Design,preparation,application of advanced array structured materials and their action mechanism analyses for high performance lithium-sulfur batteries

Lithium-sulfur battery(LSB)has brought much attention and concern because of high theoretical specific capacity and energy density as one of main competitors for next-generation energy storage systems.The widely commercial application and development of LSB is mainly hindered by serious“shuttle effect”of lithium polysulfides(Li PSs),slow reaction kinetics,notorious lithium dendrites,etc.In various structures of LSB materials,array structured materials,possessing the composition of ordered micro units with the same or similar characteristics of each unit,present excellent application potential for various secondary cells due to some merits such as immobilization of active substances,high specific surface area,appropriate pore sizes,easy modification of functional material surface,accommodated huge volume change,enough facilitated transportation for electrons/lithium ions,and special functional groups strongly adsorbing Li PSs.Thus many novel array structured materials are applied to battery for tackling thorny problems mentioned above.In this review,recent progresses and developments on array structured materials applied in LSBs including preparation ways,collaborative structural designs based on array structures,and action mechanism analyses in improving electrochemical performance and safety are summarized.Meanwhile,we also have detailed discussion for array structured materials in LSBs and constructed the structure-function relationships between array structured materials and battery performances.Lastly,some directions and prospects about preparation ways,functional modifications,and practical applications of array structured materials in LSBs are generalized.We hope the review can attract more researchers'attention and bring more studying on array structured materials for other secondary batteries including LSB.

Intercalation engineering of layered vanadyl phosphates for high performance zinc-ion batteries

Aqueous zinc-ion batteries(ZIBs) have attracted great attention as the candidates for large-scale energy storage system,recently,because of their low cost,environment-friendly,high safety,and high theoretical energy densities.Among the numerous cathode materials,layered structure vanadium based polyanionic compounds,such as VOPO_(4),exhibit high specific capacity for Zn ion storage.However,the low Zn ion diffusion coefficient and limited interlayer spacing make the cathodes low reversible capacity and inferior cycling stability.Herein,K ions were pre-intercalated into the VOPO_(4) layers via ions exchange adopting VOPO_(4)·2 H_(2) O as the precursor.When evaluated as the cathode for ZIBs,an excellent cycle stability of 400 cycles under a current density of 500 mA g^(-1) was achieved by the obtained KVOPO_(4) electrode,verifying the positive effect of intercalation engineering.Furtherly,a solid-solution reaction Zn ion storage mechanism was confirmed.This study provides a new insight to explore high performance cathode materials for ZIBs.

Unscramble to the national standard of quality management in China

This paper introduces the main content of the national standard of quality management in China---the GB/T 19580 Criteria for Performance excellence.The scope,purpose,the difference from ISO 9001 and evaluation requirements are described.

Hydrogen Bond-Assisted Ultra-Stable and Fast Aqueous NH_(4)^(+)Storage

Aqueous ammonium ion batteries are regarded as eco-friendly and sustainable energy storage systems.And applicable host for NH_(4)^(+)in aqueous solution is always in the process of development.On the basis of density functional theory calcula-tions,the excellent performance of NH_(4)^(+)insertion in Prussian blue analogues(PBAs)is proposed,especially for copper hexacyanoferrate(CuHCF).In this work,we prove the outstanding cycling and rate performance of CuHCF via electrochemical analyses,delivering no capacity fading during ultra-long cycles of 3000 times and high capacity retention of 93.6%at 50 C.One of main contributions to superior performance from highly reversible redox reaction and structural change is verified during the ammoniation/de-ammoniation progresses.More importantly,we propose the NH_(4)^(+)diffusion mechanism in CuHCF based on con-tinuous formation and fracture of hydrogen bonds from a joint theoretical and experimental study,which is another essential reason for rapid charge transfer and superior NH_(4)^(+)storage.Lastly,a full cell by coupling CuHCF cathode and polyaniline anode is constructed to explore the practical application of CuHCF.In brief,the outstanding aqueous NH_(4)^(+)storage in cubic PBAs creates a blueprint for fast and sustainable energy storage.

Recent advances of high-entropy electrocatalysts for water electrolysis by electrodeposition technology:a short review

Hydrogen is considered as the promising energy carrier to substitute traditional fossil fuel,due to its cleanliness,renewability and high energy density.Water electrolysis is a simple and eonvenient technology for hydrogen production.The efficiency of water electrolysis for hydrogen production is limited by the electrocatalytic performances on hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).The exorbitant Pt-and Ir-/Ru-based electrocatalysts as optimal HER and OER electrocatalysts,respectively,restrict water electrolysis development.Recently,non-precious metal-based high-entropy electrocatalysts have exhibited excellent electrocatalytic activities and long-term stabilities for water electrolysis,as promising precious cataly st candidates.Therefore,the construction of the high-entropy electroc atalysts is vital to water electrolysis industry.Electrodeposition technology is an efficient method for the preparation of high-entropy electrocatalysts due to its simple,fast,energy-saving and environmental-friendly advantages.Multi-component co-precipitation facilely occurs during the electroredox in electrodeposition processes.High-entropy alloys,oxides,(oxy)hydroxides,phosphides and phosphorus sulfide oxides have been successfully prepared by galvanostatic,potentiostatic electrodeposition,cyclic voltammetry,pulse,nanodroplet-mediated and cathodic plasma electrodeposition techniques.Hence,introduction of the development of high-entropy electrocatalysts synthesized by electrodeposition technology is significant to researchers and industries.Challenges and outlooks are also concluded to boost the industrial application of electrodeposition in water electrolysis and other energy conversion areas.

Calcium-organic frameworks cathode for high-stable aqueous Zn/organic batteries

Rechargeable aqueous zinc-ion batteries(AZIBs) are attracting tremendous attention because of their intrinsic merits such as high safety and low cost. Cathode plays a critical role in enhancing the electrochemical performance of AZIBs. However, it is difficult to design a robust and high-efficiency cathode material and further implement the commercialization of AZIBs. Metal-organic frameworks(MOFs) electroactive compounds are attractive to serve as the cathode of AZIBs due to their unique porosity and crystal structures, resource renewability and structural diversity. In this work, a calcium-pure terephthalates acid framework(Ca-PTA·3H_(2)O) was synthesized by facile hydrolysis and cationic exchange method,then explored as a novel cathode for AZIBs. The results highlight a high specific capacity of 431 mAh/g(0.51 mAh/cm^(2)) at a current density of 50 mA/g, and excellent cycle performance with capacity retention of ~90% after 2700 cycles at 500 m A/g. The following up characterizations investigate the reversible zinc storage mechanism in detail. This experiment made a specific contribution to the exploration of the new MOF as a competitive cathode for AZIBs.

Mace-like TTF-TCNQ/HKUST-1 composite structures for rapid NO_(2) detection: Synergistically induced ultrahigh sensitivity and outstanding selectivity

Integration and synergy of the unique functions of different components have been developed into one of the most convenient and effective ways to construct the composite advanced materials with collective properties and improved performances.In this work,the mace-like tetrathiafulvalene-tetracyanoquinodimethane(TTF-TCNQ)/HKUST-1 composite structures with single single-crystalline TTF-TCNQ submicrorods covered by ordered HKUST-1 nanosheet arrays were successfully constructed by an efficient TTF-TCNQ seed-mediated growth approach.Impressively,thanks to the synergetic and complementary effects between TTF-TCNQ and HKUST-1,the sensors based on such mace-like TTF-TCNQ/HKUST-1 composite structures not only displayed an experimental detection limit of 10 part per billion(ppb)for NO_(2) detection,but also exhibited outstanding selectivity even if the concentration of the interfering gases was 10 times that of NO_(2).Meanwhile,good reproducibility and rapid response were also achieved.This work opens the avenue for creation of novel high-performance sensing materials for application in gas sensing.

Rational design of nitrogen doped hierarchical porous carbon for optimized zinc-ion hybrid supercapacitors

Aqueous rechargeable zinc-ion hybrid supercapacitors are considered to be a promising candidate for large-scale energy storage devices owing to their high safety,long life,and low price.In this paper,a nitrogen doped hierarchical porous carbon is evaluated as the cathode for aqueous rechargeable zinc-ion hybrid supercapacitors.Benefiting from the synergistic merits of excellent structural features of N-HPC and tiny zinc dendrite of Zn anode in ZnSO4 electrolyte,the zinc-ion hybrid supercapacitor exhibits excellent energy storage performance including high capacity of 136.8 mAh·g^−1 at 0.1·Ag^−1,high energy density of 191 Wh·kg^−1,large power density of 3,633.4 W·kg^−1,and satisfactory cycling stability of up to 5,000 cycles with a capacity retention of 90.9%.This work presents a new prospect of developing high-performance aqueous rechargeable zinc ion energy storage devices.

High power and stable P-doped yolk-shell structured Si@C anode simultaneously enhancing conductivity and Li^(+)diffusion kinetics

Silicon is a low price and high capacity ancxje material for lithium-ion batteries.The yolk-shell structure can effectively accommodate Si expansion to improve stability.However,the limited rate performance of Si anodes can't meet people's growing demand for high power density.Herein,the phosphorus-doped yolk-shell Si@C materials(P-doped Si@C)were prepared through carbon coating on P-doped Si/SiO_(x)matrix to obtain high power and stable devices.Therefore,the as-prepared P-doped Si@C electrodes delivered a rapid increase in Coulombic efficiency from 74.4%to 99.6%after only 6 cycles,high capacity retention of-95%over 800 cycles at 4 A·g^(-1),and great rate capability(510 mAh·g^(-1)at 35 A·g^(-1)).As a result,P-doped Si@C anodes paired with commercial activated carbon and LiFePO_(4)cathode to assemble lithium-ion capacitor(high power density of〜61,080 W·kg^(-1)at 20 A·g^(-1))and lithium-ion full cell(good rate performance with 68.3 mAh·g^(-1)at 5 C),respectively.This work can provide an effective way tofurther improve power density and stability for energy storage devices.

Fe_(0.8)CoSe_(2) nanosphere coated by N-doped carbon for ultra- high rate potassium selenium battery

Potassium-selenium(K-Se) batteries are a promising electrical energy storage candidate because of the cost-effectiveness and material sustainability, yet they suffer from shuttle effect, volume expansion and low powder density. The development of Se-based cathode is an effective way to overcome the above issues. Here we designed a hollow nano-spherical Co-Fe bi-metallic selenide coated with N-doped carbon(denoted as CFS@N-C)as cathode for K-Se batteries. Bimetallic selenide is benefit to improve the conductivity of composite materials;N-doped carbon layer encapsulation effectively inhibits the dissolution of poly-selenides and relieves the volume expansion. The as-prepared K-Se battery exhibits excellent rate performance(300 mAh·g^(-1) at 1000 mA·g^(-1)) and slowcharge/ultrafast-dischargecapability(dischargeat5000 mA·g^(-1) and charge at 100 mA·g^(-1) with ultrahigh capacity of 227 mAh·g^(-1)) with Coulombic efficiency nearly 100%. In addition, the ex-situ high-resolution transmission electron microscopy(HRTEM) images reveal that the charge–discharge mechanism of CFS@N-C is K^(+) replaces the bimetal and forms K_(2)Se. The unique design in this work may provide certain directions on researching for high power density K-storage materials.