Zn Anode Surviving Extremely Corrosive Polybromide Environment with Alginate-Graphene Oxide Hydrogel Coating.

Zinc-bromine (Zn-Br) redox provides a high energy density and low-cost option for next-generation energy storage systems, and polybromide diffusion remains a major issue leading to Zn anode corrosion, dendrite growth, battery self-discharge and limited electrochemical performance. A dual-functional Alginate-Graphene Oxide (AGO) hydrogel coating is proposed to prevent polybromide corrosion and suppress dendrite growth in Zn-Br batteries through negatively charged carboxyl groups and enhanced mechanical properties. The battery with anode of plain zinc coated with AGO (Zn]AGO) survives a severely corrosive environment with higher polybromide concentration than usual without a membrane, and achieves 80 cycles with 100% Coulombic and 80.65% energy efficiencies, four times compared to plain Zn anode. The promising performance is comparable to typical Zn-Br batteries using physical membranes, and the AGO coating concept can be well adapted to various Zn-Br systems to promote their applications.

An Ultra-Low Self-Discharge Aqueous|Organic Membraneless Battery with Minimized Br2 Cross-Over.

Batteries dissolving active materials in liquids possess safety and size advantages compared to solid-based batteries, yet the intrinsic liquid properties lead to material cross-over induced self-discharge both during cycling and idle when the electrolytes are in contact, thus highly efficient and cost-effective solutions to minimize cross-over are in high demand. An ultra-low self-discharge aqueous|organic membraneless battery using dichloromethane (CH2 Cl2 ) and tetrabutylammonium bromide (TBABr) added to a zinc bromide (ZnBr2 ) solution as the electrolyte is demonstrated. The polybromide is confined in the organic phase, and bromine (Br2 ) diffusion-induced self-discharge is minimized. At 90% state of charge (SOC), the membraneless ZnBr2 |TBABr (Z|T) battery shows an open circuit voltage (OCV) drop of only 42 mV after 120 days, 152 times longer than the ZnBr2  battery, and superior to 102 previous reports from all types of liquid active material batteries. The 120-day capacity retention of 95.5% is higher than commercial zinc-nickel (Zn-Ni) batteries and vanadium redox flow batteries (VRFB, electrolytes stored separately) and close to lithium-ion (Li-ion) batteries. Z|T achieves >500 cycles (2670 h, 0.5 m electrolyte, 250 folds of membraneless ZnBr2  battery) with ≈100% Coulombic efficiency (CE). The simple and cost-effective design of Z|T provides a conceptual inspiration to regulate material cross-over in liquid-based batteries to realize extended operation.

Halogenated Functional Electrolyte Additive for Li-CO2 Batteries.

In recent years, functional electrolyte additives have been widely studied during the CO2 evolution reaction (CO2ER) and CO2 reduction reaction (CO2RR) processes for Li-CO2 batteries. Owing to different concerns, functions of these additives are also multiple and limited. In this work, the multiple impacts of functional electrolyte additives for Li-CO2 batteries are discussed. N-phenylpyrrolidine (PPD) and 1-(3-bromophenyl) pyrrole (Br-PPD) are investigated as additives successively. First, the corresponding charging potential during the CO2ER process can be reduced to 3.65 V with PPD; then the Li||Li symmetric cells with Br-PPD possess a superior long-term cycling of 800 h benefited from a stable solid electrolyte interphase (SEI) on the surface of a Li metal by using a Li anode protected with bromine functional groups. In Br-PPD-based Li-CO2 cells, the charging potential can be maintained at 3.70 V for 120 cycles even with a Super P cathode. In this work, the relationship between the structural properties of organic molecules and their electrochemical applications is discussed and investigated. This is essential for the targeted design and preparation of additives in rechargeable batteries.

Recent Advances in Porous Carbon Materials as Electrodes for Supercapacitors.

Porous carbon materials have demonstrated exceptional performance in various energy and environment-related applications. Recently, research on supercapacitors has been steadily increasing, and porous carbon materials have emerged as the most significant electrode material for supercapacitors. Nonetheless, the high cost and potential for environmental pollution associated with the preparation process of porous carbon materials remain significant issues. This paper presents an overview of common methods for preparing porous carbon materials, including the carbon-activation method, hard-templating method, soft-templating method, sacrificial-templating method, and self-templating method. Additionally, we also review several emerging methods for the preparation of porous carbon materials, such as copolymer pyrolysis, carbohydrate self-activation, and laser scribing. We then categorise porous carbons based on their pore sizes and the presence or absence of heteroatom doping. Finally, we provide an overview of recent applications of porous carbon materials as electrodes for supercapacitors.

The Progress of Hard Carbon as an Anode Material in Sodium-Ion Batteries.

When compared to expensive lithium metal, the metal sodium resources on Earth are abundant and evenly distributed. Therefore, low-cost sodium-ion batteries are expected to replace lithium-ion batteries and become the most likely energy storage system for large-scale applications. Among the many anode materials for sodium-ion batteries, hard carbon has obvious advantages and great commercial potential. In this review, the adsorption behavior of sodium ions at the active sites on the surface of hard carbon, the process of entering the graphite lamellar, and their sequence in the discharge process are analyzed. The controversial storage mechanism of sodium ions is discussed, and four storage mechanisms for sodium ions are summarized. Not only is the storage mechanism of sodium ions (in hard carbon) analyzed in depth, but also the relationships between their morphology and structure regulation and between heteroatom doping and electrolyte optimization are further discussed, as well as the electrochemical performance of hard carbon anodes in sodium-ion batteries. It is expected that the sodium-ion batteries with hard carbon anodes will have excellent electrochemical performance, and lower costs will be required for large-scale energy storage systems.

Three-Dimensional Honeycomb-Like Carbon as Sulfur Host for Sodium-Sulfur Batteries without the Shuttle Effect.

Sodium-sulfur batteries operating at ambient temperature are being extensively studied because of the high theoretical capacity and abundant resources, yet the long-chain polysulfides' shuttle effect causes poor cycling performance of Na-S batteries. We report an annealing/etching method to converse low-cost wheat bran to a 3D honeycomb-like carbon with abundant micropores (WBMC), which is smaller than S8 molecular size (∼0.7 nm). Thus, the microporous structure could only fill small molecular sulfur (S2-4). The micropores made sulfur a one-step reaction without the shuttle effect due to the formed short-chain polysulfides being insoluble. The WBMC@S exhibits an excellent initial capacity (1413 mAh g-1) at 0.2 C, outstanding cycling performance (822 mAh g-1 after 100 cycles at 0.2 C), and high rate performance (483 mAh g-1 at 3.0 C). The electrochemical performance proves that the steric confinement of micropores effectively terminates the shuttle effect.

A Review on Electrode Materials of Fast-Charging Lithium-Ion Batteries.

In recent years, the driving range of electric vehicles (EVs) has been dramatically improved. But the large-scale adoption of EVs still is hindered by long charging time. The high-energy LIBs are unable to be safely fast-charged due to their electrode materials with unsatisfactory rate performance. Thus it is necessary to summarize the properties of cathode and anode materials of fast-charging LIBs. In this review, we summarize the background, the fundamentals, electrode materials and future development of fast-charging LIBs. First, we introduce the research background and the physicochemical basics for fast-charging LIBs. Second, typical cathode materials of LIBs and the method to enhancing their fast-charging properties are discussed. Third, the anode materials of LIBs and the strategies for improving their fast-charging performance are analyzed. Finally, the future development of the cathode materials in fast-charging LIBs is prospected.

NASICON type KTi2(PO4)3 decorated by NTCDA-derived carbon layer for enhanced lithium/sodium storage.

NASICON type KTi2(PO4)3 decorated by NTCDA-derived carbon layer (KTP/NC) was prepared as anode material to obtain sustainable lithium/sodium ion storage (LIBs/SIBs). Due to its prominent capacitance, good electronic conductivity and ability to constrain volume, the KTP/NC composite realizes highly electrochemical kinetics both in LIBs and SIBs. For LIBs, the KTP/NC composite delivers a superior reversible capacity of 598.1 mAh g-1 after 200 cycles at 0.5C, impressive cyclability with 225.5 mAh g-1 after 3000 cycles at an ultrahigh current density of 26.1 C and conspicuous rate performance of 160.6 mAh g-1 even at 52.2 C. In addition, the composite has a wide operation-temperature window with favorable capacities of 147.1-372.9 mAh g-1 from -10 °C to 50 °C. As for SIBs, the KTP/NC composite maintains a stable discharge capacity of 112.5 mAh g-1 after 700 cycles at a current density of 2.6 C and conspicuous rate performance of 86.7 mAh g-1 at 5.2 C. The KTP/NC anode exhibits discharge capacities of 29.9-112.6 mAh g-1 from -10 °C to 40 °C. The results demonstrate that the KTP/NC composite would be a promising electrode material for LIBs and SIBs.

Vertical 2-dimensional heterostructure SnS-SnS2 with built-in electric field on rGO to accelerate charge transfer and improve the shuttle effect of polysulfides.

Traditional carbon materials as sulfur hosts of Li-sulfur(Li-S) cathodes have slightly physical constraint for polysulfides, due to their no-polar property. Therefore, it is necessary to further enhance the affinity between sulfur hosts and polysulfides, and relieve the shuttle effects in the Li- S batteries. Herein, we report a novel vertical 2-dimensional (2D) p-SnS/n-SnS2 heterostructure sheets which grown on the surface of rGO. The excellent electrochemical properties of SnS-SnS2@rGO as Li-S cathode are ascribed to the stronger absorption effect of metal sulphides for polysulfides and the smooth trapping-diffusion-conversion effect of p-SnS/n-SnS2 heterostructure for polysulfides. As a conductive carrier for the growth of vertical 2D p-SnS/n-SnS2 heterostructure nanosheets, rGO can protect the steadiness and enhance the cycle stability of electrode, compared with heterostructure without rGO. In addition, the built-in electric field in the 2D p-SnS/n-SnS2 heterostructure during the discharge/charge processes can effectively accelerate charge transfer, and the charge transfer mechanism in SnS-SnS2 heterostructure during cycling has been investigated. At a rate capability of 2C, the designed SnS-SnS2@rGO as Li-S cathode delivers high specific capacities of 907 mAh g-1 and 571 mAh g-1 after the first cycle and 500 cycles, respectively, which shown excellent cycling ability.

Porous Co2VO4 Nanodisk as a High-Energy and Fast-Charging Anode for Lithium-Ion Batteries.

High-energy-density lithium-ion batteries (LIBs) that can be safely fast-charged are desirable for electric vehicles. However, sub-optimal lithiation potential and low capacity of commonly used LIBs anode cause safety issues and low energy density. Here we hypothesize that a cobalt vanadate oxide, Co2VO4, can be attractive anode material for fast-charging LIBs due to its high capacity (~ 1000 mAh g-1) and safe lithiation potential (~ 0.65 V vs. Li+/Li). The Li+ diffusion coefficient of Co2VO4 is evaluated by theoretical calculation to be as high as 3.15 × 10-10 cm2 s-1, proving Co2VO4 a promising anode in fast-charging LIBs. A hexagonal porous Co2VO4 nanodisk (PCVO ND) structure is designed accordingly, featuring a high specific surface area of 74.57 m2 g-1 and numerous pores with a pore size of 14 nm. This unique structure succeeds in enhancing Li+ and electron transfer, leading to superior fast-charging performance than current commercial anodes. As a result, the PCVO ND shows a high initial reversible capacity of 911.0 mAh g-1 at 0.4 C, excellent fast-charging capacity (344.3 mAh g-1 at 10 C for 1000 cycles), outstanding long-term cycling stability (only 0.024% capacity loss per cycle at 10 C for 1000 cycles), confirming the commercial feasibility of PCVO ND in fast-charging LIBs.

Core-Shell Co2VO4/Carbon Composite Anode for Highly Stable and Fast-Charging Sodium-Ion Batteries.

Sodium-ion batteries (SIBs) are promising candidates for large-scale energy storage systems due to the abundance and wide distribution of sodium resources. Various solutions have been successfully applied to revolve the large-ion-size-induced battery issues at the mid-to-low current density range. However, the fast-charging properties of SIBs are still in high demand to accommodate the increasing energy needs at large to grid scales. Herein, a core-shell Co2VO4/carbon composite anode is designed to tackle the fast-charging problem of SIBs. The synergetic effect from the stable spinel structure of Co2VO4, the size of the nanospheres, and the carbon shell provide enhanced Na+ ion diffusion and electron transfer rates and outstanding electrochemical performance. With an ultrahigh current density of 5 A g-1, the Co2VO4@C anode achieved a capacity of 135.1 mAh g-1 and a >98% capacity retention after 2000 cycles through a pseudocapacitive dominant process. This study provides insights for SIB fast-charging material design and other battery systems such as lithium-ion batteries.

Four Novel d10 Metal-Organic Frameworks Incorporating Amino-Functionalized Carboxylate Ligands: Synthesis, Structures, and Fluorescence Properties.

By employment of amino-functionalized dicarboxylate ligands to react with d10 metal ions, four novel metal-organic frameworks (MOFs) were obtained with the formula of {[Cd(BCPAB)(µ 2-H2O)]} n (1), {[Cd(BDAB)]∙2H2O∙DMF} n (2), {[Zn(BDAB)(BPD)0.5(H2O)]∙2H2O} n (3) and {[Zn(BDAB)(DBPB)0.5(H2O)]∙2H2O} n (4) (H2BCPAB = 2,5-bis(p-carbonylphenyl)-1-aminobenzene; H2BDAB = 1,2-diamino-3,6-bis(4-carboxyphenyl)benzene); BPD = (4,4'-bipyridine); DBPB = (E,E-2,5-dimethoxy-1,4-bis-[2-pyridin-vinyl]-benzene; DMF = N,N-dimethylformamide). Complex 1 is a three-dimensional (3D) framework bearing seh-3,5-Pbca nets with point symbol of {4.62}{4.67.82}. Complex 2 exhibits a 4,4-connected new topology that has never been reported before with point symbol of {42.84}. Complex 3 and 4 are quite similar in structure and both have 3D supramolecular frameworks formed by 6-fold and 8-fold interpenetrated 2D coordination layers. The structures of these complexes were characterized by single crystal X-ray diffraction (SC-XRD), thermal gravimetric analysis (TGA) and powder X-ray diffraction (PXRD) measurements. In addition, the fluorescence properties and the sensing capability of 2-4 were investigated as well and the results indicated that complex 2 could function as sensor for Cu2+ and complex 3 could detect Cu2+ and Ag+ via quenching effect.

Sulfur nanoparticles/Ti3C2Tx MXene with an optimum sulfur content as a cathode for highly stable lithium-sulfur batteries.

Lithium-sulfur batteries have a high theoretical energy density but they need better sulfur host materials to retain the lithium polysulfide shuttle effect, which results in the batteries' capacity fading. Titanium carbide MXene (Ti3C2Tx MXene) is an excellent host for the sulfur cathode because of its layered-stacked structure and many surface termination groups. The sulfur content in S/Ti3C2Tx MXene composites is an important factor affecting the cathodes' electrochemical performance. In this work, S/Ti3C2Tx MXene composites with different sulfur contents are prepared by a one-step hydrothermal process, and the influence of the sulfur content in the S/Ti3C2Tx MXene composite on the S/Ti3C2Tx MXene cathode's electrochemical performance is studied. When the mass ratio of sulfur to MXene in the reactant is 4 : 1, the sulfur nanoparticles are uniformly filled in the layered-stacked structure. The layered-stacked structure can buffer the volume expansion of sulfur during cycling and the surface termination groups exhibit strong adsorption of LiPSn. Thus, the S/MXene composite with an optimum sulfur content (67.0 wt%) demonstrates an excellent electrochemical performance, including a high initial reversible capacity (1277 mA h g-1 at 0.5 C) and the best cycling performance (1059 mA h g-1 at 0.5 C after 100 cycles). This work offers a guide to developing advanced S-based cathode materials with an appropriate S content for lithium sulfur batteries.

Smooth Muscle Cell Responses to Poly(ε-Caprolactone) Triacrylate Networks with Different Crosslinking Time.

Poly(ε-caprolactone) triacrylate (PCLTA) is attractive in tissue engineering because of its good biocompatibility and processability. The crosslinking time strongly influences PCLTAs cellular behaviors. To investigate these influences, PCLTAs with different molecular weights were crosslinked under UV light for times ranging from 1 to 20 min. The crosslinking efficiency of PCLTA increased with decreasing the molecular weight and increasing crosslinking time which could increase the gel fraction and network stiffness and decrease the swelling ratio. Then, the PCLTA networks crosslinked for different time were used as substrates for culturing rat aortic smooth muscle cells (SMCs). SMC attachment and proliferation all increased when the PCLTA molecular weight increased from 8k to 10k and then to 20k at the same crosslinking time. For the same PCLTA, SMC attachment, proliferation, and focal adhesions increased with increasing the crosslinking time, in particular, between the substrates crosslinked for less than 3 min and longer than 5 min. This work will provide a good experimental basis for the application of PCLTA.