Search

Flexible energy storage devices with high energy density and excellent mechanical properties have attracted great interest in the development of flexible electrodes. However, flexible electrodes don't have current collectors, limiting their battery performance. To improve the performance of flexible electrodes, a cobalt-based (Co-based) current collector was designed and fabricated. It is proved that the Co-based current collector is promising due to high conductivity, light weight, continuity and close contact with the electrode. Meanwhile, when the Co-based current collector is applied in lithium–sulfur batteries, it can physically and chemically restrict polysulfides and inhibit the shuttle effect. As a result, Li–S batteries assembled with Co modified electrodes deliver a specific discharge capacity of 899 mA h g−1 at 1C. And a high reversible capacity of 639 mA h g−1 and capacity retention of 56.1% can also be achieved at 0.1C even after continuously running for 200 cycles with a high sulfur loading of 8 mg cm−2. [ABSTRACT FROM AUTHOR]

Realizing decarbonization and sustainable energy supply by the integration of variable renewable energies has become an important direction for energy development. Flow batteries (FBs) are currently one of the most promising technologies for large-scale energy storage. This review aims to provide a comprehensive analysis of the state-of-the-art progress in FBs from the new perspectives of technological and environmental sustainability, thus guiding the future development of FB technologies. More importantly, we evaluate the current situation and future development of key materials with key aspects of green economy and decarbonization to promote sustainable development and improve the novel energy framework. Finally, we present an analysis of the current challenges and prospects on how to effectively construct low-carbon and sustainable FB materials in the future. [ABSTRACT FROM AUTHOR]

2-Thiobenzazole is among the privileged heterocyclic scaffolds in medicinal chemistry. Constructing such structural components in DNA-encoded libraries (DELs) may promote related bioactive hit discovery in a high-throughput fashion. Herein, we reported a DNA-compatible mild-condition synthetic methodology to efficiently forge functionalized 2-thiobenzazole scaffolds, realizing on-DNA sulfhydryl incorporation with broad substrate scope, thereby expanding the scope of 2-thiobenzazole-focused DNA-encoded chemical libraries. [ABSTRACT FROM AUTHOR]

White-light emission (WLE) materials based on organic–inorganic hybrid lead halides have drawn considerable attention because of their applications in light-emission equipment. Despite considerable efforts, there is still a lack of two-dimensional (2D) lead-chlorine white-light emitting halides with high photoluminescence quantum efficiency (PLQE). Herein, we report the preparation of a new 2D layered hybrid halide, [DTHPE]Pb4Cl10, which exhibits bright wide-band WLE, a high PLQE of 8.86% and high anti-water stability. To the best of our knowledge, the PLQE of [DTHPE]Pb4Cl10 exceeds that of most 2D lead chlorides. Furthermore, the emission intensity is unchanged even after continuous immersion in water for 7 days. Photoluminescence measurements indicate that the WLE originates from self-trapped excitons. [DTHPE]Pb4Cl10 is a promising visible-blind UV hybrid halide owing to its excellent photoelectric response. [DTHPE]Pb4Cl10 is an effective white-light emitting material for display applications. The coexistence of a high performance visible-blind UV response and high efficiency white-light emission provides attractive possibilities for potential applications in the multifunctional photoelectronic field. [ABSTRACT FROM AUTHOR]

Sb-Doped high-voltage LiCoO2 was developed with unique properties. In situ X-ray diffraction and density functional theory reveal that the introduction of Sb helps to shorten the Li+ diffusion distance, increase the lattice spacing and keep the structural stability during deep lithiation, thus resulting in improved rate capability and cycling performance. [ABSTRACT FROM AUTHOR]

Double perovskite nanocrystals (NCs) have attracted much attention owing to their non-toxicity and excellent semiconducting characteristics. Herein, a series of double perovskite Cs4CuxAg2−2xSb2Cl12 NCs (x = 0.60, 0.75, 0.90, and 1.00) have been synthesized and the relationship between the Cu2+ content and their photo-physical properties has been investigated in detail. The temperature-dependent absorption data point out that the Cu2+ content can affect the transition from the indirect to direct band gap, but hardly influence the evolution of the band edge at different temperatures, which almost linearly red shifts with temperature. The transient absorption technique helps us to obtain the absorption coefficient of these double perovskite NCs. The linear and three-order nonlinear absorption coefficients, which are first measured by transient absorption (TA) and Z-scan techniques, apparently decrease with the Cu2+ content. Intensity-dependent TA curves offer their carrier recombination rate constants (involving the mono-molecular (k1), bi-molecular (k2) and Auger recombination (k3) rate constants). Herein, k1 decreases with the Cu2+ content owing to the variance of Cu–Cl bonds in the x–y plane, but k2 and k3 show an opposite trend. The current–voltage test with strong light bias confirms that the monomolecular recombination is dominant in the operation of photo-detectors based on Cs4CuxAg2−2xSb2Cl12 NC films and the light-harvesting ability should be responsible for the photocurrent of the photo-detector. Our results provide a comprehensive insight into the optoelectronic properties of these double perovskite NCs. [ABSTRACT FROM AUTHOR]

Designing membranes with highly ion-selective conductivity is one of the key questions for the large-scale application of redox flow batteries, which can unlock the potential of the renewable energy industry. The selectivity of ion exchange membranes is usually limited by the larger size of the nanochannels than that of redox-active ions. Herein, sub-1-nanometer channels of membranes were constructed through covalently bonding the polysilsesquioxane nanocages with multiple branched amino groups onto a polymer material. The synergistic effect of super hydrophilicity, extra functional amino groups and matched sub-1-nanometer sieve structure accomplished the sieving of proton to redox-active ions and ensured fast proton conduction. The ultrahigh proton-selective conductivity of 1.18 × 1011 mS s cm−3 enabled high electrochemical performance and surprisingly excellent durability over 7000 cycles (>4000 deep cycles for energy applications) even in the harsh environment of a vanadium flow battery. These results indicated that the new membrane design with multi-scale ion-sieving nanochannels is promising for high-efficiency and durable redox flow batteries. [ABSTRACT FROM AUTHOR]

Vanadium flow batteries (VFBs) are attracting increasing attention due to their promising prospect for large-scale energy storage. However, the high cost and low selectivity of current membranes limit their further application. In this work, a highly conductive (1122 mS cm−1) and stable microporous membrane was obtained via oxidizing a dense anion exchange membrane by an in situ or off situ process. Poly[(fluorene alkylene)-co-(biphenyl alkylene)] (PFBA-QA) with pendant quaternary ammonium alkyl groups was designed and prepared. The difference in stability between the main and side chains of the ether-free polymer allows the transformation of ion channels from aggregated ion clusters in the dense membrane to micropores by sacrificing the side chain in a strong oxidative environment. As a result, a VFB assembled with the resulting membrane demonstrates a CE of 97% and an EE of 88% at a current density of 80 mA cm−2, which can stably run for more than 290 cycles. This paper provides a new option for the membrane design in VFBs. [ABSTRACT FROM AUTHOR]

Zinc–bromine batteries (ZBBs) receive wide attention in distributed energy storage because of the advantages of high theoretical energy density and low cost. However, their large-scale application is still confronted with some obstacles. Therefore, in-depth research and advancement on the structure, electrolyte, anode, cathode and membrane are of great significance and impendency. Herein, we review the past and present investigations on ZBBs, discuss the key problems and technical challenges, and propose perspectives for the future, with the focus on materials and chemistry. This perspective would provide valuable information on further development of ZBBs. [ABSTRACT FROM AUTHOR]

Solvent treatment has been proved to be an effective strategy for the preparation of highly selective porous membranes for flow batteries. Herein, a fast and efficient method to screen suitable solvents to produce high performance porous polybenzimidazole (PBI) membranes was developed by a machine learning (ML) approach for the first time. The polymer–solvent interaction, which affects the final membrane morphologies, was further confirmed by Density Functional Theory (DFT). The predicted performance [voltage efficiency (VE) and energy efficiency (EE)] for a PBI membrane in a vanadium flow battery (VFB) can achieve a mean absolute prediction error (MAPE) within 1%. Based on the coefficients of membrane performance prediction models, solvent properties such as the melting point, heat of evaporation, dipole moment and surface tension exert significant influence on the morphology of PBI membranes and further their cell performance in VFBs. It was proved that alcohols are the most suitable solvents for solvent treatment of porous PBI membranes, due to similar polarity and strong interaction between alcohols and the PBI segment, which was confirmed by DFT calculations. This work provides an efficient methodology to regulate membrane morphologies and presents a concept to reveal the inherent relationship hidden in data mapping. [ABSTRACT FROM AUTHOR]

Manganese-based flow batteries have attracted increasing interest due to their advantages of low cost and high energy density. However, the sediment (MnO2) from Mn3+ disproportionation reaction creates the risk of blocking pipelines, leading to poor stability. Herein, a titanium–manganese single flow battery (TMSFB) with high stability is designed and fabricated for the first time. In the design, a static cathode without the tank and pump is employed to avoid blockage of pipelines by MnO2 particles. Benefiting from the deceasing disproportionation reaction rate, MnO2 from the disproportionation reaction is fully utilized, realizing nearly two electron capacity. The novel TMSFB exhibits coulombic efficiency (CE) of over 99.0% at a current density of 40 mA cm−2. Most importantly, the TMSFB can run stably over 1000 cycles without capacity decay, demonstrating very good stability. With low cost, high efficiency and long cycle life, TMSFBs exhibit remarkable potential for large scale energy storage. [ABSTRACT FROM AUTHOR]

With the excessive consumption of fossil fuels, CO2 emission issues and the energy crisis have become more prominent. The electrocatalytic reduction of CO2 (ERC) driven by intermittent renewable electricity can not only mitigate carbon dioxide emission, but also store renewable energy. However, the poor activity, selectivity and stability of the catalysts inhibit their practical large-scale application. Herein, we report a facile synthesis method for a synthetic N-doped hierarchical porous carbon catalyst, which was obtained by directly carbonizing the ZIF8 precursor decorated with the low boiling metal salts (BiCl3). Plentiful bismuth salts can not only efficiently destroy the Zn–Nx bond and promote the aggregation and evaporation of the Zn species at a relatively low temperature, but also enhance the formation of a conductive and hierarchical porous catalyst. In addition, the tedious post-processing to remove the metal salts is avoided. Density functional theory calculations suggest that the coordinated unsaturated Zn–Nx sites tremendously inhibit the activity of the nearby pyridinic N sites, which play an important role in the catalytic performance. As a result, the catalysts achieve about 90% faradaic efficiency for CO at a very low overpotential of −0.49 V, which is much lower than the most reported N-doped carbon catalysts. [ABSTRACT FROM AUTHOR]

Sodium-ion batteries are considered surrogates for conventional lithium-ion batteries for the commercial sector. One of the most favourable anode materials for sodium-ion batteries is hard carbon. However, its performance is affected by the large irreversible capacity loss (ICL) in the initial charge process. This study proposes the Na4V2(PO4)3 (Na4VP) cathode as a possible solution for matching the hard carbon anode. The process uses a recently developed electrochemical pre-sodiation strategy, where the first step converts Na3V2(PO4)3 (Na3VP) to a Na4VP cathode by a sodiation step. After this, a de-sodiation step of Na4VP is carried out below 2.2 V (vs. Na+/Na) to entirely compensate for the ICL of the anode, and the resulting Na3VP directly acts as the cathode. As a result, the Na4VP‖HC full cell achieves a substantially high specific energy of 265 W h kg−1, which is 76% higher than that of the Na3VP‖HC full cell. Moreover, the Na4VP‖HC full cell shows excellent rate performance (62.32 mA h g−1 at 10C) and cycling stability (about 80.0% capacity retention after 100 cycles at 1C). This work is a precursor to the further study of other battery and hybrid capacitor systems, where pre-sodiation plays an important role in improving their performance. [ABSTRACT FROM AUTHOR]

The development of primary batteries with high energy density, long shelf life, and stable discharge voltage is essential for civilization and military applications. Primary batteries with high power output and excellent low-temperature performance can further broaden their application. Herein, a Li/LiV2(PO4)3 primary battery was proposed and investigated for the first time. In order to improve the shelf life of the Li/LiV2(PO4)3 primary battery, the mechanism and corresponding inhibition strategy of self-discharge were studied in detail. It was found that the electrolyte composition is a key factor affecting the shelf life of Li/LiV2(PO4)3 primary batteries, where the corrosion of aluminum (Al) current collector triggered by the organic radical cations generated from electrochemical oxidation of the ethylene carbonate (EC) at high potential; and the detrimental reaction between LiV2(PO4)3 and electrolyte lead to the self-discharge of the Li/LiV2(PO4)3 primary battery. When the EC solvent was replaced by the propylene carbonate (PC) solvent, the corrosion of Al foil was alleviated. Moreover, the addition of lithium bis(oxalato)borate (LiBOB) to the electrolyte could improve the stability of cathode/electrolyte interface and enhance the shelf life of the Li/LiV2(PO4)3 primary battery. As a result, 100% capacity could be maintained after over one-month storage, 86% energy could be maintained at 50C, and 63% energy could be maintained at −40 °C at a current density of 0.1C. In addition, the Li/LiV2(PO4)3 primary battery showed great potential for all-weather applications. [ABSTRACT FROM AUTHOR]

Rechargeable aqueous zinc ion batteries have attracted significant attention for practical energy storage due to their low cost and high safety, however, it is still a hard task to find suitable cathode materials to meet the demand of both high capacity and rate performance. Here, we propose a high-performance anhydrous V2O5 yolk–shell cathode via a facile template-free solvothermal technique. Owing to its porous structure, the V2O5 cathode could largely facilitate rapid electrolyte transportation and restrain structural collapse during cycling. Moreover, it is interesting to find that the interlayer spacing expands from 4.37 to 13.45 Å through an interesting activation process, as a result, the prepared V2O5 cathode demonstrated high reversible capacities of 410 mA h g−1 at 0.1 A g−1 and 182 mA h g−1 at 20 A g−1 and a capacity retention of 80% can be achieved over 1000 cycles at 5.0 A g−1, which is superior to those of most commonly reported anhydrous V2O5 cathodes. Therefore, this paper demonstrates the potential of V2O5 for achieving high energy/power densities as a cathode material in ZIBs. [ABSTRACT FROM AUTHOR]

One-dimensional (1D) SiC nanostructures have attracted considerable interest owing to their unique structure and excellent performance, but nanostructure entanglement limits their application. In this work, a robust photocatalytic composite SiC@SiO2/carbon nanofiber mat (SiC@CNFMs) is prepared via facile and environmentally friendly blow-spinning (BLS) followed by calcination in absence of metal catalysts. The several hundred micron long as-prepared nanocrystal structures consist of a single-crystalline β-SiC core (diameter between 30–150 nm) and an ultra-thin (8 nm) amorphous SiO2 shell layer. The growth process of the SiC/SiO2 nanofiber is in good agreement with the vapor–solid (VS) mechanism. The synthesized SiC@CNFMs exhibit excellent photodegradation of dyes and due to the utilization of PAN-based carbon nanofiber mats, they show good recycling performance with a dye degradation above 88–95% after 5 cycles. Lastly, the synthesized SiC@CNFMs show high chemical stability under both alkaline and acidic conditions. From these properties, the synthesized SiC@CNFMs show promising potential for wastewater cleaning. [ABSTRACT FROM AUTHOR]

Self-standing electrodes have attracted great attention due to their promising applications in advanced electronic devices with high-energy demands. Inspired by the 3D framework and well-controlled porous structure of the porous membrane prepared via the phase separation method, for the first time, a binder-free 3D porous self-standing electrode has been designed and fabricated by using a porous polybenzimidazole (PBI) membrane as the template. Various methods were investigated in detail, in which the ethanol phase separation-derived method resulted in a sponge-like cross section and porous structure of both surfaces, leading to the best electrochemical performance. Meanwhile, considering the carbon content, the optimized self-standing Na3V2(PO4)3@C electrode exhibited excellent rate performance (110.4 mA h g−1 at 0.5C and 108.1 mA h g−1 at 40C) and cycling stability (capacity retention of 90.4% after 2000 cycles at 1C). The superior electrochemical performance can be ascribed to the high electron conductivity due to the 3D N-doped cross-linked carbon matrix and the fast Na+ diffusion in the spongy macro-porous structure. The self-standing electrode prepared via this method exhibited high flexibility in the electrode mass loading, pore structures (sponge-like, finger-like, etc.) and electrode shapes (fiber, coil, spiral, letter, etc.). This phase separation-derived method will greatly promote the development and large-scale application of self-standing electrodes. [ABSTRACT FROM AUTHOR]

With the explosive growth in intermittent renewable sources and the global drive toward decarbonizing the energy economy, reliable large-scale electrical energy storage technologies with high safety and low cost are urgently needed. Aqueous batteries hold the intrinsic advantages of nonflammability and low cost; the zinc//bromine flow battery and LiMn2O4//NaTi2(PO4)3 aqueous rechargeable ion battery are two representative systems with relatively high voltages (1.6 V to 1.8 V in common aqueous solutions). However, the long-term cycling stability of intercalation/de-intercalation type cathode materials is easily impaired by pH fluctuance, while the deposition/dissolution-type zinc anode suffers from zinc dendrites and uneven deposition issues. To avoid these two issues, we propose a novel bromine//NaTi2(PO4)3 hybrid ion battery, involving an aqueous redox pair (Br3−/Br−, with high reactivity in a pH range from 0 to 9) and a high-loading ion intercalation anode (NaTi2(PO4)3, with low working voltage and little volume change). First, the high-performance NTP@C nanoparticles are synthesized by a modified sol–gel method. Then, the three-dimensional NTP@C anode with super high mass loading is designed by employing a porous and conductive carbon substrate. The crossover of bromine in aqueous catholyte is suppressed by an effective bromine complexing agent and the insufficient ion transport in a thick solid anode is conquered by a negative flowing electrolyte. As a result, the hybrid ion battery shows high areal energy density, high power density and promising cycling stability. The full cell can deliver a high energy density and power density of 12.8 mW h cm−2 (109 W h kg−1 based on NTP@C and reacted LiBr) and 29.4 mW cm−2 (250 W kg−1 based on NTP@C and reacted LiBr), respectively. Moreover, the power density can reach 106 mW cm−2 with energy density remaining at 7.95 mW h cm−2 (68 W h kg−1 based on NTP@C and reacted LiBr) at a super high current density of 100 mA cm−2. An average capacity loss of 0.075% per cycle is obtained during a 200-cycle test, demonstrating the great feasibility of the new system. Therefore, this hybrid battery has great potential in large scale electrical energy storage. [ABSTRACT FROM AUTHOR]

An ultra-high voltage viologen/Br2 flow battery was designed based on a novel two-electron viologen derivative, a highly-conductive and low-cost porous polyolefin membrane, and an effective complexing agent, making the battery one of the most stable two-electron viologen-based flow batteries with superior energy and power density at the same time. [ABSTRACT FROM AUTHOR]

Magnesium ion batteries (MIBs) have attracted significant research attention owing to their low cost, high energy density, and the natural abundance of magnesium. However, lack of compatible cathode materials hinders their further development. Herein, we present a magnesium–lithium hybrid ion battery (MLIB) comprising a Li3V2(PO4)3 (LVP) cathode and magnesium metal anode, where fast reaction kinetics of Li+ ions at the LVP cathode and that of Mg2+ ions at the anode led to high reversible capacities. As a result, a rechargeable MLIB shows excellent rate performance (147.8 and 65.3 mA h g−1 at 50 and 2500 mA g−1 respectively) and capacity retention (99% for 200 cycles), which are the highest values among the reported hybrid batteries using lithium cathodes. To improve temperature adaptability of the designed MLIB, two different kinds of magnesium electrolytes (i.e. all-phenyl-complex and magnesium borohydride in diglyme) and inorganic lithium additives were investigated. It is found that the all-phenyl-complex along with LiCl additives can suppress the freezing of electrolytes effectively even at −40 °C. While, high reversible capacities of 117, 93.4, and 63.1 mA h g−1 can be obtained at 0, −20, and −40 °C respectively, at a current density of 100 mA g−1, showing a very promising prospect for low temperature applications. [ABSTRACT FROM AUTHOR]

The conversion of CO2 into value-added chemicals by employing renewable energy via an electrochemical process has received increasing attention. However, the low reaction rate and efficiency, as well as poor selectivity, have limited its further development. The low solubility of CO2 in an aqueous solution is one of the main factors that limit the reaction rate and selectivity of the electroreduction of CO2 (ERC) at a high overpotential. In this study, an organic additive containing an –NH2 group (methyl carbamate, MC) was incorporated into the ERC electrolyte for the first time. By utilizing the affinity interaction between a Lewis acid (the –NH3+ group formed by protonation of the –NH2 group) and a Lewis base (CO2), the ERC reaction rate was increased by 17%, and the faradaic efficiency for the production of CH4 reached 81.6%, which represented a large increase of 34% and surpassed that of most reported Cu electrodes. Furthermore, the partial current density for the production of CH4 was 31 mA cm−2 at −2.13 V (vs. RHE), which represents an increase of 30% in comparison with that in the blank system. In addition, the competitive hydrogen evolution reaction was substantially inhibited, and the decline in faradaic efficiency increased from 38.5% to 48.1% when the potential decreased gradually from −1.63 V to −1.98 V (vs. RHE). DFT calculations further indicate that the –NH3+ group can significantly promote the adsorption of CO* and CHO* on the Cu surface and increase the surface coverage of both intermediates. CHO* can be further stabilized by the –NH3+ group via the facilitation of partial electron transfer from Cu to C and the formation of H-bonds, which is favorable for further hydrogenation to form hydrocarbons. These results provide a simple and powerful way to increase the reaction rate and product selectivity of the reduction of CO2. [ABSTRACT FROM AUTHOR]

Molybdate polyanion cathode materials have received lots of research interest for their high specific capacity, high cycling stability and interesting physical and chemical properties. Here, LiCr(MoO4)2, a new deintercalation–intercalation type cathode material for lithium ion batteries, is synthesized and studied. Ultraviolet-visible-near-infrared diffuse reflection, density functional theory calculation and four-probe measurement results suggest that LiCr(MoO4)2 possesses a narrow band gap and high electronic conductivity. Bond-valence-sum maps calculation and electrochemical impedance spectroscopy prove the fast lithium ion transport rate of LiCr(MoO4)2. Benefiting from these advantages, LiCr(MoO4)2 delivers a high specific capacity (250 mA h g−1) and good rate performances. The electrochemical reaction mechanism is studied by in situ X-ray diffraction, which indicates that the lithium ion deintercalation–intercalation is a solid solution process with Cr3+/2+ and Mo6+/5+ redox. [ABSTRACT FROM AUTHOR]

A superior monoclinic NaVPO4F nanoplate for Na-ion batteries has been prepared by a molten-state-blending technique. By this molecular level blending method, a nanoscale-laminated NaVPO4F@C sample with high crystallinity can be obtained. High thermal stability, stable Na+ insertion/extraction and superior electron/Na+ transport of NaVPO4F have been elucidated by temperature-dependent IR, in situ XRD and kinetic investigations. Accordingly, the as-prepared NaVPO4F with moderate carbon coating exhibits superior Na-storage performance. It can deliver a high initial specific capacity of 135.0 mA h g−1 at 0.2C, ultra-high rate performance (up to 112.1 mA h g−1 at 30C) and super-stable cycling performance (capacity fading rate of 0.0064% per cycle during 1500 cycles at 20C). The potential application of NaVPO4F as the anode has been explored, and a symmetrical battery with NaVPO4F as both the anode and cathode has been successfully assembled for the first time. More significantly, in situ XRD and ex situ NMR have been employed to explore the charge–discharge behavior in a Na-ion battery, and the result clearly demonstrates that less than one Na has been intercalated/extracted from NaVPO4F during the charging/discharging process. [ABSTRACT FROM AUTHOR]

To obtain a satisfactory rate performance of lithium–sulfur (Li–S) batteries with a high sulfur loading, the vapour induced phase inversion (VIPI) process was used to prepare sponge-like porous electrodes. It is suitable for various solvents, binders and materials on account of phase separation principles and produces electrodes with enhanced adhesive properties, high electrolyte uptake and improved capability in electron/ion transport. As a result, batteries assembled with the VIPIE delivered a high initial discharge capacity of 1171 mA h g−1 and presented a capacity retention of 56.6% within 400 cycles at 0.5C. Additionally, a high discharge capacity of 693 mA h g−1 could be also obtained at 2C due to the facilitated electron/ion transport. An electrode with a high sulfur loading of 19 mg cm−2 could be realized. The 10 mg cm−2 sulfur loaded VIPIE delivered a high capacity of 1300 mA h g−1 at 0.05C (equaling to an areal capacity of 13.0 mA h cm−2) and showed a high capacity retention of 90.7% within 60 cycles at 0.1C. [ABSTRACT FROM AUTHOR]

The rational design of cathode hosts with superior polysulfide (PS) confinement properties, excellent Li+/e− transport and improved cyclability is of the utmost importance for high-areal-capacity lithium–sulfur (Li–S) batteries. Herein, multi-functional nanowall arrays (MNWAs) combining the aforementioned properties are fabricated to improve the electrochemical performance of Li–S batteries with high areal sulfur loadings. The integrated conductive networks and top-down vertically aligned Li+ transport channels are beneficial to Li+/e− transport, resulting in high rate performance with a discharge capacity of 620 mA h g−1 at a high current density of 9.6 mA cm−2 for 4 mg cm−2 sulfur-loaded S/MNWA electrodes. Additionally, the strong PS shuttling suppression via the synergetic effects of physical confinement and chemical adsorption leads to Li–S batteries with a sulfur loading of 10 mg cm−2 capable of delivering a high areal capacity of 12.4 mA h cm−2 with a high capacity retention of nearly 85% for over 100 cycles. What's more, the Li–S batteries assembled with 4 mg cm−2 sulfur-loaded S/MNWA electrodes show an ultra-low capacity decay of 0.07% per cycle over 400 cycles at 3.2 mA cm−2. [ABSTRACT FROM AUTHOR]

Sulfates have long been ignored as nonlinear optical materials over the past decades. Here we report a new sulfate deep-ultraviolet nonlinear optical material Li8NaRb3(SO4)6·2H2O synthesized by the facile water solution method. It crystallizes in the asymmetric monoclinic space group C2 (No. 5). Its single-crystal structure features a three-dimensional framework made up of SO4 and LiO4 tetrahedra. Powder second-harmonic generation tests demonstrate that Li8NaRb3(SO4)6·2H2O is phase-matchable with a second-harmonic generation response of about 0.5 × KH2PO4. Ultraviolet-visible-near-infrared diffuse reflectance spectra illustrate that the ultraviolet cutoff edge of Li8NaRb3(SO4)6·2H2O may be as low as λ ＜ 190 nm. Theoretical calculations reveal that the optical properties of Li8NaRb3(SO4)6·2H2O are mainly attributed to S–O groups. All these results reveal that Li8NaRb3(SO4)6·2H2O may possess potential use in the deep-ultraviolet nonlinear optics field. We believe that the discoveries in our work will attract scientists’ attention to sulfate systems for their potential as deep-ultraviolet nonlinear optical materials. [ABSTRACT FROM AUTHOR]

Molybdate cathode materials have attracted a lot of attention due to their rich crystal structure, stable skeleton structure and moderate electronic conductivity. In this paper, a new NASICON-type material Li3Cr(MoO4) 3 has been studied for the first time as a cathode material for lithium ion batteries with high specific capacity. Comprehensive studies by X-ray diffraction, UV-vis-IR diffuse reflection, bond valence sum maps calculation, cyclic voltammetry, electrochemical impedance spectroscopy and the Four-Probe method show that Li3Cr(MoO4)3 possesses a narrow band gap, high electronic conductivity and fast lithium ion transport channels, and delivers a high specific capacity (200 mA h g−1) and rate performance. Electrochemical mechanism studies indicate that both the Mo6+/5+ and Cr3+/Cr2+ reactions contribute to the high specific capacity. [ABSTRACT FROM AUTHOR]

A new concept of the membrane-free interfacial battery based on a biphasic system was proposed for the first time. An aqueous ZnBr2 solution was used as a negative electrolyte, while Br2 in CCl4 served as a positive electrolyte. This interfacial Zn/Br2 battery demonstrated a very impressive performance with a CE of 96% and an EE of 81% at a current density of 15 mA cm−2. [ABSTRACT FROM AUTHOR]

Solvent treatment has been proved to be a very simple and efficient method to prepare high-performance porous membranes for flow batteries. In this article, the process parameters of solvent treatment were regulated to further investigate the formation mechanism of porous membranes. The effect of the solvent evaporation temperature, the solvent immersion time and the solvent composition on the morphology and performance of porous membranes was studied systematically. The adjustment of these process parameters made the acting mechanisms of the polymer–solvent interaction and the cohesive force of polymers more clear. The factors affecting the polymer–solvent interaction and the cohesive force, along with the acting principles of process parameters, were also elucidated in detail. The formation mechanism of porous membranes during solvent treatment was accordingly clarified distinctly. As a result, an optimized VFB performance of treated membranes with a coulombic efficiency of 98.33%, and an energy efficiency of 81.17% at 160 mA cm−2 was achieved, which was much higher than that of Nafion 115 and among the highest values ever reported. Moreover, this VFB could continually run over 2600 cycles at 200 mA cm−2, without obvious efficiency fade. Thus, this paper provides a simpler, quicker and more economical method to prepare high-performance porous membranes for flow batteries. [ABSTRACT FROM AUTHOR]

Rational molecular structure modification towards high performance redox couples attracts great concern. A ferrocene derivative N-(pyridin-2-ylmethylene)-1-(2-(diphenylphosphino) ferrocenyl) ethanamine (FeCp2PPh2RCN) with improved solubility and potential as well as multi-electron transfer behavior is designed and fabricated. Benefitting from the high operating current density and capacity of the battery, FeCp2PPh2RCN demonstrates promising prospects as a positive redox moiety. [ABSTRACT FROM AUTHOR]

Flow batteries, aqueous flow batteries in particular, are the most promising candidates for stationary energy storage to realize the wide utilization of renewable energy sources. To meet the requirement of large-scale energy storage, there has been a growing interest in aqueous flow batteries, especially in novel redox couples and flow-type systems. However, the development of aqueous flow battery technologies is at an early stage and their performance can be further improved. As a key component of a flow battery, the membrane has a significant effect on battery performance. Currently, the membranes used in aqueous flow battery technologies are very limited. In this feature article, we first cover the application of porous membranes in vanadium flow battery technology, and then the membranes in most recently reported aqueous flow battery systems. Meanwhile, we hope that this feature article will inspire more efforts to design and prepare membranes with outstanding performance and stability, and then accelerate the development of flow batteries for large scale energy storage applications. [ABSTRACT FROM AUTHOR]

The low specific capacity of graphite limits the further increase of the energy density of lithium-ion batteries and their widespread applications. Exploring new anode materials is the key issue. Herein, a new mullite-type compound Bi2Mn4O10 is designed and synthesized. The Bi2Mn4O10/C composite delivers a high reversible specific capacity of 846 mA h g−1 (more than twice that of graphite), and exhibits a high capacity retention of 100% after 300 cycles at 600 mA g−1, which is reported for the first time. The high specific capacity originates from the combination of the conversion reaction and alloying–dealloying reaction, which has been confirmed by the ex situ XRD, IR, SEM and TEM studies. In addition, the unique nanocomposite generated during the charge–discharge process provides excellent cycling stability. This work proves that Bi2Mn4O10/C is a potential anode material for advanced lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Lithium–sulfur batteries are promising for next-generation energy storage devices due to the high energy density and low material cost. However, their development is hampered by the short cycling life and severe polarization induced by shuttle effect of polysulfides and sluggish kinetics of Li2S. Herein, for the first time, LiTi2(PO4)2.88F0.12 (LTP-F0.12) is proposed to anchor and activate sulfide based on its strong interaction with lithium polysulfide and rapid charge transfer behavior. By adding 10 wt% LTP-F0.12 to the cathode, the discharge capacity and discharge rate performance were apparently improved, while the capacity retention of about 70% at 0.1C after 200 cycles was realized, which was much higher than that of pure SP–S cathode (lower than 50%). The activation energy (voltage polarization) was decreased by almost 40%. Additional capacity of 132 mA h g−1 was also provided by the LTP-F0.12 from 3.0 to 1.85 V. This study presents a new insight in promoting the polysulfide conversion kinetics in the sulfur cathode. [ABSTRACT FROM AUTHOR]