Carbon foam with microporous structure for high performance symmetric potassium dual-ion capacitor

A novel carbon foam with microporous structure(CFMS),with the advantages of a simple fabrication process,low energy consumption,large specific surface area and high conductivity,has been prepared by a facile one-step carbonization.In addition,the carbon foam possesses suitable interlayer spacing in short range which is flexible to accommodate the deformation of carbon layer caused by the ion insertion and deinsertion at the charge and discharge state.Furthermore,a low cost carbon-based symmetric potassium dual-ion capacitor(PDIC),which integrates the virtues of potassium ion capacitors and dual-ion batteries,is successfully established with CFMS as both the battery-type cathode and the capacitor-type anode.PDIC displays a superior rate performance,an ultra-long cycle life(90%retention after 10000 cycles),and a high power density of 7800 W kg^-1 at an energy density of 39Whkg^-1.The PDIC also exhibits excellent ultrafast charge and slow discharge properties,with a full charge in just 60 s and a discharge time of more than 3000 s.

Cross-Linked Hollow Graphitic Carbon as Low-Cost and High-Performance Anode for Potassium Ion Batteries

Large-scale and low-cost preparation of carbon-based potassium anode with long life and high capacity is one of the footstones for the development of potassium ion batteries(PIBs).Herein,a low-cost carbon-based material,cross-linked hollow graphitic carbon(HGC),is large scale synthesized to apply for PIBs anode.Its hollow structure can afford sufficient space to overcome the damage caused by the volume expansion of graphitic carbon(GC).While the cross-linked structure forms a compact interconnection network that allows electrons to rapid transfer between different GC frameworks.Electrochemical measurements demonstrated that the HGC anode exhibited low charge/discharge plateau(about 0.25 V and 0.1 V)and excellent specific capacity as high as 298 m A h g^(-1)at the current density of 50 m A g^(-1).And more important,after 200 cycles the capacity of HGC anode still shows 269 m A h g^(-1)(the decay rate of per cycle is only 0.048%).Meanwhile,the use of commercial traditional electrolyte(KPF_(6))and cheap raw materials that provide new hope for trying and realizing the large-scale production of PIBs based on carbon anode materials.

Industrial-Scale Polypropylene–Polyethylene Physical Alloying Toward Recycling

Polypropylene(PP)and polyethylene(PE)play central roles in our daily life.However,their immiscibility presents a major hurdle in both industry and academia when recycling them into alloys with favorable mechanical properties.Moreover,typical compatibilizer-enabled approaches are limited due to increased environmental concerns.Herein,inspired by a traditional Chinese technique,we report a facile,industry-scale methodology that produces a PP/PE binary blend with a highly ordered honeycomb nanostructure without any additives.Due to its nanostructure,the blend exhibits enhanced tensile properties in com-parison with the parent components or with a sample prepared using an internal mixer.This approach has potential for applications not only in immiscible polymer blending,but also in non-sorting,compatibilizer-free waste plastics recycling.Through this technique,we expect that an environmentally friendly and sustainable plastic wastes recycling avenue can be found,and great economic benefits can be gained.

Designing g-C_(3)N_(4)/N-Rich Carbon Fiber Composites for High-Performance Potassium-Ion Hybrid Capacitors

Potassium-based energy storage devices(PEDS)are considered as hopeful candidates for energy storage applications because of the abundant potassium resources in nature and high mobility in the electrolyte.although carbon materials show great potential for potassium-ion storage,poor rate performance,and unsatisfactory cycle lifespan in existing carbon-based PIBs anode,it also cannot match the dynamics and stability of the capacitor cathode.Nitrogen doping has been proven to be a effective modification strategy to improve the electrochemical performance of carbon materials.Hence,we prepare carbon nanofibers and g-C_(3)N_(4)composites with high nitrogen contents(19.78 at%);moreover,the sum of pyrrolic N and pyridinic N is up to 59.51%.It achieves high discharge capacity(391 m Ah g^(-1)at0.05 A g^(-1)),rate capacity(141 m Ah g^(-1)at 2 A g^(-1)),and long cycling performance(201 m Ah g^(-1)at 1 A g^(-1)over 3000 cycles)when as an anode for PIBs.Furthermore,it can deliver promising discharge capacity of132 m Ah g^(-1)at 0℃.Moreover,as battery anode for potassium-ion hybrid capacitors(PIHC)device with an active carbon cathode,it delivers energy/power density(62 and 2102 W kg^(-1))as well as high reversible capacity(106 m Ah g^(-1)at 1 A g^(-1)).

Superstable potassium metal batteries with a controllable internal electric field

Stable potassium metal batteries(PMBs)are promising candidates for electrical energy storage due to their ability to reversibly store electrical energy at a low cost.However,dendritic growth and large volume changes hinder their practical application.Here,referring to the morphology and structure of a virus,a bionic virus-like-carbon microsphere(BVC)was designed as the anode host for a PMB.A BVC with a three-dimensional structure can not only control the electric field,which can suppress dendrite formation,but can also provide a larger space to accommodate the volume change during the cycle progress.The designed potassium(K)metal anode exhibits excellent cycle life and stability(during 1800 h of repeated plating/stripping of K at a current density of 0.1 mA cm−2,K-BVC can realize a very stable K metal anode with low voltage hysteresis).Stable cyclability and improved rate capability can be realized in a full cell using Prussian blue over 400 cycles.This research provides a new idea for the development of stable K metal anodes and may pave the way for the practical application of next-generation metal batteries.

Validation of the Nanjing Criteria for Diagnosing Pyrrolizidine Alkaloids-induced Hepatic Sinusoidal Obstruction Syndrome

Background and Aims:Hepatic sinusoidal obstruction syndrome(HSOS)is caused by toxic injury to sinusoidal endothelial cells in the liver.The intake of pyrrolizidine alkaloids(PAs)in some Chinese herbal remedies/plants remains the major etiology for HSOS in China.Recently,new diagnostic criteria for PA-induced HSOS(i.e.PA-HSOS)have been developed;however,the efficacy has not been clinically validated.This study aimed to assess the performance of the Nanjing criteria for PA-HSOS.Methods:Data obtained from consecutive patients in multiple hospitals,which included 86 PA-HSOS patients and 327 patients with other liver diseases,were retrospectively analyzed.Then,the diagnostic performance of the Nanjing criteria and simplified Nanjing criteria were evaluated and validated.The study is registered in www.chictr.org.cn(ID:ChiCTR1900020784).Results:The Nanjing criteria have a sensitivity and specificity of 95.35%and 100%,respectively,while the simplified Nanjing criteria have a sensitivity and specificity of 96.51%and 96.33%,respectively,for the diagnosis of PA-HSOS.Notably,a proportion of patients with Budd-Chiari syndrome(11/49)was misdiagnosed as PA-HSOS on the basis of the simplified Nanjing criteria,and this was mainly due to the overlapping features in the enhanced computed tomography/magnetic resonance imaging examinations.Furthermore,most of these patients(10/11)had occlusion or thrombosis of the hepatic vein,and communicating vessels in the liver were found in 8/11 patients,which were absent in PA-HSOS patients.Conclusions:The Nanjing criteria and simplified Nanjing criteria exhibit excellent performance in diagnosing PA-HSOS.Thus,both could be valuable diagnostic tools in clinical practice.

可见光氧化还原催化制备β-硝基酮

β-胺基酮在天然产物和药物合成方面具有极其重要的价值.Mannich反应是合成β-胺基酮的重要方法,但仍然存在局限性:无法合成-NH_(2)未被修饰的β-氨基酮或-NH_(2)连在β-季碳上的酮.本文利用可见光诱导的氧化还原催化,由烯醇三甲基硅醚与偕溴代硝基烃在温和条件下制备各种β-硝基酮,包括硝基连在β-季碳上的酮.这些结构新颖的β-硝基酮很容易转化为β-NH_(2)酮、1,3-氨基醇、α,β-不饱和酮、β-氰基酮和γ-硝基酮.

氮掺杂空心碳纤维用作高性能钾离子电池自支撑负极材料

本文报道了一种具有多级结构(氮掺杂团簇复合中空碳纤维)、高可逆容量的钾离子电池负极材料(NHCF@NCC).该电极材料以多孔氮掺杂中空碳纤维为骨架,具有大比表面积,可有效地缩短钾离子的扩散距离,增加电极材料与电解质的接触界面.另外,附着在中空碳纤维上的不规则的氮掺杂团簇可以提供更多的反应活性位点.由于碳纤维高的纵横比,NHCF@NCC可形成三维连通导电网络的自支撑结构.以NHCF@NCC为自支撑无衬底负极的钾离子电池表现出优异的电化学性能,100 mA g^-1电流密度下可逆容量可达310 mA hg^-1,1000次循环后容量无明显衰减.当电流密度增加到2000 mA g^-1,该自支撑电极仍具有153 mA h g^-1的可逆容量,显示了优异的倍率性能.

Engineering of yolk-shelled FeSe_(2)@nitrogen-doped carbon as advanced cathode for potassium-ion batteries

Potassium-ion batteries(KIBs)have become the most promising alternative to lithium-ion batteries for large-scale energy storage system due to their abundance and low cost.However,previous reports focused on the intercalation-type cathode materials usually showed an inferior capacity,together with a poor cyclic life caused by the repetitive intercalation of large-size K-ions,which hinders their practical application.Here,we combine the strategies of carbon coating,template etching and hydrothermal selenization to prepare yolk-shelled FeSe_(2)@N-doped carbon nanoboxes(FeSe_(2)@C NBs),where the inner highly-crystalline FeSe_(2)clusters are completely surrounded by the self-supported carbon shell.The integrated and highly conductive carbon shell not only provides a fast electron/ion diffusion channel,but also prevents the agglomeration of FeSe_(2)clusters.When evaluated as a conversion-type cathode material for KIBs,the FeSe_(2)@C NBs electrode delivers a relatively high specific capacity of 257 mAh/g at 100 mA/g and potential platform of about 1.6 V,which endow a high energy density of about 411 Wh/kg.Most importantly,by designing a robust host with large internal void space to accommodate the volumetric variation of the inner FeSe_(2)clusters,the battery based on FeSe_(2)@C NBs exhibits ultra-long cycle stability.Specifically,even after 700 cycles at 100 mA/g,a capacity of 221 mAh/g along with an average fading rate of only 0.02%can be retained,which achieves the optimal balance of high specific capacity and long-cycle stability.