and the prospects for safer LIBs.
4.	Cheng, Ming, et al. (författare) A novel phenoxazine-based hole transport material for efficient perovskite solar cell 2015 Ingår i: Journal of Energy Challenges and Mechanics. - : Elsevier. - 2056-9386. ; 24:6, s. 698-706 Tidskriftsartikel (refereegranskat)abstract Based on the previous research work in our laboratory, we have designed and synthesized a small-molecule, hole transport material (HTM) POZ6-2 using phenoxazine (POZ) as central unit and dicyanovinyl units as electron-withdrawing terminal groups. Through the introduction of a 2-ethyl-hexyl bulky chain into the POZ core unit, POZ6-2 exhibits good solubility in organic solvents. In addition, POZ6-2 possesses appropriate energy levels in combination with a high hole mobility and conductivity in its pristine form. Therefore, it can readily be used as a dopant-free HTM in perovskite solar cells (PSCs) and a conversion efficiency of 10.3% was obtained. The conductivity of the POZ6-2 layer can be markedly enhanced via doping in combination with typical additives, such as 4-tert-butylpyridine (TBP) and lithium bis(trifluoromethanesulfonyl) imide (LiTFSI). Correspondingly, the efficiency of the PSCs was further improved to 12.3% using doping strategies. Under the same conditions, reference devices based on the well-known HTM Spiro-OMeTAD show an efficiency of 12.8%.
5.	Choi, Seung Young, et al. (författare) Ex situ aging effect on sulfonated poly(ether ether ketone) membrane : Hydration-dehydration cycling and hydrothermal treatment 2022 Ingår i: Journal of Energy Chemistry. - : Elsevier BV. - 2095-4956. ; 70, s. 583-592 Tidskriftsartikel (refereegranskat)abstract Prolonged hydrothermal treatment for sulfonated poly(ether ether ketone) membranes induces mechanical degradation and developing hydrophilic-hydrophobic phase separation, simultaneously. The enhanced phase separation provides incremental proton conductivity to the membranes, whereas mechanical degradation drastically reduces device stability. On this basis, we describe here the effects of two different ex situ aging processes on sulfonated poly(ether ether ketone) membranes: hydration-dehydration cycling and prolonged hydrothermal treatment. Both aged membranes exhibited enhanced phase separation under the hydrated conditions, as characterized by small angle X-ray scattering. However, when the aged membranes were dried again, the nanostructure of the membranes aged via the hydration-dehydration cycling was recoverable, whereas that of the membranes aged via prolonged hydrothermal treatment was irreversible. Furthermore, the two differently aged membranes showed clear differences in thermal, mechanical, and electrochemical properties. Finally, we implemented both aged membranes in fuel cell application. The sample aged via hydration-dehydration cycling maintained its improved cell performance, whereas the sample aged via hydrothermal treatment showed drastically reduced cell performance after durability test for 50 h.
6.	Enterria, Marina, et al. (författare) Driving the sodium-oxygen battery chemistry towards the efficient formation of discharge products : The importance of sodium superoxide quantification 2022 Ingår i: Journal of Energy Challenges and Mechanics. - : Elsevier. - 2056-9386. ; 68, s. 709-720 Tidskriftsartikel (refereegranskat)abstract Sodium-oxygen batteries (SOBs) have the potential to provide energy densities higher than the state-of the-art Li-ion batteries. However, controlling the formation of sodium superoxide (NaO2) as the sole discharge product on the cathode side is crucial to achieve durable and efficient SOBs. In this work, the discharge efficiency of two graphene-based cathodes was evaluated and compared with that of a commercial gas diffusion layer. The discharge products formed at the surface of these cathodes in a glyme-based electrolyte were carefully studied using a range of characterization techniques. NaO(2 )was detected as the main discharge product regardless of the specific cathode material while small amounts of Na2O2 center dot & nbsp;2H(2)O and carbonate-like side-products were detected by X-ray diffraction as well as by Raman and infrared spectroscopies. This work leverages the use of X-ray diffraction to determine the actual yield of NaO2 which is usually overlooked in this type of batteries. Thus, the proper quantification of the superoxide formed on the cathode surface is widely underestimated; even though is crucial for determining the efficiency of the battery while eliminating the parasitic chemistry in SOBs. Here, we develop an ex-situ analysis method to determine the amount of NaO2 generated upon discharge in SOBs by transmission X-ray diffraction and quantitative Rietveld analysis. This work unveils that the yield of NaO(2 )depends on the depth of discharge where high capacities lead to very low discharge efficiency, regardless of the used cathode. We anticipate that the methodology developed herein will provide a convenient diagnosis tool in future efforts to optimize the performance of the different cell components in SOBs. (C)& nbsp;2021 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press.& nbsp;
7.	Etman, Ahmed S., et al. (författare) V2O5·nH2O nanosheets and multi-walled carbon nanotube composite as a negative electrode for sodium-ion batteries 2019 Ingår i: Journal of Energy Chemistry. - : Elsevier BV. - 2095-4956 .- 2096-885X. ; 30, s. 145-151 Tidskriftsartikel (refereegranskat)abstract Two dimensional (2D) transition metal oxides and chalcogenides demonstrate a promising performance in sodium-ion batteries (SIBs) application. In this study, we investigated the use of a composite of freeze dried V2O5·nH2O nanosheets and multi-walled carbon nanotube (MWCNT) as a negative electrode material for SIBs. Cyclic voltammetry (CV) results indicated that a reversible sodium-ion insertion/deinsertion into the composite electrode can be obtained in the potential window of 0.1–2.5 V vs. Na+/Na. The composite electrodes delivered sodium storage capacities of 140 and 45 mAh g−1 under applied current densities of 20 and 100 mA g−1, respectively. The pause test during constant current measurement showed a raise in the open circuit potential (OCP) of about 0.46 V, and a charge capacity loss of ∼10%. These values are comparable with those reported for hard carbon electrodes. For comparison, electrodes of freeze dried V2O5·nH2O nanosheets were prepared and tested for SIBs application. The results showed that the MWCNT plays a significant role in the electrochemical performance of the composite material.
8.	Ghorbani Shiraz, Hamid, et al. (författare) Towards electrochemical hydrogen storage in liquid organic hydrogen carriers via proton-coupled electron transfers 2022 Ingår i: Journal of Energy Challenges and Mechanics. - : Elsevier. - 2056-9386. ; 73, s. 292-300 Tidskriftsartikel (refereegranskat)abstract Green hydrogen is identified as one of the prime clean energy carriers due to its high energy density and a zero emission of CO2. A possible solution for the transport of H2 in a safe and low-cost way is in the form of liquid organic hydrogen carriers (LOHCs). As an alternative to loading LOHC with H2 via a two-step procedure involving preliminary electrolytic production of H2 and subsequent chemical hydrogenation of the LOHC, we explore here the possibility of electrochemical hydrogen storage (EHS) via conversion of proton of a proton donor into a hydrogen atom involved in covalent bonds with the LOHC (R) via a protoncoupled electron transfer (PCET) reaction: . We chose 9-fluorenone/ fluorenol (Fnone/Fnol) conversion as such a model PCET reaction. The electrochemical activation of Fnone via two sequential electron transfers was monitored with in-situ and operando spectroscopies in absence and in presence of different alcohols as proton donors of different reactivity, which enabled us to both quantify and get the mechanistic insight on PCET. The possibility of hydrogen extraction from the loaded carrier molecule was illustrated by chemical activation.
9.	Guo, Yu, et al. (författare) Necessity of structural rearrangements for O[sbnd]O bond formation between O5 and W2 in photosystem II 2021 Ingår i: Journal of Energy Challenges and Mechanics. - : Elsevier B.V.. - 2056-9386. ; 57, s. 436-442 Tidskriftsartikel (refereegranskat)abstract Numerous aspects of the water oxidation mechanism in photosystem II have not been fully elucidated, especially the O[sbnd]O bond formation pathway. However, a body of experimental evidences have identified the O5 and W2 ligands of the oxygen-evolving complex as the highly probable substrate candidates. In this work, we studied O[sbnd]O bond formation between O5 and W2 based on the native Mn4Ca cluster by density functional calculations. Structural rearrangements before the formation of the S4 state were found as a prerequisite for O[sbnd]O bond formation between O5 and W2, regardless if the suggested pathways involving the typical Mn1(IV)-O[rad] species or the recently proposed Mn4(VII)(O)2 species. Possible alternatives for the S2 → S3 and S3 → S4 transitions accounting for such required rearrangements are discussed. These findings reflect that the structural flexibility of the Mn4Ca cluster is essential to allow structural rearrangements during the catalytic cycle.
10.	Islavath, Nanaji, et al. (författare) Effect of hole-transporting materials on the photovoltaic performance and stability of all-ambient-processed perovskite solar cells 2017 Ingår i: Journal of Energy Chemistry. - : Elsevier BV. - 2095-4956 .- 2096-885X. ; 26:3, s. 584-591 Tidskriftsartikel (refereegranskat)abstract High-efficiency perovskite solar cells (PSCs) reported hitherto have been mostly prepared in a moisture and oxygen-free glove-box atmosphere, which hampers upscaling and real-time performance assessment of this exciting photovoltaic technology. In this work, we have systematically studied the feasibility of all-ambient-processing of PSCs and evaluated their photovoltaic performance. It has been shown that phase-pure crystalline tetragonal MAPbI3 perovskite films are instantly formed in ambient air at room temperature by a two-step spin coating process, undermining the need for dry atmosphere and post-annealing. All-ambient-processed PSCs with a configuration of FTO/TiO2/MAPbI3/Spiro-OMeTAD/Au achieve open-circuit voltage (990 mV) and short-circuit current density (20.31 mA/cm2) comparable to those of best reported glove-box processed devices. Nevertheless, device power conversion efficiency is still constrained at 5% by the unusually low fill-factor of 0.25. Dark current–voltage characteristics reveal poor conductivity of hole-transporting layer caused by lack of oxidized spiro-OMeTAD species, resulting in high series-resistance and decreased fill-factor. The study also establishes that the above limitations can be readily overcome by employing an inorganic p-type semiconductor, copper thiocyanate, as ambient-processable hole-transporting layer to yield a fill-factor of 0.54 and a power conversion efficiency of 7.19%. The present findings can have important implications in industrially viable fabrication of large-area PSCs.The poor conductivity of ambient-processed spiro-OMeTAD HTM layer caused by lack of oxidation is identified as a major performance limiting factor and successfully overcome by replacing with stable inorganic CuSCN.
11.	Jiao, Xingxing, et al. (författare) Viability of all-solid-state lithium metal battery coupled with oxide solid-state electrolyte and high-capacity cathode 2024 Ingår i: Journal of Energy Chemistry. - 2095-4956. ; 91, s. 122-131 Tidskriftsartikel (refereegranskat)abstract Owing to the utilization of lithium metal as anode with the ultrahigh theoretical capacity density of 3860 mA h g−1 and oxide-based ceramic solid-state electrolytes (SE), e.g., garnet-type Li7La3Zr2O12 (LLZO), all-state-state lithium metal batteries (ASLMBs) have been widely accepted as the promising alternatives for providing the satisfactory energy density and safety. However, its applications are still challenged by plenty of technical and scientific issues. In this contribution, the co-sintering temperature at 500 °C is proved as a compromise method to fabricate the composite cathode with structural integrity and declined capacity fading of LiNi0.5Co0.2Mn0.3O2 (NCM). On the other hand, it tends to form weaker grain boundary (GB) inside polycrystalline LLZO at inadequate sintering temperature for LLZO, which can induce the intergranular failure of SE during the growth of Li filament inside the unavoidable defect on the interface of SE. Therefore, increasing the strength of GB, refining the grain to 0.4 μm, and precluding the interfacial defect are suggested to postpone the electro-chemo-mechanical failure of SE with weak GB. Moreover, the advanced sintering techniques to lower the co-sintering temperature for both NCM-LLZO composite cathode and LLZO SE can be posted out to realize the viability of state-of-the-art ASLMBs with higher energy density as well as the guaranteed safety.
12.	Kang, Yuqiong, et al. (författare) Phosphorus-doped lithium- and manganese-rich layered oxide cathode material for fast charging lithium-ion batteries 2021 Ingår i: Journal of Energy Chemistry. - : Elsevier. - 2095-4956 .- 2096-885X. ; 62, s. 538-545 Tidskriftsartikel (refereegranskat)abstract Owing to their high theoretical specific capacity and low cost, lithium- and manganese-rich layered oxide (LMR) cathode materials are receiving increasing attention for application in lithium-ion batteries. However, poor lithium ion and electron transport kinetics plus side effects of anion and cation redox reactions hamper power performance and stability of the LMRs. In this study, LMR Li1.2Mn0.6Ni0.2O2 was modified by phosphorus (P)-doping to increase Li+ conductivity in the bulk material. This was achieved by increasing the interlayer spacing of the lithium layer, electron transport and structural stability, resulting in improvement of the rate and safety performance. P5+ doping increased the distance between the (003) crystal planes from ∼0.474 nm to 0.488 nm and enhanced the structural stability by forming strong covalent bonds with oxygen atoms, resulting in an improved rate performance (capacity retention from 38% to 50% at 0.05 C to 5 C) and thermal stability (50% heat release compared with pristine material). First-principles calculations showed the P-doping makes the transfer of excited electrons from the valence band to conduction band easier and P can form a strong covalent bond helping to stabilize material structure. Furthermore, the solid-state electrolyte modified P5+ doped LMR showed an improved cycle performance for up to 200 cycles with capacity retention of 90.5% and enhanced initial coulombic efficiency from 68.5% (pristine) or 81.7% (P-doped LMR) to 88.7%.
13.	Kanninen, Petri, et al. (författare) Activation of commercial Pt/C catalyst toward glucose electro-oxidation by irreversible Bi adsorption 2018 Ingår i: Journal of Energy Challenges and Mechanics. - : Elsevier. - 2056-9386. ; 27:5, s. 1446-1452 Tidskriftsartikel (refereegranskat)abstract The effect of irreversibly adsorbed Bi on commercial Pt/C catalyst toward glucose electro-oxidation reaction (GOR) in different electrolytes (acidic, neutral, alkaline) is studied. Bi is successfully deposited on Pt/C from Bi3+ containing acidic solution from 0 to 90% coverage degree. The stability of the Bi layer in acid and alkaline corresponded to previous studies and started to dissolve at 0.7 V and 0.8 V versus reversible hydrogen electrode (RHE), respectively. However, in neutral phosphate buffer the layer showed remarkable stability to at least 1.2 V versus RHE. Bi modification at low (20%) and high (80%) coverage showed the highest increase in the activity of Pt/C toward GOR by a factor up to 7 due to the increased poisoning resistance of the modified catalyst. The effect of poisoning was especially reduced at high Bi coverage (80%), which shows that adsorbate blocked by Bi through the third-body effect is effective. Finally, with or without Bi modification GOR on Pt/C was most active in alkaline conditions.
14.	Khan, Inayat Ali, et al. (författare) Effect of structural variation in biomass-derived nonfluorinated ionic liquids electrolytes on the performance of supercapacitors 2022 Ingår i: Journal of Energy Chemistry. - : Elsevier. - 2095-4956 .- 2096-885X. ; 69, s. 174-184 Tidskriftsartikel (refereegranskat)abstract There is a growing interest in sustainable and high performance supercapacitors (SCs) operating at elevated temperatures as they are highly demanded in heat-durable electronics. Here, we present a biomass-derived nonfluorinated ionic liquid (IL) [P4444][HFuA] and its structural analogue [P4444][TpA] as electrolytes for supercapacitors comprising multiwall carbon nanotubes and activated charcoal (MWCNTs/AC) mixed carbon composite electrodes. A detailed investigation of the effect of scan rate, temperature, potential window and orientation of ions on the electrodes surfaces is performed. The supercapacitors exhibited relatively lower specific capacitance for both [P4444][HFuA] and [P4444][TpA] ILs at room temperature. However, the specific capacitance has significantly increased with an increase in temperature and potential window. The equivalent serie resistances of the SCs is deceased with increasing temperatures, which is a result of improved ionic conductivities of the IL electrolytes. In CV cycling at 60 °C, the capacitor with [P4444][HFuA] IL-based electrolyte retained about 90% of its initial capacitance, while the capacitor with [P4444][TpA] IL-based electrolyte retained about 83% of its initial capacitance. Atomistic computations revealed that the aromatic [FuA]− and [TpA]− anions displayed perpendicular distribution that can effectively neutralize charges on the carbon surfaces. However, the [HFuA]− anion exhibited somewhat tilted configurations on the carbon electrode surfaces, contributing to their outstanding capacitive performance in electrochemical devices.
15.	Li, Yingzheng, et al. (författare) Influence of O-O formation pathways and charge transfer mediator on lipid bilayer membrane-like photoanodes for water oxidation 2024 Ingår i: Journal of Energy Chemistry. - : Elsevier. - 2095-4956 .- 2096-885X. ; 93, s. 526-537 Tidskriftsartikel (refereegranskat)abstract Inspired by the function of crucial components in photosystem II (PSII), electrochemical and dyesensitized photoelectrochemical (DSPEC) water oxidation devices were constructed by the selfassembly of well-designed amphipathic Ru(bda)-based catalysts (bda = 2,2'-bipyrdine-6,6'-dicarbonoxyl acid) and aliphatic chain decorated electrode surfaces, forming lipid bilayer membrane (LBM)-like structures. The Ru(bda) catalysts on electrode-supported LBM films demonstrated remarkable water oxidation performance with different O-O formation mechanisms. However, compared to the slow charge transfer process, the O-O formation pathways did not determine the PEC water oxidation efficiency of the dyesensitized photoanodes, and the different reaction rates for similar catalysts with different catalytic paths did not determine the PEC performance of the DSPECs. Instead, charge transfer plays a decisive role in the PEC water oxidation rate. When an indolo[3,2-b] carbazole derivative was introduced between the Ru (bda) catalysts and aliphatic chain-modified photosensitizer in LBM films, serving as a charge transfer mediator for the tyrosine-histidine pair in PSII, the PEC water oxidation performance of the corresponding photoanodes was dramatically enhanced.
16.	Liu, Qi, et al. (författare) Surface passivation and hole extraction : Bifunctional interfacial engineering toward high-performance all-inorganic CsPbIBr2 perovskite solar cells with efficiency exceeding 12% 2022 Ingår i: Journal of Energy Challenges and Mechanics. - : Elsevier BV. - 2056-9386. ; 74, s. 387-393 Tidskriftsartikel (refereegranskat)abstract All-inorganic CsPbIBr2 perovskite solar cells (PSCs) have attracted considerable research attention in recent years due to their excellent thermal stability. However, their power conversion efficiencies (PCEs) are relatively low and still far below the theoretical limit. Here, we report the use of an organic dye molecule (namely VG1-C8) as a bifunctional interlayer between perovskite and the hole-transport layer in CsPbIBr2 PSCs. Combined experimental and theoretical calculation results disclose that the mul-tiple Lewis base sites in VG1-C8 can effectively passivate the trap states on the perovskite films. Meanwhile, the p-conjugated dye molecule significantly accelerates the hole extraction from the per-ovskite absorber as evidenced by the photoluminescence analysis. Consequently, the VG1-C8 treatment simultaneously boosts the photovoltage and photocurrent density values from 1.26 V and 10.80 mA cm -2 to 1.31 V and 12.44 mA cm -2, respectively. This leads to a significant enhancement of PCE from 9.20% to 12.10% under one sun irradiation (AM 1.5G). To our knowledge, this is the record efficiency reported so far for CsPbIBr2 PSCs. Thus, the present work demonstrates an effective interfacial passivation strategy for the development of highly efficient PSCs.
17.	Liu, Tianqi, et al. (författare) The future challenges in molecular water oxidation catalysts 2022 Ingår i: Journal of Energy Chemistry. - : Elsevier BV. - 2095-4956 .- 2096-885X. ; 73, s. 643-645 Tidskriftsartikel (refereegranskat)
18.	Milikić, J., et al. (författare) A Pt/MnV2O6 nanocomposite for the borohydride oxidation reaction 2021 Ingår i: Journal of Energy Challenges and Mechanics. - : Elsevier B.V.. - 2056-9386. ; 55, s. 428-436 Tidskriftsartikel (refereegranskat)abstract Problems associated with carbon support corrosion under operating fuel cell conditions require the identification of alternative supports for platinum-based nanosized electrocatalysts. Platinum supported on manganese vanadate (Pt/MnV2O6) was prepared by microwave irradiation method and characterized using X-ray diffraction, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy with energy dispersive spectroscopy, and transmission electron microscopy. The borohydride oxidation reaction (BOR) on Pt/MnV2O6 was studied in highly alkaline media using voltammetry, chronoamperometry, and electrochemical impedance spectroscopy. BOR electrocatalytic activity of Pt/MnV2O6 was also compared with that of commercial Pt/C (46 wt% Pt) electrocatalyst. The apparent activation energy of BOR at Pt/MnV2O6 was estimated to be 32 kJ mol−1 and the order of reaction to be 0.51, indicating that borohydride hydrolysis proceeds in parallel with its oxidation. Long-term stability of Pt/MnV2O6 under BOR typical conditions was observed. A laboratory-scale direct borohydride fuel cell assembled with a Pt/MnV2O6 anode reached a specific power of 274 W g−1. Experimental results on Pt/MnV2O6 were complemented by DFT calculations, which indicated good adherence of Pt to MnV2O6, beneficial for electrocatalyst stability.
19.	Nie, Zhicheng, et al. (författare) Reversed charge transfer induced by nickel in Fe-Ni/Mo2C@nitrogen-doped carbon nanobox for promoted reversible oxygen electrocatalysis 2024 Ingår i: Journal of Energy Chemistry. - : Elsevier. - 2095-4956 .- 2096-885X. ; 88, s. 202-212 Tidskriftsartikel (refereegranskat)abstract The interaction between metal and support is critical in oxygen catalysis as it governs the charge transfer between these two entities, influences the electronic structures of the supported metal, affects the adsorption energies of reaction intermediates, and ultimately impacts the catalytic performance. In this study, we discovered a unique charge transfer reversal phenomenon in a metal/carbon nanohybrid system. Specifically, electrons were transferred from the metal-based species to N-doped carbon, while the carbon support reciprocally donated electrons to the metal domain upon the introduction of nickel. This led to the exceptional electrocatalytic performances of the resulting Ni-Fe/Mo2C@nitrogen-doped carbon catalyst, with a half-wave potential of 0.91 V towards oxygen reduction reaction (ORR) and a low overpotential of 290 mV at 10 mA cm−2 towards oxygen evolution reaction (OER) under alkaline conditions. Additionally, the Fe-Ni/Mo2C@carbon heterojunction catalyst demonstrated high specific capacity (794 mA h gZn−1) and excellent cycling stability (200 h) in a Zn-air battery. Theoretical calculations revealed that Mo2C effectively inhibited charge transfer from Fe to the support, while secondary doping of Ni induced a charge transfer reversal, resulting in electron accumulation in the Fe-Ni alloy region. This local electronic structure modulation significantly reduced energy barriers in the oxygen catalysis process, enhancing the catalytic efficiency of both ORR and OER. Consequently, our findings underscore the potential of manipulating charge transfer reversal between the metal and support as a promising strategy for developing highly-active and durable bi-functional oxygen electrodes.
20.	Ojagh, Houman, 1976, et al. (författare) The effect of rosin acid on hydrodeoxygenation of fatty acid 2019 Ingår i: Journal of Energy Chemistry. - : Elsevier BV. - 2095-4956. ; 28, s. 85-94 Tidskriftsartikel (refereegranskat)abstract In this study, inhibition of tall oil fatty acid hydrodeoxygenation (HDO) activity due to addition of rosin acid over sulfided NiMo/Al2O3 was investigated. Oleic acid and abietic acid were used as model compounds for fatty acid and rosin acid respectively in tall oil. After completion of each HDO experiment, the NiMo catalysts were recovered and used again under the same conditions. The results showed that the oleic acid HDO activity of sulfided catalysts was inhibited by addition of abietic acid due to competitive adsorption and increased coke deposition. The rate of carbon deposition on the catalysts increased when abietic acid was added to oleic acid feed. Moreover, the coke was in a more advanced form with higher stability for the catalysts exposed to both oleic acid and abietic acid. Furthermore, a clear correlation between the rate of coke formation and concentration of abietic acid was observed.
21.	Qiao, Mengfei, et al. (författare) Ni-Co bimetallic coordination effect for long lifetime rechargeable Zn-air battery 2020 Ingår i: Journal of Energy Challenges and Mechanics. - : Elsevier. - 2056-9386. ; 47, s. 146-154 Tidskriftsartikel (refereegranskat)abstract The development of bifunctional oxygen electrocatalysts with high efficiency, high stability, and low cost is of great significance to the industrialization of rechargeable Zn–air batteries. A widely accepted view is that the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) follow different catalytic mechanisms, and accordingly they need different active sites for catalysis. Transition metal elements have admirable electronic acceptance ability for coordinating with reactants, and this can weaken the bond energy between reactants, thus promoting the ORR or OER reactions. Herein, the ORR and OER activities of different transition metal supported nitrogen-doped carbon nanotubes were systematically studied and compared. The optimal catalyst for synchronous ORR and OER was obtained by pyrolyzing melamine, cobalt nitrate, and nickel nitrate on carbon nanotubes, called cobalt–nickel supported nitrogen-mixed carbon nanotubes (CoNi–NCNT), which were equipped with two types of high-performance active sites—the Co/Ni–N–C structure for the ORR and CoNi alloy particles for the OER—simultaneously. Remarkably, the optimized CoNi–NCNT exhibited a satisfactory bifunctional catalytic activity for both the ORR and OER. The value of the oxygen electrode activity parameter, ΔE, of CoNi–NCNT was 0.81 V, which surpasses that of catalysts Pt/C and Ir/C, and most of the non-precious metal-based bifunctional electrocatalysts reported in previous literatures. Furthermore, a specially assembled rechargeable Zn–air cell with CoNi–NCNT loaded carbon paper as an air cathode was used to evaluate the practicability. As a result, a superior specific capacity of 744.3 mAh/gZn, a peak power density of 88 mW/cm2, and an excellent rechargeable cycling stability were observed, and these endow the CoNi–NCNT with promising prospects for practical application.
22.	Shahid, Bilal, et al. (författare) Low-bandgap polymers with quinoid unit as π bridge for high-performance solar cells 2020 Ingår i: Journal of Energy Chemistry. - : Elsevier BV. - 2095-4956. ; 40:2020, s. 180-187 Tidskriftsartikel (refereegranskat)abstract To construct efficient low band gap polymers, increasing the Quinone structure of the polymer backbone could be one desirable strategy. In this work, two D–Q–A–Q polymers P1 and P2 were designed and synthesized with thiophenopyrrole diketone (TPD) and benzothiadiazole (BT) unit as the core and ester linked thieno[3,4-b]thiophene (TT) segment as π-bridging, and the main focus is to make a comparative analysis of different cores in the influence of the optical, electrochemical, photochemical and morphological properties. Compared with the reported PBDTT EH –TBTT HD−i , P1 exhibited the decreased HOMO energy level of −5.38 eV and lower bandgap of 1.48 eV. Furthermore, when replaced with BT core, P2 showed a red-shifted absorption profile of polymer but with up-shifted HOMO energy level. When fabricated the photovoltaic devices in conventional structure, just as expected, the introduction of ester substituent made an obvious increase of V OC from 0.63 to 0.74 V for P1. Besides, due to the deep HOMO energy level, higher hole mobility and excellent phase separation with PC 71 BM, a superior photovoltaic performance (PCE = 7.13%) was obtained with a short-circuit current density (J SC ) of 14.9 mA/cm 2 , significantly higher than that of P2 (PCE = 2.23%). Generally, this study highlights that the strategy of inserting quinoid moieties into D–A polymers could be optional in LBG-polymers design and presents the importance and comparison of potentially competent core groups.
23.	Wan, X., et al. (författare) Efficient and stable planar all-inorganic perovskite solar cells based on high-quality CsPbBr3 films with controllable morphology 2020 Ingår i: Journal of Energy Challenges and Mechanics. - : Elsevier. - 2056-9386. ; 46, s. 8-15 Tidskriftsartikel (refereegranskat)abstract All-inorganic cesium lead bromide (CsPbBr3) perovskite is attracting growing interest as functional materials in photovoltaics and other optoelectronic devices due to its superb stability. However, the fabrication of high-quality CsPbBr3 films still remains a big challenge by solution-process because of the low solubility of the cesium precursor in common solvents. Herein, we report a facile solution-processed approach to prepare high-quality CsPbBr3 perovskite films via a two-step spin-coating method, in which the CsBr methanol/H2O mixed solvent solution is spin-coated onto the lead bromide films, followed by an isopropanol-assisted post-treatment to regulate the crystallization process and to control the film morphology. In this fashion, dense and uniform CsPbBr3 films are obtained consisting of large crystalline domains with sizes up to microns and low defect density. The effectiveness of the resulting CsPbBr3 films is further examined in perovskite solar cells (PSCs) with a simplified planar architecture of fluorine‒doped tin oxide/compact TiO2/CsPbBr3/carbon, which deliver a maximum power conversion efficiency of 8.11% together with excellent thermal and humidity stability. The present work offers a simple and effective strategy in fabrication of high-quality CsPbBr3 films for efficient and stable PSCs as well as other optoelectronic devices.
24.	Wang, Linqin, et al. (författare) A crosslinked polymer as dopant-free hole-transport material for efficient n-i-p type perovskite solar cells 2021 Ingår i: Journal of Energy Chemistry. - : Elsevier BV. - 2095-4956 .- 2096-885X. ; 55, s. 211-218 Tidskriftsartikel (refereegranskat)abstract A new crosslinked polymer, called P65, with appropriate photo-electrochemical, opto-electronic, and thermal properties, has been designed and synthesized as an efficient, dopant-free, hole-transport material (HTM) for n-i-p type planar perovskite solar cells (PSCs). P65 is obtained from a low-cost and easily synthesized spiro[fluorene-9,9′-xanthene]-3′,6′-diol (SFX-OH)-based monomer X65 through a free-radical polymerization reaction. The combination of a three-dimensional (3D) SFX core unit, hole-transport methoxydiphenylamine group, and crosslinked polyvinyl network provides P65 with good solubility and excellent film-forming properties. By employing P65 as a dopant-free hole-transport layer in conventional n-i-p type PSCs, a power conversion efficiency (PCE) of up to 17.7% is achieved. To the best of our knowledge, this is the first time a 3D, crosslinked, polymeric dopant-free HTM has been reported for use in conventional n-i-p type PSCs. This study provides a new strategy for the future development of a 3D crosslinked polymeric dopant-free HTM with a simple synthetic route and low-cost for commercial, large-scale applications in future PSCs.
25.	Wang, Xianshu, et al. (författare) Non-solvating fluorosulfonyl carboxylate enables temperature-tolerant lithium metal batteries 2023 Ingår i: Journal of Energy Chemistry. - : Elsevier. - 2095-4956 .- 2096-885X. ; 82, s. 287-295 Tidskriftsartikel (refereegranskat)abstract Advanced electrolyte engineering is an important strategy for developing high-efficacy lithium (Li) metal batteries (LMBs). Unfortunately, the current electrolytes limit the scope for creating batteries that perform well over temperature ranges. Here, we present a new electrolyte design that uses fluorosulfonyl carboxylate as a non-solvating solvent to form difluoroxalate borate (DFOB-) anion-rich solvation sheath, to realize high-performance working of temperature-tolerant LMBs. With this optimized electrolyte, favorable SEI and CEI chemistries on Li metal anode and nickel-rich cathode are achieved, respectively, leading to fast Li+ transfer kinetics, dendrite-free Li deposition and suppressed electrolyte deterioration. Therefore, Li\|\|LiNi0.80Co0.15Al0.05O2 batteries with a thin Li foil (50 μm) show a long-term cycling lifespan over 400 cycles at 1 C and a superior capacity retention of 90% after 200 cycles at 0.5 C under 25 ℃. Moreover, this electrolyte extends the operating temperature from -10 to 30 ℃ and significantly improve the capacity retention and Coulombic efficiency of batteries are improved at high temperature (60 ℃). Fluorosulfonyl carboxylates thus have considerable potential for use in high-performance and all-weather LMBs, which broadens the new exploring of electrolyte design.
26.	Wang, Y., et al. (författare) Inherent mass transfer engineering of a Co, N co-doped carbon material towards oxygen reduction reaction 2021 Ingår i: Journal of Energy Challenges and Mechanics. - : Elsevier BV. - 2056-9386. ; 58, s. 391-396 Tidskriftsartikel (refereegranskat)abstract Current concerns on material-design induced mass transfer processes during small molecule electrocatalysis are on the ones assisted by external forced convection generally via electrode rotating, demonstrating the intrinsic activity of catalysts. Of note is that, in practical battery configurations, there is no the forced convection around electrode micro-environments. Therefore, the establishment of effective strategies in tuning the inherent mass transfer process, the one with no assistance by external forced convection, is also greatly significant, but rarely reported, retarding further advances. Herein, a size-induced inherent mass-transfer strategy is scrupulously established through designed kinetic investigations and also controllable construction of uniform Co, N co-doped carbon materials with a wide range of tunable particle sizes from 10 nm to 2 μm. The catalysts are synthesized by a pyrolysis of zeolitic imidazolate framework (ZIF) 67@ZIF-8, in which the wrapped shell layer avoids evident metal aggregations, and also contributes to rich porous environments after carbonizations. It is unclosed that particle size has a considerable effect on inherent mass transfer processes, even for the porous carbon catalysts. A particle size at around 700 nm is revealed to be most favorable for the inherent mass transfer process within the probed range, revealed by the smallest difference of Tafel slopes obtained with no electrode rotation and with infinite rotation speed. The latter is achieved via extrapolating rotation speeds to infinity in the Koutecký-Levich plots, by which the external mass transfer limitation can be completely eliminated. Contributed by the great inherent mass transfer process, the catalyst with a particle size of around 700 nm exhibits an impressive ORR activity in both three-electrode systems and zinc-air batteries. This work not only establishes a novel strategy in tuning inherent mass transfer process for small molecule electrocatalysis, more importantly, it provides a new dimension in kinetic investigations and oriented design of advanced energy materials.
27.	Wen, Tian-Jiao, et al. (författare) Non-fused medium bandgap electron acceptors for efficient organic photovoltaics 2022 Ingår i: Journal of Energy Challenges and Mechanics. - : ELSEVIER. - 2056-9386. ; 70, s. 576-582 Tidskriftsartikel (refereegranskat)abstract The cost-effective organic semiconductors are strongly needed in organic photovoltaics (OPVs). Herein, two medium bandgap (MBG) electron acceptors, TPT4F and TPT4Cl are developed via the new design of multi-noncovalent interaction assisted unfused core, flanked with two electron withdrawing end groups. These fullly non-fused MBG acceptors adapt the planar and rigid conformation in solid, therefore exhibiting the ordered face-on stacking and strong photoluminescence in films. As results, TPT4Cl-based OPVs, upon blending with the PBDB-TF polymer donor, have achieved a power conversion efficiency of 10.16% with a low non-radiative loss of 0.27 eV, representing one of the best fullly non-fused medium bandgap acceptors with desirable cost-efficiency balance. (c) 2022 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.
28.	Wu, Tai, et al. (författare) Highly stable perovskite solar cells with a novel Ni-based metal organic complex as dopant-free hole-transporting material 2022 Ingår i: Journal of Energy Challenges and Mechanics. - : Elsevier BV. - 2056-9386. ; 65, s. 312-318 Tidskriftsartikel (refereegranskat)abstract Hole-transporting material (HTM) plays a paramount role in enhancing the photovltaic performance of perovskite solar cells (PSCs). Currently, the vast majority of these HTMs employed in PSCs are organic small molecules and polymers, yet the use of organic metal complexes in PSCs applications remains less explored. To date, most of reported HTMs require additional chemical additives (e.g. Li-TFSI, t-TBP) towards high performance, however, the introduction of additives decrease the PSCs device stability. Herein, an organic metal complex (Ni-TPA) is first developed as a dopant-free HTM applied in PSCs for its facile synthesis and efficient hole extract/transfer ability. Consequently, the dopant-free Ni-TPAbased device achieves a champion efficiency of 17.89%, which is superior to that of pristine SpiroOMeTAD (14.25%). Furthermore, we introduce a double HTM layer with a graded energy bandgap containing a Ni-TPA layer and a CuSCN layer into PSCs, the non-encapsulated PSCs based on the Ni-TPA/ CuSCN layers affords impressive efficiency up to 20.39% and maintains 96% of the initial PCE after 1000 h at a relative humidity around 40%. The results have demonstrated that metal organic complexes represent a great promise for designing new dopant-free HTMs towards highly stable PSCs.
29.	Xie, Kunpeng, 1985, et al. (författare) A reevaluation of the correlation between the synthesis parameters and structure and properties of nitrogen-doped carbon nanotubes 2015 Ingår i: Journal of Energy Chemistry. - : Elsevier BV. - 2095-4956. ; 24:4, s. 407-415 Tidskriftsartikel (refereegranskat)abstract Nitrogen-doped carbon nanotubes (NCNTs) were synthesized by chemical vapor deposition using cobalt-based oxides as catalyst and ethylenediamine (EDA) as carbon/nitrogen precursor. The influence of growth time, EDA concentration and growth temperature on the morphology, yield, composition, graphitization and oxidation resistance of the NCNTs was systematically investigated by using Raman spectroscopy, temperature-programmed oxidation and other techniques. The NCNT growth from ethylenediamine with a high N/C ratio involves several processes including mainly (1) catalytic growth of NCNTs, (2) homogeneous gas-phase decomposition of EDA, (3) non-catalytic deposition of pyrolytic carbon/nitrogen species and (4) surface etching of amorphous carbon or carbon at defect sites through gasification. At a later growth stage the etching process appears to be dominating, leading to the thinning of nanotubes and the decrease of yield. Moreover, the surface etching through carbon gasification strongly influences the structure and degree of graphitization of NCNTs.
30.	Xie, Kunpeng, 1985, et al. (författare) Promoting effect of nitrogen doping on carbon nanotube-supported RuO2 applied in the electrocatalytic oxygen evolution reaction 2016 Ingår i: Journal of Energy Chemistry. - : Elsevier BV. - 2095-4956. ; 25:2, s. 282-288 Tidskriftsartikel (refereegranskat)abstract RuO2 nanoparticles supported on multi-walled carbon nanotubes (CNTs) functionalized with oxygen (OCNTs) and nitrogen (NCNTs) were employed for the oxygen evolution reaction (OER) in 0.1 M KOH. The catalysts were synthesized by metal-organic chemical vapor deposition using ruthenium carbonyl (Ru3(CO)12) as Ru precursor. The obtained RuO2/OCNT and RuO2/NCNT composites were characterized using TEM, H2-TPR, XRD and XPS in order probe structure-activity correlations, particularly, the effect of the different surface functional groups on the electrochemical OER performance. The electrocatalytic activity and stability of the catalysts with mean RuO2 particle sizes of 13-14 nm was evaluated by linear sweep voltammetry, cyclic voltammetry, and chronopotentiometry, showing that the generation of nitrogen-containing functional groups on CNTs was beneficial for both OER activity and stability. In the presence of RuO2, carbon corrosion was found to be significantly less severe.
31.	Xiong, Shaobing, et al. (författare) Defect passivation by nontoxic biomaterial yields 21% efficiency perovskite solar cells 2021 Ingår i: Journal of Energy Challenges and Mechanics. - : ELSEVIER. - 2056-9386. ; 55, s. 265-271 Tidskriftsartikel (refereegranskat)abstract Defect passivation is one of the most important strategies to boost both the efficiency and stability of perovskite solar cells (PSCs). Here, nontoxic and sustainable forest-based biomaterial, betulin, is first introduced into perovskites. The experiments and calculations reveal that betulin can effectively passivate the uncoordinated lead ions in perovskites via sharing the lone pair electrons of hydroxyl group, promoting charge transport. As a result, the power conversion efficiencies of the p-i-n planar PSCs remarkably increase from 19.14% to 21.15%, with the improvement of other parameters. The hydrogen bonds of betulin lock methylamine and halogen ions along the grain boundaries and on the film surface and thus suppress ion migration, further stabilizing perovskite crystal structures. These positive effects enable the PSCs to maintain 90% of the initial efficiency after 30 days in ambient air with 60%+/- 5% relative humidity, 75% after 300 h aging at 85 degrees C, and 55% after 250 h light soaking, respectively. This work opens a new pathway for using nontoxic and low-cost biomaterials from forest to make highly efficient and stable PSCs. (C) 2020 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.
32.	Yao, Ya'nan, et al. (författare) Highly efficient photocatalytic reduction of CO2 and H2O to CO and H-2 with a cobalt bipyridyl complex 2018 Ingår i: Journal of Energy Challenges and Mechanics. - : ELSEVIER SCIENCE BV. - 2056-9386. ; 27:2, s. 502-506 Tidskriftsartikel (refereegranskat)abstract The development of efficient molecular catalysts for visible-light driven CO2 reduction, based on abundant materials, is necessary to meet energy demands and address environment problems. In this work, a Co(bpy)(2)Cl-2 catalyst was developed and showed high efficiency and durability for the photocatalytic reduction of CO2 and protons. Yields of CO and H-2 as high as 62.3 and 69.9 mu mol were achieved and the turnover numbers (TONs) reached 6230 and 6990, respectively, under light irradiation (lambda > 420 nm) for 4 h, indicating that the mixture gases could be a candidate as syngas. The apparent quantum yield was determined to be 2.1% for CO. Mechanistic studies revealed oxidative quenching of the photosensitizer Ru(bpy)(3)Cl-2 by the catalyst. The photocatalytic performance, flexible synthesis and non-noble metal catalyst in our system show great promise for the practical application of Co(bpy)(2)Cl-2 to photocatalytic reduction of CO2.
33.	Yin, Zhengzhi, et al. (författare) Electrochemical deposited amorphous FeNi hydroxide electrode for oxygen evolution reaction 2022 Ingår i: Journal of Energy Chemistry. - : Elsevier. - 2095-4956 .- 2096-885X. ; 69, s. 585-592 Tidskriftsartikel (refereegranskat)abstract The electrodeposition approach is significant in electrode fabrication for practical application. Herein, the electrodeposited amorphous NiFe hydroxide species for oxygen evolution reaction (OER) in water splitting reaction is demonstrated by revealing the synergistic effect influenced by the support electrode of Fe and Ni foil and the contents of Fe and Ni in the electrolyte. All the electrodeposited samples have an amorphous structure and similar profiles of binding energy and chemical states for Fe and Ni as characterized by the spectroscopic techniques. While the support effect and Fe/Ni synergistic effect are indeed observed for the varied catalytic performances observed for the different electrodes; the Ni foil supported catalyst exhibits much higher performance than that of the Fe foil supported catalyst, and the different redox potentials of Ni species in the different Fe/Ni electrode resulting from the Fe–Ni synergism are observed in the cyclic voltammetry curve analysis. The surface roughness and the electrochemical surface area are also influenced by the support effect and the Fe/Ni ratio in the plating electrolyte. The optimal electrode shows a very low overpotential of ∼200 mV to reach 10 mA cm−2, and very high catalytic stability by the consecutive cyclic voltammetry measurements and 20 h stability test. Though it has the largest electrochemical surface area, the highest catalytic efficiency for these active sites is also indicated by the specific activity and turnover frequency polarization curves. The current work shows the effective experience for the electrodeposited Fe/Ni based catalysts in large-scale fabrication, which can be more practical for hydrogen generation in the alkaline water electrolysis.
34.	Zhang, Biaobiao, et al. (författare) Switching O–O bond formation mechanism between WNA and I2M pathways by modifying the Ru-bda backbone ligands of water-oxidation catalysts 2021 Ingår i: Journal of Energy Challenges and Mechanics. - : Elsevier B.V.. - 2056-9386. ; 54, s. 815-821 Tidskriftsartikel (refereegranskat)abstract Understanding the seven coordination and O–O coupling pathway of the distinguished Ru-bda catalysts is essential for the development of next generation efficient water-oxidation catalysts based on earth-abundant metals. This work reports the synthesis, characterization and catalytic properties of a monomeric ruthenium catalyst Ru-bnda (H2bnda = 2,2′-bi(nicotinic acid)-6,6′-dicarboxylic acid) featuring steric hindrance and enhanced hydrophilicity on the backbone. Combining experimental evidence with systematic density functional theory calculations on the Ru-bnda and related catalysts Ru-bda (H2bda = 2,2ʹ-bipyridine-6,6ʹ-dicarboxylic acid), Ru-pda (H2pda = 1,10-phenanthroline-2,9-dicarboxylic acid), and Ru-biqa (H2biqa = (1,1ʹ-biisoquinoline)-3,3ʹ-dicarboxylic acid), we emphasized that seven coordination clearly determines presence of RuV[dbnd]O with high spin density on the ORuV[dbnd]O atom, i.e. oxo with radical properties, which is one of the necessary conditions for reacting through the O–O coupling pathway. However, an additional factor to make the condition sufficient is the favorable intermolecular face-to-face interaction for the generation of the pre-reactive [RuV[dbnd]O···O[dbnd]RuV], which may be significantly influenced by the secondary coordination environments. This work provides a new understanding of the structure–activity relationship of water-oxidation catalysts and their potential to adopt I2M pathway for O–O bond formation.
35.	Zhang, Shu, et al. (författare) Mitigating the Jahn-Teller distortion driven by the spin-orbit coupling of lithium manganate cathode 2022 Ingår i: Journal of Energy Challenges and Mechanics. - : Elsevier BV. - 2056-9386. ; 72, s. 379-387 Tidskriftsartikel (refereegranskat)abstract Spinel LiMn2O4 is recognized as one of the most competitive cathode candidates for lithium-ion batteries ascribed to environmentally benign and rich sources. However, the wholesale application of LiMn2O4 is predominately plagued by its severe capacity degradation, mainly associated with the innate Jahn-Teller effect. Herein, single-crystalline LiMn2O4 with Eu3+ doping is rationally designed to mitigate the detrimental Jahn-Teller distortion by tuning the chemical environment of MnO6 octahedra and accommodating localized electron, based on the unique aspheric flexible 4f electron orbit of rare-earth metal ions. Notably, the stretching of MnO6 octahedron stemmed from the Jahn-Teller effect in Eu-doped LiMn2O4 is effectively suppressed, confirmed by theoretical calculation. Meanwhile, the structural stability of the material has been significantly enhanced due to the robust Mn–O band coherency and weakened phase transition, proved by synchrotron radiation absorption spectrum and operando X-ray diffraction. The corresponding active cathode manifests superior long-cycle stability after 300 loops at 2C and displays only a 0.011% capacity drop per cycle even at 5C. Given this, this modification tactic sheds new light on achieving superior long-cycle performances by suppressing distortion in various cathode materials.
36.	Zhang, Yanyun, et al. (författare) DDQ as an effective p-type dopant for the hole-transport material X1 and its application in stable solid-state dye-sensitized solar cells 2018 Ingår i: Journal of Energy Challenges and Mechanics. - : ELSEVIER SCIENCE BV. - 2056-9386. ; 27:2, s. 413-418 Tidskriftsartikel (refereegranskat)abstract X1 (MeO-TPD) is an inexpensive and easily synthesized pi-conjugated molecule that has been used as a hole-transport material (HTM) in solid-state dye-sensitized solar cells (ssDSSCs), achieving relatively high efficiency. In this paper, we characterize the physicochemical properties of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and show that it is a promising p-dopant in a spin-coating solution with X1 as the HTM. The doped ssDSSCs showed an increase in short-circuit current density from 5.38 mA cm(-2) to 7.39 mA cm(-2), and their overall power conversion efficiency increased from 2.9% to 4.3%. Also, ssDSSCs with DDQ-doped X1 were more stable than the undoped samples, demonstrating that DDQ can act as a p-type dopant in X1 as an HTM for highly efficient, stable ssDSSCs.
37.	Zhao, Dan, et al. (författare) Ionic thermoelectric materials and devices 2021 Ingår i: Journal of Energy Challenges and Mechanics. - : ELSEVIER. - 2056-9386. ; 61, s. 88-103 Forskningsöversikt (refereegranskat)abstract The tremendous amount of wasted heat from solar radiation and industry dissipation has motivated the development of thermoelectric concepts that directly convert heat into electricity. The main challenge in practical applications for thermoelectrics is the high cost from both materials and manufacturing. Recently, breakthrough progresses in ionic thermoelectrics open up new possibilities to charge energy storage devices when submitted to a temperature gradient. The charging voltage is internally from the ionic Seebeck effect of the electrolyte between two electrodes. Hence electrolytes with high thermoelectric figure of merit are classified as ionic thermoelectric materials. Most ionic thermoelectric materials are composed of abundant elements, and they can generate hundreds of times larger thermal voltage than that of electronic materials. This emerging thermoelectric category brings new hope to fabricate low cost and large area heat-to-energy conversion devices, and triggers a renewed interest for ionic thermodiffusion. In this review, we summarize the state of the art in the new field of ionic thermoelectrics, from the driving force of the ionic thermodiffusion to material and application developments. We present a general map of ionic thermoelectric materials, discuss the unique characters of each type of the reported electrolytes, and propose potential optimization and future topics of ionic thermoelectrics. (c) 2021 The Authors. Published by ELSEVIER B.V. and Science Press on behalf of Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

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