| 1. |
- 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.
|
|
| 2. |
- 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.
|
|
| 3. |
- 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.
|
|
| 4. |
- Hu, Haiman, et al.
(författare)
-
Revealing the role and working mechanism of confined ionic liquids in solid polymer composite electrolytes
- 2024
-
Ingår i: Journal of Energy Chemistry. - : Elsevier. - 2095-4956 .- 2096-885X. ; 99, s. 110-119
-
Tidskriftsartikel (refereegranskat)abstract
- The confined ionic liquid (IL) in solid polymer composite electrolytes (SCPEs) can improve the performance of lithium metal batteries. However, the impact/role and working mechanism of confined IL in SCPEs remain ambiguous. Herein, IL was immobilized on SiO2 (SiO2@IL-C) and then used to prepare the confined SCPEs together with LiTFSI and PEO to study the impacts of confined-IL on the properties and performance of electrolytes and reveal the Li+ transport mechanism. The results show that, compared to the IL-unconfined SCPE, the IL-confined ones exhibit better performance of electrolytes and cells, such as higher ionic conductivity, higher tLi+, and wider electrochemical windows, as well as more stable cycle performance, due to the increased dissociation degree of lithium salt and enlarged polymer amorphousness. The finite-element/molecular-dynamics simulations suggest that the IL confined on the SiO2 provided an additional Li+ transport pathway (Li+ → SiO2@IL-C) that can accelerate ion transfer and alleviate lithium dendrites, leading to ultrastable stripping/plating cycling over 1900 h for the Li/SCPEs/Li symmetric cells. This study demonstrates that IL-confinement is an effective strategy for the intelligent approach of high-performance lithium metal batteries.
|
|
| 5. |
- 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.
|
|
| 6. |
- Jian, Jinpeng, et al.
(författare)
-
Enhancing Li-S battery performance via functional polymer binders for polysulfide inhibition
- 2024
-
Ingår i: Journal of Energy Chemistry. - : Elsevier. - 2095-4956 .- 2096-885X. ; 97, s. 228-236
-
Tidskriftsartikel (refereegranskat)abstract
- The commercialization of lithium -sulfur (Li -S) batteries faces several challenges, including poor conductivity, unexpected volume expansion, and continuous sulfur loss from the cathode due to redox shuttling. In this study, we introduce a novel polymer via a simple cross -linking between poly(ether-thioureas) (PETU) and poly(3,4-ethylenedioxythiophene)- poly(styrenesulfonate) (PEDOT:PSS) as a bifunctional binder for Li -S batteries (devotes as "PPTU"). Compared to polyvinylidene fluoride (PVDF), as -prepared PPTU exhibits significantly higher electrical conductivity, facilitating electrochemical reactions. Additionally, PPTU demonstrates effective adsorption of lithium polysulfides, leading to improved cycling stability by suppressing the shuttling effect. We investigate this behavior by monitoring morphological changes at the cell interface using synchrotron X-ray tomography. Cells with PPTU binders exhibit remarkable rate performance, desired reversibility, and excellent cycling stability even under stringent bending and twisting conditions. Our work represents promising progress in functional polymer binder development for Li -S batteries. (c) 2024 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
|
|
| 7. |
- 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%.
|
|
| 8. |
- 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.
|
|
| 9. |
- 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.
|
|
| 10. |
|
|
