Spray pyrolysis feasibility of tungsten substitution for cobalt in nickel-rich cathode materials

Cobalt(Co)serves as a stabilizer in the lattice structure of high-capacity nickel(Ni)-rich cathode materials.However,its high cost and toxicity still limit its development.In general,it is possible to perform transition metal substitution to reduce the Co content.However,the traditional coprecipitation method cannot satisfy the requirements of multielement coprecipitation and uniform distribution of elements due to the differences between element concentration and deposition rate.In this work,spray pyrolysis was used to prepare LiNi_(0.9)Co_(0.1-x)W_(x)O_(2)(LNCW).In this regard,the pyrolysis behavior of ammonium metatungstate was analyzed,together with the substitu-tion of W for Co.With the possibility of spray pyrolysis,the Ni-Co-W-containing oxide precursor presents a homogeneous distribution of metal elements,which is beneficial for the uniform substitution of W in the final materials.It was observed that with W substitution,the size of primary particles decreased from 338.06 to 71.76 nm,and cation disordering was as low as 3.34%.As a consequence,the pre-pared LNCW exhibited significantly improved electrochemical performance.Under optimal conditions,the lithium-ion battery assembled with LiNi_(0.9)Co_(0.0925)W_(0.0075)O_(2)(LNCW-0.75mol%)had an improved capacity retention of 82.7%after 200 cycles,which provides insight in-to the development of Ni-rich low-Co materials.This work presents that W can compensate for the loss caused by Co deficiency to a cer-tain extent.

High-Performance Quasi-Solid-State Pouch Cells Enabled by in situ Solidification of a Novel Polymer Electrolyte

Conventional lithium-ion batteries(LIBs)with liquid electrolytes are challenged by their big safety concerns,particularly used in electric vehicles.All-solid-state batteries using solid-state electrolytes have been proposed to significantly improve safety yet are impeded by poor interfacial solid–solid contact and fast interface degradation.As a compromising strategy,in situ solidification has been proposed in recent years to fabricate quasi-solid-state batteries,which have great advantages in constructing intimate interfaces and cost-effective mass manufacturing.In this work,quasi-solid-state pouch cells with high loading electrodes(≥3 m Ah cm^(-2))were fabricated via in situ solidification of poly(ethylene glycol)diacrylate-based polymer electrolytes(PEGDA-PEs).Both single-layer and multilayer quasi-solid-state pouch cells(2.0 Ah)have demonstrated stable electrochemical performance over500 cycles.The superb electrochemical stability is closely related to the formation of robust and compatible interphase,which successfully inhibits interfacial side reactions and prevents interfacial structural degradation.This work demonstrates that in situ solidification is a facile and cost-effective approach to fabricate quasi-solid-state pouch cells with both excellent electrochemical performance and safety.

Engineered Cleistogamy in Camelina sativa for bioconfinement

Camelina sativa is a self-pollinating and facultative outcrossing oilseed crop.Genetic engineering has been used to improve camelina yield potential for altered fatty acid composition,modified protein profiles,improved seed and oil yield,and enhanced drought resistance.The deployment of transgenic camelina in the field posits high risks related to the introgression of transgenes into nontransgenic camelina and wild relatives.Thus,effective bioconfinement strategies need to be developed to prevent pollen-mediated gene f low(PMGF)from transgenic camelina.In the present study,we overexpressed the cleistogamy(i.e.f loral petal non-openness)-inducing PpJAZ1 gene from peach in transgenic camelina.Transgenic camelina overexpressing PpJAZ1 showed three levels of cleistogamy,affected pollen germination rates after anthesis but not during anthesis,and caused a minor silicle abortion only on the main branches.We also conducted field trials to examine the effects of the overexpressed PpJAZ1 on PMGF in the field,and found that the overexpressed PpJAZ1 dramatically inhibited PMGF from transgenic camelina to non-transgenic camelina under the field conditions.Thus,the engineered cleistogamy using the overexpressed PpJAZ1 is a highly effective bioconfinement strategy to limit PMGF from transgenic camelina,and could be used for bioconfinement in other dicot species.

＂外源基因清除＂技术(Gene-Deletor)原理、特点及其潜在应用前景

"外源基因清除"技术(Gene-Deletor)是美国康涅狄格大学华裔教授李义领导的研究小组发展起来的,有望成为解决转基因植物环境安全性和食品安全性问题的有力工具。象计算机"卸载"应用软件一样,"外源基因清除"技术利用器官特异或诱导型启动子、重组酶及融合识别位点构建基因表达元件,能将转基因植物中的全部外源基因在完成其功能作用后自动地从花粉、种子和果实中彻底清除。最近,美国著名"社会技术"公司公布了未来20年对社会最具影响力、最有前景的技术创新领域一系列12个简报,其中第10个专题推介了"外源基因清除"技术。本文综述了"外源基因清除"技术的原理和技术优点,介绍并讨论了李义对该技术在作物有性繁殖中的应用以及在解决食品安全性问题上的应用方略。

Recent progress on confinement of polysulfides through physical andchemical methods

With high theoretical energy density and the natural abundance of S, lithium-sulfur （Li-S） batteries areconsidered to be the promising next generation high-energy rechargeable energy storage devices. How-ever, issues including electronical insulation of S, the lithium polysulfides （LiPSs） dissolution and the shortcycle lifespan have prevented Li-S batteries from being practical applied. Feasible settlements of confiningLiPSs to reduce the loss of active substances and improve the cycle stability include wrapping sulfur withcompact layers, designing matrix with porous or hollow structures, adding adsorbents owning stronginteraction with sulfur and inserting polysulfide barriers between cathodes and separators. This reviewcategorizes them into physical and chemical confinements according to the influencing mechanism. Withfurther discussion of their merits and flaws, synergy of the physical and chemical confinement is believedto be the feasible avenue that can guide Li-S batteries to the practical application.

New opportunities for using WUS/BBM and GRF-GIF genes to enhance genetic transformation of ornamental plants

Broad application of plant transformation remains challenging because the efficiency of plant regeneration and regeneration-based transformation in many plant species is extremely low.Many species and genotypes are not responsive to traditional hormone-based regeneration systems.This regeneration recalcitrance hampers the application of many technologies such as micropropagation,transgenic breeding,and gene editing in various plant species,including ornamental flowers,shrubs,and trees.Various developmental genes have long been studied for their ability to improve plant meristematic induction and regeneration.Lately,it was demonstrated that the combined and refined expression of morphogenic regulator genes WUSCHEL and BABY BOOM could alleviate their pleiotropic effects and permit transformation in recalcitrant monocots.Moreover,ectopic expression of plant growth-regulating factors(GRFs)alone or in combination with GRF-interacting factors(GIFs)improved the regeneration and transformation of dicot and monocot species.Fine-tuning the expression of these genes provides new opportunities to improve transformation efficiencies and facilitate the application of new breeding technologies in ornamental plants.

Bilateral posterior scleritis presenting as acute primary angle closure:A case report

BACKGROUND Scleritis is a rare disease and the incidence of bilateral posterior scleritis is even rarer.Unfortunately,misdiagnosis of the latter is common due to its insidious onset,atypical symptoms,and varied manifestations.We report here a case of bilateral posterior scleritis that presented with acute eye pain and intraocular hypertension,and was initially misdiagnosed as acute primary angle closure.Expanding the literature on such cases will not only increase physicians’awareness but also help to improve accurate diagnosis.CASE SUMMARY A 53-year-old man was referred to our hospital to address a 4-d history of bilateral acute eye pain,headache,and loss of vision,after initial presentation to a local hospital 3 d prior.Our initial examination revealed bilateral cornea edema accompanied by a shallow anterior chamber and visual acuity reduction,with left-eye amblyopia(>30 years).There was bilateral hypertension(by intraocular pressure:28 mmHg in right,34 mmHg in left)and normal fundi.Accordingly,acute primary angle closure was diagnosed.Miotics and ocular hypotensive drugs were prescribed,but the symptoms continued to worsen over the 3-d treatment course.Further imaging examinations(i.e.,anterior segment photography and ultrasonography)indicated a diagnosis of bilateral posterior scleritis.Methylprednisolone,topical atropine,and steroid eye drops were prescribed along with intraocular pressure-lowering agents.Subsequent optical coherence tomography(OCT)showed gradual improvements in subretinal fluid under the sensory retina,thickened sclera,and ciliary body detachment.CONCLUSION Bilateral posterior scleritis can lead to secondary acute angle closure.Diagnosis requires ophthalmic accessory examinations(i.e.,ultrasound biomicroscopy,Bscan,and OCT).

Trapping precursor-level functionalities in hierarchically porous carbons prepared by a pre-stabilization route for superior supercapacitors

Versatile module design of precursor networks enables flexible functionalization of nano-carbon electrode materials to meet the adaptable energy-storage demand. Functionalized heterogeneous networks are more likely to decompose by swift temperature programming together with predesign module removal, so high functionality/network transfer from precursor to carbon is still a work in progress. A pre-stabilization route is proposed here to enhance the network strength at early pyrolysis and pin up precursor-level functionalities on the final carbon. Such strategy successfully fixes more electroactive N(4.28-8.86 wt%) into the resultant carbon microspheres compared with non-pretreated carbon(2.89wt%), as well as achieves broad ion-accessible platforms of 1575-2269 m^(2)/g with preset structural superiorities. As a result, a typical acidic device reveals an outstanding specific capacitance of 383 F/g at 10 mV/s. Taking advantage of a novel LiNO_(3)-PAM polymer electrolyte, the upgraded symmetric device displays the maximum specific capacitance of 229 F/g, along with a boosted energy density of 41.1 Wh/kg at 643.4 W/kg. This work opens up a feasible insight into realizing highly efficient precursor/electrode design toward superior system with outstanding energy/power feature and temperature applicability.

Self-supported hard carbon anode from fungus-treated basswood towards sodium-ion batteries

Hard carbon derived from biomass is regarded as a promising anode material for sodium-ion batteries(SIBs)because of its low operating potential,high capacity,resource availability,and low cost.However,scientific and technological challenges still exist to prepare hard carbon with a high initial Coulombic efficiency(ICE),an excellent rate capability,and good cycling stability.In this work,we report a self-supported hard carbon electrode from fungus-pretreated basswood with an improved graphitization degree and a low tortuosity.Compared with the hard carbon derived from basswood,the hard carbon electrode from fungus-pretreated basswood has an improved rate capability of 242.3 mAh·g^(−1)at 200 mA·g^(−1)and cycling stability with 93.9%of its capacity retention after 200 cycles at 40 mA·g^(−1),as well as the increased ICE from 84.3%to 88.2%.Additionally,ex-situ X-ray diffraction indicates that Na+adsorption caused the sloping capacity,whereas Na+intercalation between interlayer spacing corresponded to the low potential plateau capacity.This work provides a new perspective for the preparation of high-performance hard carbon and gains the in-depth understanding of Na storage mechanism.

Designing solid-state interfaces on lithium-metal anodes: a review

Li-metal anodes are one of the most promising energy storage systems that can considerably exceed the current technology to meet the ever-increasing demand of power applications. The apparent cycling performances and dendrite challenges of Li-metal anodes are highly influenced by the interface layer on the Li-metal anode because the intrinsic high reactivity of metallic Li results in an inevitable solid-state interface layer between the Li-metal and electrolytes. In this review, we summarize the recent progress on the interfacial chemistry regarding the interactions between electrolytes and ion migration through dynamic interfaces. The critical factors that affect the interface formation for constructing a stable interface with a low resistance are reviewed. Moreover, we review emerging strategies for rationally designing multiple-structured solid-state electrolytes and their interfaces, including the interfacial properties within hybrid electrolytes and the solid electrolyte/electrode interface. Finally, we present scientific issues and perspectives associated with Li-metal anode interfaces toward a practical Li-metal battery.

Moisture-preventing MAPbI_(3) solar cells with high photovoltaic performance via multiple ligand engineering

Perovskite solar cells present one of the most prominent photovoltaic technologies,yet their stability,and engineering at the molecular level remain challenging.We have demonstrated multifunctional molecules to improve the operating stability of perovskite solar cells while depicting a high-power conversion efficiency.The multifunctional molecule 4-[(trifluoromethyl)sulphanyl]-aniline(4TA)with trifluoromethyl(-CF_(3))and aniline(-NH_(2))moieties is meticulously designed to modulate the perovskite.The-CF_(3) and-NH_(2) functional groups have strong interaction with perovskite to suppress surface defects to improve device stability,as well as obtain large crystal grains through delaying crystallization.Moreover,this-CF_(3) forms a hydrophobic barrier on the surface of the perovskite to prevent cell decomposition.Consequently,the performance of the perovskite solar cells is remarkably improved with the efficiency increased from 18.00% to 20.24%.The perovskite solar cells with multifunctional molecular maintaining 93% of their original efficiency for over 30 days(-55%humidity)in air without device encapsulation,exhibiting a high long-term stability.Moreover,the lead leakage issue of perovskite solar cells has also been suppressed by the built-in 4TA molecule,which is beneficial to environment-friendly application.Ultimately,we believe this multifunctional small molecule provides an available way to achieve high performance perovskite solar cells and the related design strategy is helpful to further develop more versatile materials for perovskite-based optoelectronic devices.

In situ fluorinated solid electrolyte interphase towards long-life lithium metal anodes

The urgent demands for high-energy-density rechargeable batteries promote a flourishing development of Li metal anode.However,the uncontrollable dendrites growth and serious side reactions severely lirmit its commercial application.Herein,an artificial LiF-rich solid electrolyte interphase(SEl)is constructed at molecular-level using one-step photopolymerization of hexafluorobutyl acrylate based solution,where the LiF is in situ generated during photopolymerization process(denoted as PHALF).The LiF-rich layercomprised flexible polymer matrix and inorganic LiF filler not only ensures intimate contact with Li anode and adapts volume fluctuations during cycling but also regulates Li deposition behavior,enabling it to suppress the dendrite growth and block side reactions between the electrolyte and Li metal.Accordingly,the PHALF-Li anode presents superior stable cycling performance over 500 h at 1 mA·cm^-2 for 1 mA·h·cm^-2 without dendrites growth in carbonate electrolyte.The work provides a novel approach to design and build in situ artificial SEl layer for high-safety and stable Li metal anodes.

Magnetically separated and N, S co-doped mesoporous carbon microspheres for the removal of mercury ions

Magnetically separated and N, S co-doped mesoporous carbon microspheres （NIS-MCMs/Fe304） are fabricated by encapsulating Si02 nanoparticles within N, S-containing polymer microspheres which were prepared using resorcinol/formaldehyde as the carbon source and cysteine as the nitrogen and sulfur co-precursors, followed by the carbonization process, silica template removal, and the introduction of Fe3O4 into the carbon mesopores. N/S-MCMs/Fe3O4 exhibits an enhanced Hg2＋ adsorption capacity of 74.5 rag/g, and the adsorbent can be conveniently and rapidly separated from wastewater using an external magnetic field. This study opens up new opportunities to synthesize well- developed, carbon-based materials as an adsorbent for potential applications in the removal of mercury ions from wastewater.

Highly active N,O-doped hierarchical porous carbons for high-energy supercapacitors

Highly active N,O-doped hierarchical porous carbons(NOCs)are fabricated through the in-situ polymerization and pyrolysis of o-tolidine and p-benzoquinone.As-prepared NOCs have a variety of faradaic-active species(N-6,N-5 and O-I),high ion-accessible platform(1799 m^2/g)and hierarchically micro-meso-macro porous architecture.Consequently,the resultant NOC electrode delivers an advantageous specific capacitance(311 F/g),with a pseudocapacitive contribution of 37%in a threeelectrode configuration,and an enhanced energy output of 18.0 Wh/kg@350 W/kg owing to the enlarged faradaic effect in an aqueous redox-active cell.Besides,a competitive energy density(74.9 Wh/kg)and high-potential durability(87.8%)are achieved in an ionic liquid(EMIMB F4)-assembled device.This study sheds light on a straightforward avenue to optimize the faradaic activity and nanoarchitecture for advanced supercapacitors.

Synthesis of MnO2/N-doped ultramicroporous carbon nanospheres for high-performance supercapacitor electrodes

We demonstrate a simple and highly efficient strategy to synthesize MnO2/nitrogen-doped ultramicroporous carbon nanospheres（MnO2/N-UCNs） for supercapacitor application.MnO2/N-UCNs were fabricated via a template-free polymerization of resorcinol/formaldehyde on the surface of phloroglucinol/terephthalaldehyde colloids in the presence of hexamethylenetetramine,followed by carbonization and then a redox reaction between carbons and KMnO4.As-prepared MnO2/N-UCNs exhibits regular ultramicropores,high surface area,nitrogen heteroatom,and high content of MnO2.A typical MnO2/N-UCNs with 57 wt.%MnO2 doping content（denoted as MnO2（57%）/N-UCNs） makes the most use of the synergistic effect between carbons and metal oxides.MnO2（57%）/N-UCNs as a supercapacitor electrode exhibits excellent electrochemical performance such as a high specific capacitance（401 F/g at 1.0 A/g） and excellent charge/discharge stability（86.3%of the initial capacitance after 10,000 cycles at 2.0 A/g） in 1.0 mol/L Na2SO4 electrolyte.The well-designed and high-performance MnO2/N-UCNs highlight the great potential for advanced supercapacitor applications.

Zinc tartrate oriented hydrothermal synthesis of microporous carbons for high performance supercapacitor electrodes

A novel zinc tartrate oriented hydrothermal synthesis of microporous carbons was reported. Zinc–organic complex obtained via a simple chelation reaction of zinc ions and tartaric acid is introduced into the networks of resorcinol/formaldehyde polymer under hydrothermal condition. After carbonization process, the resultant microporous carbons achieve high surface area（up to 1255 m^2/g） and large mean pore size（1.99 nm） which guarantee both high specific capacitance（225 F/g at 1.0 A/g） and fast charge/discharge operation（20 A/g） when used as a supercapacitor electrode. Besides, the carbon electrode shows good cycling stability, with 93% capacitance retention at 1.0 A/g after 1000 cycles. The welldesigned and high-performance microporous carbons provide important prospects for supercapacitor applications.

High-energy aqueous supercapacitors enabled by N/O codoped carbon nanosheets and“water-in-salt”electrolyte

A facile fabrication strategy is reported to obtain N/O codoped porous carbon nanosheets for pur-pose of ameliorating the charge transfer and accumulation in the concentrated LiTFSI(lithium bis(trifluoromethane sulfonyl)imide)electrolyte.By tunning the feed ratio of comonomers,the porous nanosheet structure is endowed with a significant ion-adsorption surface area(1630 m^(2)/g)and intercon-nected hierarchical porosity;meanwhile,high-level N/O dopants(N:3.58 at%,O:12.91 at%)increase the effective contact area for electrolyte ions,and further facilitate rapid ion/electron transfer.Benefiting from the advantageous features,carbon nanosheets electrode reveal an enhanced specific capacitance(375 F/g)in three-electrode configuration and the H_(2)SO_(4)-based device yields a high gravimetric energy density of 11.4 Wh/kg.Particularly,the ion-diffusion highways in porous carbon nanosheets contribute to the 2.25 V LiTFSI-based symmetric device with a high energy delivery up to 33.1 Wh/kg.This work offers an in-spiring strategy for facile fabrication of carbon nanosheets,and demonstrates their promising application in“water-in-salt”electrolyte-based supercapacitor systems.