Enhanced High-Temperature Energy Storage Performance of All-Organic Composite Dielectric via Constructing Fiber-Re in forced Structure

Optimizing the high-temperature energy storage characteristics of energy storage dielectrics is of great significance for the development of pulsed power devices and power control systems.Selecting a polymer with a higher glass transition temperature(T_(g))as the matrix is one of the effective ways to increase the upper limit of the polymer operating temperature.However,current high-T_(g)polymers have limitations,and it is difficult to meet the demand for high-temperature energy storage dielectrics with only one polymer.For example,polyetherimide has high-energy storage efficiency,but low breakdown strength at high temperatures.Polyimide has high corona resistance,but low high-temperature energy storage efficiency.In this work,combining the advantages of two polymer,a novel high-T_(g)polymer fiber-reinforced microstructure is designed.Polyimide is designed as extremely fine fibers distributed in the composite dielectric,which will facilitate the reduction of high-temperature conductivity loss for polyimide.At the same time,due to the high-temperature resistance and corona resistance of polyimide,the high-temperature breakdown strength of the composite dielectric is enhanced.After the polyimide content with the best high-temperature energy storage characteristics is determined,molecular semiconductors(ITIC)are blended into the polyimide fibers to further improve the high-temperature efficiency.Ultimately,excellent high-temperature energy storage properties are obtained.The 0.25 vol%ITIC-polyimide/polyetherimide composite exhibits high-energy density and high discharge efficiency at 150℃(2.9 J cm^(-3),90%)and 180℃(2.16 J cm^(-3),90%).This work provides a scalable design idea for high-performance all-organic high-temperature energy storage dielectrics.

Construction of all-organic low dielectric polyimide hybrids via synergistic effect between covalent organic framework and cross-linking structure

Polyimide(PI)is a promising electronic packaging material,but it remains challenging to obtain an all-organic PI hybrid film with decreased dielectric constant and loss without modifying the monomer.Herein,a series of allorganic PI hybrid films were successfully prepared by introducing the covalent organic framework(COF),which could induce the formation of the cross-linking structure in the PI matrix.Due to the synergistic effects of the COF fillers and the cross-linking structure,the PI/COF hybrid film containing 2 wt%COF exhibited the lowest dielectric constant of 2.72 and the lowest dielectric loss(tanδ)of 0.0077 at 1 MHz.It is attributed to the intrinsic low dielectric constant of COF and a large number of mesopores within the PI.Besides,the cross-linking network of PI prevents the molecular chains from stacking and improves the fraction of free volume(FFV).The molecular dynamics simulation results are well consistent with the dielectric properties data.Furthermore,the PI/COF hybrid film with 5 wt%COF showed a significant enhancement in breakdown strength,which increased to 412.8 kV/mm as compared with pure PI.In addition,the PI/COF hybrid film achieve to reduce the dielectric constant and thermal expansion coefficient(CTE).It also exhibited excellent thermal,hydrophobicity,and mechanical performance.The all-organic PI/COF hybrid films have great commercial potential as next-generation electronic packaging materials.

An all-organic aqueous potassium dual-ion battery

Benefiting from the environmental friendliness of organic electrodes and the high security of aqueous electrolyte,an all-organic aqueous potassium dual-ion full battery(APDIB) was assembled with 21 M potassium bis(fluoroslufonyl)imide(KFSI) water-in-salt as the electrolyte.The APDIB could deliver a reversible capacity of around 50 mAh g^(-1) at 200 mA g^(-1)(based on the weight of total active materials),a long cycle stability over 900 cycles at 500 mA g^(-1) and a high coulombic efficiency of 98.5%.The reaction mechanism of APDIB during the charge/discharge processes is verified:the FSI-could associate/disassociate with the nitrogen atom in the polytriphenylamine(PTPAn) cathode,while the K^(+) could react with C=O bonds in the 3,4,9,10-perylenetetracarboxylic diimide(PTCDI) anode reversibly.Our work contributes toward the understanding the nature of water-into-salt electrolyte and successfully constructed all-organic APDIB.

A bipolar verdazyl radical for a symmetric all-organic redox flow-type battery

A symmetric all-organic non-aqueous redox flow-type battery was investigated employing the neutral small molecule radical 3-phenyl-1,5-di-p-tolylverdazyl,which can be reversibly oxidized and reduced in one-electron processes,as the sole charge storage material.Cyclic voltammetry of the verdazyl radical in 0.5 M tetrabutylammonium hexa fluoro phosphate(TBAPF6)in acetonitrile revealed redox couples at-0.17 V and-1.15 V vs.Ag+/Ag,leading to a theoretical cell voltage of 0.98 V.From the dependence of peak currents on the square root of the scan rate,diffusion coefficients on the order of 4 x 10 6 cm2 s-1 were demonstrated.Cycling performance was assessed in a static cell employing a Tokoyuma AHA anion exchange membrane,with 0.04 M verdazyl as catholyte and anolyte in 0.5 M TBAPF6 in acetonitrile at a current density of 0.12 mA cm-2.Although coulombic efficiencies were good(94%-97%)throughout the experiment,the capacity faded gradually from high initial values of 93%of the theoretical discharge capacity to 35%by the 50th cycle.Voltage and energy efficiencies were 68%and 65%,respectively.Postcycling analysis by cyclic voltammetry revealed that decomposition of the active material with cycling is a leading cause of cell degradation.

腐蚀抑制剂All-Organic/Molybdate

Dexter公司的Mogul分公司以工业化的规模生产了一种适用于闭路循环冷却和加热体系的新型腐蚀抑制剂.其商品名为All-Or-ganic/Molybdate。这种新型腐蚀抑制剂能消除以铬酸盐、亚硝酸盐、磷酸盐、二氧化硅和肼聚合物为主体的常用抑制剂所伴生的问题。铬酸盐污染环境。

Fully rubbery synaptic transistors made out of all-organic materials for elastic neurological electronic skin

Neurologic function implemented soft organic electronic skin holds promise for wide range of applications,such as skin prosthetics,neurorobot,bioelectronics,human-robotic interaction(HRI),etc.Here,we report the development of a fully rubbery synaptic transistor which consists of all-organic materials,which shows unique synaptic characteristics existing in biological synapses.These synaptic characteristics retained even under mechanical stretch by 30%.We further developed a neurological electronic skin in a fully rubbery format based on two mechanoreceptors(for synaptic potentiation or depression)of pressure-sensitive rubber and an all-organic synaptic transistor.By converting tactile signals into Morse Code,potentiation and depression of excitatory postsynaptic current(EPSC)signals allow the neurological electronic skin on a human forearm to communicate with a robotic hand.The collective studies on the materials,devices,and their characteristics revealed the fundamental aspects and applicability of the all-organic synaptic transistor and the neurological electronic skin.

All-organic composites with strong photoelectric response over a wide spectral range

2-hydroxynaphthylidene-1′-naphthylamine(HNAN) and –NO_(2) modified HNAN(HNAN-NO_(2)) Schiff base compounds were synthesized and exhibited strong visible light absorption(<650 nm). These compounds were added to poly(vinylidene fluoride-trifluoroethylene)(P(VDF-Tr FE))ferroelectric polymer, obtaining composites with high photoelectric response under visible and infrared light. It was found that the modification of HNAN by the nitro group and the poling of the composites under a high electric field can greatly enhance the photoelectric response of the composites. The composites can generate high photovoltages of 1386 and352.7 mV under irradiation with near-infrared light(915 nm)and green light(532 nm). The mechanism of the photoelectric response of the composites under green light was explored and it was found that the response originates mainly from the coupling effect of the photothermal effect of the Schiff base and the pyroelectric effect of the ferroelectric polymer. The composites, which can be utilized as photodetector materials,are promising for next-generation artificial retina applications and the sensing capability of retina can be extended in a wide wavelength range from visible to infrared light.

Ultraviolet‑Irradiated All‑Organic Nanocomposites with Polymer Dots for High‑Temperature Capacitive Energy Storage

Polymer dielectrics capable of operating efficiently at high electric fields and elevated temperatures are urgently demanded by next-generation electronics and electrical power systems.While inorganic fillers have been extensively utilized to improved high-temperature capacitive performance of dielectric polymers,the presence of thermodynamically incompatible organic and inorganic components may lead to concern about the long-term stability and also complicate film processing.Herein,zero-dimensional polymer dots with high electron affinity are introduced into photoactive allyl-containing poly(aryl ether sulfone)to form the all-organic polymer composites for hightemperature capacitive energy storage.Upon ultraviolet irradiation,the crosslinked polymer composites with polymer dots are efficient in suppressing electrical conduction at high electric fields and elevated temperatures,which significantly reduces the high-field energy loss of the composites at 200℃.Accordingly,the ultraviolet-irradiated composite film exhibits a discharged energy density of 4.2 J cm^(−3)at 200℃.Along with outstanding cyclic stability of capacitive performance at 200℃,this work provides a promising class of dielectric materials for robust high-performance all-organic dielectric nanocomposites.

Interwoven Poly(Anthraquinonyl Sulfide)Nanosheets-Decorated Carbon Nanotubes as Core-Sheath Heteroarchitectured Cathodes for Polymer-Based Asymmetrical Full Batteries

Organic redox-active polymers provide promising alternatives to metal-containing inorganic compounds in Li-ion batteries(LIBs),whereas suffer from low actual capacities,poor rate/power capabilities,and inferior cycling stability.Herein,poly(anthraquinonyl sulfide)-coated carbon nanotubes(CNT@PAQS)are readily performed by in situ polymerization to form core-sheath nanostructures.Remarkably,flower-like PAQS nanosheets are interwoven around CNTs to synergistically create robust 3D hierarchical networks with abundant cavities,internal channels,and sufficiently-exposed surfaces/edges,thereby promoting electron transport and making more active sites accessible for electrolytes and guest ions.Apparently,the as-fabricated CNT@PAQS cathode delivers the large reversible capacity(200.5 mAh g^(-1)at 0.05 A g^(-1)),high-rate capability(161.5 mAh g^(-1)at 5.0 A g^(-1)),and impressive cycling stability(retaining 88.0%over 1000 cycles).In addition,an asymmetric full-battery using CNT@PAQS as a cathode and cyclized polyacrylonitrile-encapsulated CNTs as an anode is assembled that delivers a high energy density of 86.3 Wh kg^(-1),and retains 81.3%of initial capacity after 1000 cycles.This work opens up an efficient strategy to combine highly conductive and redox-active phases into core-sheath heterostructures to unlock the barrier of high-rate charge storage.The further integration of two polymer-based electrodes into asymmetric full cells would also consolidate the development of low-cost,sustainable,and powerful batteries.

Enhancing electrochemical performances of small quinone toward lithium and sodium energy storage

Further application of organic quinone cathodes is restricted because they are inherent in poor conductivity and tend to dissolve in aprotic electrolytes.Salinization can work on the strong solubility of quinones.Herein,the ortho-disodium salt of tetrahydroxyquinone(o-Na_(2)THBQ)was selected to promote the electrochemical properties of tetrahydroxyquinone(THBQ).Reduced dissolution of o-Na_(2)THBQ in electrolyte after salinization(replacement of two H with two Na)contributed to enhanced electrochemical performance.In sodium-ion batteries(SIBs)in ester-based electrolyte,o-Na2THBQ cathodes at 50 mA·g^(-1)exhibited a reversible discharge capacity of 107 mAh·g^(-1)after 200 cycles.Ulteriorly,in ether-based electrolyte,reversible discharge capacities of 200.4,102.2,99.5 and 88 mAh·g^(-1)were obtained at 800,1600,3200 and 4800 mA·g^(-1)after 1000,2000,5000 and 8000 cycles,respectively.The ultraviolet absorption spectra and ex situ dissolution experiments of THBQ and o-Na_(2)THBQ showed that o-Na_(2)THBQ hardly dissolved in ether-based electrolyte.In lithium-ion batteries(LIBs),graphene was selected to further enhance the conductivity of o-Na2THBQ.At 50 mA·g^(-1),o-Na_(2)THBQ and o-Na_(2)THBQ/Gr cathodes exhibited reversible discharge capacities of 124 and 131.5 mAh·g^(-1)after 200 cycles in ester-based electrolyte,respectively.At 50 mA·g^(-1),PTPAn/o-Na_(2)THBQ electrodes in an all-organic Na/Li-ion battery showed reversible charge/discharge capacities of 51/50.3 and 33.8/33.1 mAh·g^(-1)after 200 cycles.