Elemental sulfur cathodes for lithium/sulfur batteries are receiving intense interest owing to their high theoretical capacity and energy density. However, they still suffer from severe capacity ...fading and moderate rate capability. Herein, we provide rational design and controllable fabrication of highly uniform flower-like hierarchical carbon nanospheres (FCNS) for sulfur accommodation for lithium/sulfur battery cathodes. The as-prepared three dimension FCNS with a size of around 200 nm seem to be assembled by petal-like carbon nanosheets with a thickness of about 4 nm, forming many mesoporous channels, which lead to their high surface area and large pore volume. With such a tailor-made structure, FCNS/sulfur composite cathodes with high sulfur-loading (81 wt%) deliver high specific capacity, long cycling life and excellent rate capability. Particularly, N-doped flower-like carbon nanospheres (NFCNS) with higher surface area (1223 m2 g-1) and larger pore volume (2.33 cm3 g-1) are also fabricated by treating with NH3 and used to host sulfur in lithium-sulfur battery cathodes, exhibiting more excellent rate capability (829 mA h g-1 at 5C) and cycling stability with a decay of 0.03% per cycle over 200 cycles at 1C. Even though the area density is improved to 2.5 mg sulfur per cm2, the battery still has a decay of 0.056% per cycle over 200 cycles.
Reported herein is the investigation of a unique cathode candidate for Li–S batteries, i.e. Ni 3 S 2 /(N, S)-RGO-type hybrid materials, which are expected to optimize battery performance by elevating ...the utilization of sulfur and chemically confining the adsorption/diffusion of polysulfide. Versatile structural and compositional characterizations confirmed the uniform growth and strong chemical coupling of nanostructured Ni 3 S 2 on the N/S co-doped RGO matrix. Rich physical and chemical properties were revealed, namely, the large specific surface area and pore volume, which are beneficial for polysulfide capture, and the 3D conductive network supporting rapid charge transfer to the Ni 3 S 2 -polysulfide interface to improve the intrinsic equilibrium of the polysulfide. Specifically, the integration of ∼28.2 wt% of Ni 3 S 2 produced a highly pleated composite with the largest BET specific surface area (618 m 2 g −1 ) and pore volume (1.73 cm 3 g −1 ) among the hybrids studied. This typical material also performed the best in the battery test, recording ultra-high cycling stability over 1000 cycles at the current density of 3C with the capacity decay of 0.023% per cycle. As the sulfur loading per unit area became as dense as 5.8 mg cm −2 , the specific capacities were measured as 6.72 mA h cm −2 (at 0.05C), while the capacity retention for the 200-cycle test (at 1C) was still preserved above 72.5%.
Reported herein is the investigation of a unique cathode candidate for Li-S batteries,
i.e.
Ni
3
S
2
/(N, S)-RGO-type hybrid materials, which are expected to optimize battery performance by elevating ...the utilization of sulfur and chemically confining the adsorption/diffusion of polysulfide. Versatile structural and compositional characterizations confirmed the uniform growth and strong chemical coupling of nanostructured Ni
3
S
2
on the N/S co-doped RGO matrix. Rich physical and chemical properties were revealed, namely, the large specific surface area and pore volume, which are beneficial for polysulfide capture, and the 3D conductive network supporting rapid charge transfer to the Ni
3
S
2
-polysulfide interface to improve the intrinsic equilibrium of the polysulfide. Specifically, the integration of ∼28.2 wt% of Ni
3
S
2
produced a highly pleated composite with the largest BET specific surface area (618 m
2
g
−1
) and pore volume (1.73 cm
3
g
−1
) among the hybrids studied. This typical material also performed the best in the battery test, recording ultra-high cycling stability over 1000 cycles at the current density of 3C with the capacity decay of 0.023% per cycle. As the sulfur loading per unit area became as dense as 5.8 mg cm
−2
, the specific capacities were measured as 6.72 mA h cm
−2
(at 0.05C), while the capacity retention for the 200-cycle test (at 1C) was still preserved above 72.5%.
As a sulfur host for the lithium-sulfur battery, Ni
3
S
2
anchored to N/S co-doped RGO with a highly pleated structure has demonstrated the strong capture of polysulfides, exhibiting high reversible capacity and cycling stability.
Abstract
Lithium metal anode (LMA) is the next generation of high‐performance electrochemical energy storage materials because of its unique advantages (high capacity and low redox potential). ...However, a discontinuous solid electrolyte interface (SEI) layer and lithium dendrites are formed during battery charging, leading to serious safety problems. For this purpose, researchers have devised many solutions, such as artificial SEI, modified current collector, and lithium alloy layer. Among them, the three‐dimensional (3D) current collector with a high surface area can not only reduce the local current density of lithium deposition but also promote lithium‐ion transfer and nucleation, thus inhibiting dendrite growth. In this progress report, we review the design of the LMA 3D‐structured current collector in accordance with the classification. Firstly, we discuss the latest development of advanced metal current collectors. Secondly, the 3D design of carbon‐based current collectors is summarized to improve the overall performance of lithium metal batteries (LMBs). Finally, the main challenges and development prospects of LMBs’ current collectors in the future are discussed.
As an all-inorganic zero-dimensional (0D) lead-free metal halide, Cs 2 ZnCl 4 is a potentially excellent matrix for preparing chemically stable and environmentally friendly photoluminescent materials ...through an ion-doping strategy. Therefore, it is necessary to study the emission properties of every kind of doping ion in the tetrahedral coordination of Cs 2 ZnCl 4 . Here, for the first time, we successfully synthesized Te 4+ -doped Cs 2 ZnCl 4 single crystals via a facile hydrothermal method. X-ray crystallography clearly reveals the strong distortion of the tetrahedral units in Cs 2 ZnCl 4 caused by doping with Te 4+ . Broadband yellow-light emission covering the range from 450 nm to 700 nm with a large Stokes shift is observed in Cs 2 ZnCl 4 :Te 4+ single crystals, and this is attributed to self-trapped excitons (STEs) caused by the lattice vibration of the distorted structure. It is worth mentioning that this broadband yellow phosphor can be excited by a wide range of blue light, implicitly giving it an excellent ability to adapt to multiple models of blue LED chips, thus serving as a suitable yellow phosphor that can be applied to fabricate WLEDs without the need to worry about the lack of red light.
As an all-inorganic zero-dimensional (0D) lead-free metal halide, Cs
2
ZnCl
4
is a potentially excellent matrix for preparing chemically stable and environmentally friendly photoluminescent materials ...through an ion-doping strategy. Therefore, it is necessary to study the emission properties of every kind of doping ion in the tetrahedral coordination of Cs
2
ZnCl
4
. Here, for the first time, we successfully synthesized Te
4+
-doped Cs
2
ZnCl
4
single crystals
via
a facile hydrothermal method. X-ray crystallography clearly reveals the strong distortion of the tetrahedral units in Cs
2
ZnCl
4
caused by doping with Te
4+
. Broadband yellow-light emission covering the range from 450 nm to 700 nm with a large Stokes shift is observed in Cs
2
ZnCl
4
:Te
4+
single crystals, and this is attributed to self-trapped excitons (STEs) caused by the lattice vibration of the distorted structure. It is worth mentioning that this broadband yellow phosphor can be excited by a wide range of blue light, implicitly giving it an excellent ability to adapt to multiple models of blue LED chips, thus serving as a suitable yellow phosphor that can be applied to fabricate WLEDs without the need to worry about the lack of red light.
Bright broadband yellow light emission peaking at 570 nm has been successfully obtained
via
incorporating Te
4+
ions into Cs
2
ZnCl
4
single crystals, and this is attributed to self-trapped exciton (STE) emission from the distorted tetrahedral units.
Abstract
High entropy alloys (HEAs) are composed of five or more metal elements with similar proportions. Due to the electronic structure among metal elements, they have abundant active sites and ...have good catalytic activity and stability as materials. Therefore, they have great promise in electrochemical energy storage and electrocatalysis. This paper reviews the preparation and characterization methods of HEAs, and the applications of HEAs in catalysis, especially the contribution in lithium‐sulfur batteries, but also in Electrolyzed water and other energy storage materials. The challenges of HEAs in catalysis and their future developments are also presented.
Compared with freshwater resources, seawater is cheaper and more abundant. However, the abundance of chloride ions in seawater affects the oxygen evolution reaction at the anode, and thus it is ...necessary to develop efficient oxygen-producing anode catalysts for direct electrolytic seawater splitting. Among the numerous anode catalysts, non-noble metal materials have prime industrial application prospects due to their easy availability and low price. Thus, to grasp the current research status of non-noble metal electrocatalysts used in the electrolysis of direct seawater splitting anodes, herein we classify these catalyst materials and summarize them based on three aspects.
i.e.
, structural analysis, mechanism research, and application conditions. Firstly, we analyze the mechanism of the chlorine evolution reaction and oxygen evolution reaction in seawater and the competitive relationship between them. Subsequently, based on the functional types of non-noble metal anode catalysts, they are divided into high-selectivity catalysts and chloride ion barrier layer catalysts. Also, we present certain experimental methods to evaluate the high-selectivity efficiency of anode catalysts for reference. Finally, the existing problems associated with anodic electrocatalysts for seawater cracking are elaborated and their future development directions are prospected.
Herein, we review the current status of selective seawater oxidation based on four aspects, including competition of the reactions, mechanism analysis, catalyst classification, and evaluation of catalyst efficiency.
Lithium/sodium‐based batteries have attracted widespread attention because of their high specific capacity and excellent energy density, and have become one of the hottest research directions in ...energy storage devices. However, the stress accumulated during the continuous electrochemical cycle will cause the inevitable electrode failure, which inhibits the further improvement of battery performance. In order to eliminate/relieve the internal stress problem, a variety of battery material structures have been designed. In the design of battery material structure, the simulation technology is used to conduct battery modeling to predict the experimental results, which effectively reduces the range of parameters. For this reason, this paper first introduces the parameters that need to be considered by establishing stress model. Then, the utilization of simulation technology in the structural design of diverse battery materials is examined in this study. Finally, the future application of simulation technology in the field of energy storage is prospected. This is aimed to encourage the widespread utilization of simulation technology in the energy storage battery industry, with the goal of reducing design‐related energy consumption, enhancing experimental design feasibility, and minimizing experimentation costs.
The review introduces the parameters that need to be considered for the construction of stress models in the field of batteries, and explores the practical application of stress relief in different structures such as porous, core‐shell, and heterogeneous structures by using a synergistic approach of simulation techniques and experimental analyses.
Nitrogen-doped porous carbon plates have been prepared by simple and cost-effective pyrolysis carbonization of an easily available biomass-fallen camellia flower and followed by alkali activation. ...As-prepared nitrogen-doped porous carbon (aNPCP3) possesses a high specific surface area of 2318 m
2
g
−1
and abundant micro/meso-pores. As a result, the aNPCP3 samples have been demonstrated to be electrodes for supercapacitors, displaying a high specific capacitance of 354 F g
−1
at a current density of 0.2 A g
−1
and excellent cycling stability. Further, the aNPCP3 samples used as sulfur host materials for lithium-sulfur batteries exhibit a high capacity of 1210 mAh g
−1
and good cycling stability with a small capacity decay of about 0.1 % per cycle. Interestingly, it is found that their electrochemical performances are dependent on their specific surface area, pore structure, and heteroatom-doping content and type of carbon materials to a large extent. Cheapness, convenient resource, and good performance make these electrode materials displaying huge potential in cost-effective high-performance energy storage devices.
