High-Performance Na-Ion Storage of S-Doped Porous Carbon Derived from Conjugated Microporous Polymers

Na-ion batteries(NIBs)have attracted considerable attention in recent years owing to the high abundance and low cost of Na.It is well known that S doping can improve the electrochemical performance of carbon materials for NIBs.However,the current methods for S doping in carbons normally involve toxic precursors or rigorous conditions.In this work,we report a creative and facile strategy for preparing S-doped porous carbons(SCs)via the pyrolysis of conjugated microporous polymers(CMPs).Briefly,thiophene-based CMPs served as the precursors and doping sources simultaneously.Simple direct carbonization of CMPs produced S-doped carbon materials with highly porous structures.When used as an anode for NIBs,the SCs exhibited a high reversible capacity of 440 mAh g?1 at 50 mA g?1 after 100 cycles,superior rate capability,and excellent cycling stability(297 mAh g?1 after 1000 cycles at 500 mA g?1),outperforming most S-doped carbon materials reported thus far.The excellent performance of the SCs is attributed to the expanded lattice distance after S doping.Furthermore,we employed ex situ X-ray photoelectron spectroscopy to investigate the electrochemical reaction mechanism of the SCs during sodiation-desodiation,which can highlight the role of doped S for Na-ion storage.

Understanding the improved performance of sulfur-doped interconnected carbon microspheres for Na-ion storage

As one of the low-cost energy storage systems,Na-ion batteries(NIBs)have received tremendous attention.However,the performance of current anode materials still cannot meet the requirements of NIBs.In our work,we obtain sulfur-doped interconnected carbon microspheres(S-CSs)via a simple hydrothermal method and subsequent sulfurizing treatment.Our S-CSs exhibit an ultrahigh reversible capacity of 520 mAh g^(-1) at 100 mA g^(-1) after 50 cycles and an excellent rate capability of 257 mAh g^(-1),even at a high current density of 2 A g^(-1).The density functional theory calculations demonstrate that sulfur doping in carbon favors the adsorption of Na atom during the sodiation process,which is accountable for the performance enhancement.Furthermore,we also utilize operando Raman spectroscopy to analyze the electrochemical reaction of our S-CSs,which further highlights the sulfur doping in improving Na-ion storage performance.

Graphite Anode for Potassium Ion Batteries: Current Status and Perspective

With the increased demand from the storage of renewable energy sources,some safe and inexpensive energy storage technologies instead of Li-ion batteries become urgently needed.Therefore,K-ion batteries(KIBs)have attracted much attention and evolved significant development because of the low price,safety,and similar property compared with Li-ion batteries.Due to the high reversibility,stability,and low potential plateau,graphite becomes a current research focus and is regarded as one of the most promising KIB’s anode materials.In this review,we mainly discuss the electrochemical reaction mechanism of graphite during potassiation-depotassiation process and analyze the effects of electrode/electrolyte interface on graphite for Kion storage.Besides,we summarize several kinds of methods to improve the performance of graphite for KIBs,including the design of graphite structure,selection of appropriate binder,solvent chemistry,and salt chemistry.Meanwhile,a concept of“relative energy density”is raised,which can be more accurate to evaluate the genuine electrochemical performance of graphite anode involving the specific capacity and potential.In addition,we also summarize the considerable challenges to current graphite anode in KIBs and we believe our work will offer alterative solutions to further explore high-performance graphite anode of K-ion storage.

Coordination and interface engineering to boost catalytic property of two-dimensional ZIFs for wearable Zn-air batteries

Metal organic frameworks(MOFs) have been considered as compelling precursor for miscellaneous applications. However, their unsatisfied electrocatalytic performance limits their direct application as electrocatalyst. Herein, by incorporating the cobalt-oxide bonds and polyaniline(PANI) with two-dimension zeolitic imidazolate frameworks(ZIFs), a novel bifunctional catalyst(Co-O-ZIF/PANI) for Zn-air battery was designed based on a facile and eco-friendly method. This Co-O-ZIF/PANI with optimized surface adsorption effect and suitable Co^(3+)/Co^(2+)ratio, exhibits eminent electrocatalytic activity toward both oxygen reduction and evolution reaction. The as-assembled liquid ZABs based on Co-O-ZIF/PANI achieves a remarkable maximum power density of 123.1 m W cm^(-2) and low discharge-charge voltage gap of 0.81 V at 5 m A cm^(-2) for over 300 cycles. Operando Raman spectroscopy reveals that the excellent performance origins from the optimized surface chemisorption property of O_(2) and H_(2)O brought by Co–O bonds and PANI. This work provides a novel prospect to develop efficient MOF derived bifunctional electrocatalysts by optimizing surface chemisorption properties.

In Situ Monitoring the Potassium‑Ion Storage Enhancement in Iron Selenide with Ether‑Based Electrolyte

As one of the promising anode materials,iron selenide has received much attention for potassium-ion batteries(KIBs).Nevertheless,volume expansion and sluggish kinetics of iron selenide result in the poor reversibility and stability during potassiation–depotassiation process.In this work,we develop iron selenide composite matching ether-based electrolyte for KIBs,which presents a reversible specific capacity of 356 mAh g^(−1) at 200 mA g^(−1) after 75 cycles.According to the measurement of mechanical properties,it is found that iron selenide composite also exhibits robust and elastic solid electrolyte interphase layer in ether-based electrolyte,contributing to the improvement in reversibility and stability for KIBs.To further investigate the electrochemical enhancement mechanism of ether-based electrolyte in KIBs,we also utilize in situ visualization technique to monitor the potassiation–depotassiation process.For comparison,iron selenide composite matching carbonate-based electrolyte presents vast morphology change during potassiation–depotassiation process.When changing to ether-based electrolyte,a few minor morphology changes can be observed.This phenomenon indicates an occurrence of homogeneous electrochemical reaction in ether-based electrolyte,which results in a stable performance for potassium-ion(K-ion)storage.We believe that our work will provide a new perspective to visually monitor the potassium-ion storage process and guide the improvement in electrode material performance.

In situ induced cation-vacancies in metal sulfides as dynamic electrocatalyst accelerating polysulfides conversion for Li-S battery

Cation vacancy engineering is considered to be one of the effective methods to solve the issues of shuttling and sluggish redox kinetics of Li PSs owing to the intrinsic tunability of electronic structure.However,cation vacancies are few studied in the Li-S realm due to their complex and rigid preparation methods.In this work,one-step pyrolysis is reported to in situ introduce Fe-vacancies into iron sulfide(Fe_(0.96)S)as a sulfur host.For this host structure,Fe_(0.96)S is first employed as an adsorbent and catalyst in Li-S system.During the carbonization process,a tight contact structure of Fe_(0.96)S crystal and carbon network(Fe_(0.96)S@C)is in situ constructed,and the carbon layer as a conductor provides smooth electrons transfer pathways for redox reactions.Meanwhile,due to the introduction of Fe-vacancies in Fe S crystal,the adsorption capability and catalytic effect for Li PSs have been substantially enhanced.Moreover,the presence of Fe_(0.96)S crystal favors the mobility of electron and diffusion of Li+,which is revealed by the experiments and theoretical calculations.Through synergy respective advantages effect of Fe_(0.96)S and carbon,the Fe_(0.96)S@C-S cathode delivers high-rate capability at 5.0 C and stable long-life performance.Even under a high sulfur loading of 3.5 mg/cm^(2),the durable cyclic stability is still exhibited with the capacity retention of 93%over 400 cycles at 1.0 C,and the coulombic efficiency is≥98%.Noting that this strategy greatly simplifies the synthetic process of currently known cation-vacancy materials and furnishes a universal mentality for designing both divinable and astonishing new cation-vacancy materials.

Insights on the mechanism of Na-ion storage in expanded graphite anode

Currently,Na-ion battery(NIB) has become one of the most potential alternatives for Li-ion batteries due to the safety and low cost.As a promising anode for Na-ion storage,expanded graphite has attracted considerable attention.However,the sodiation-desodiation process is still unclear.In our work,we obtain expanded graphite through slight modified Hummer's method and subsequent thermal treatment,which exhibits excellent cycling stability.Even at a high current density of 1 A g^(-1),our expanded graphite still remains a high reversible capacity of 100 mA h g^(-1) after 2600 cycles.Furthermore,we also investigate the electrochemical mechanism of our expanded graphite for Na-ion storage by operando Raman technique,which illuminate the electrochemical reaction during different sodiation-desodiation processes.

Manipulating Interfacial Stability Via Absorption-Competition Mechanism for Long-Lifespan Zn Anode

The stability of Zn anode in various Znbased energy storage devices is the key problem to be solved.Herein,aromatic aldehyde additives are selected to modulate the interface reactions between the Zn anode and electrolyte.Through comprehensively considering electrochemical measurements,DFT calculations and FEA simulations,novel mechanisms of one kind of aromatic aldehyde,veratraldehyde in inhibiting Zn dendrite/by-products can be obtained.This additive prefers to absorb on the Zn surface than H_(2)O molecules and Zn^(2+),while competes with hydrogen evolution reaction and Zn plating/stripping proces s via redox reactions,thus preventing the decomposition of active H_(2)O near the interface and uncontrollable Zn dendrite growth via a synactic absorption-competition mechanism.As a result,Zn-Zn symmetric cells with the veratraldehyde additive realize an excellent cycling life of 3200 h under 1 mA cm^(-2)/1 mAh cm^(-2)and over 800 h even under 5 mA cm^(-2)/5 mAh cm^(-2).Moreover,Zn-Ti and Zn-MnO_(2)cells with the veratraldehyde additive both obtain elevated performance than that with pure ZnSO_(4)electrolyte.Finally,two more aromatic aldehyde additives are chosen to prove their universality in stabilizing Zn anodes.

Structure and defect dual-engineering of cobalt oxides for lowtemperature Zn-air batteries

The exploration of bifunctional electrocatalysts with high catalytic activity and long-term durability for low-temperature Zn-air batteries(ZABs)is an ongoing challenge.Here,quintet-shelled hollow spheres,P-doped multi-layer Co_(3)O_(4)(PM-Co_(3)O_(4)),with enriched oxygen vacancies are prepared by thermally induced mass relocation and a simple phosphating process.Various advanced characterizations reveal P anion-induced effects on internal electronic structure and local coordination environment.The finite element method elucidates that the complex multi-layer spherical nanostructure is conducive to the transport and diffusion of OH-and O_(2).Benefiting from its unique structural features and abundant oxygen vacancies,the well-designed PM-Co_(3)O_(4) presents small reversible oxygen overpotential for catalyzing oxygen reduction/evolution reactions.Accordingly,the fabricated low-temperature ZABs based on PM-Co_(3)O_(4) as air-cathode exhibit high power density(20.8 mW·cm^(-2))and long-term stability(over 600 cycles)at the ultra-low temperature of-40℃,outperforming state-of-art Pt/C+IrO_(2)-based ZABs.Furthermore,the dynamic evolution mechanism of cobalt oxide catalysts during ZAB operation is elucidated.This work provides a guideline to design efficient electrocatalysts with regulated electronic configurations and exquisite nano-/microstructures for ZABs under extreme working conditions.

Online soft measurement for wastewater treatment system based on hybrid deep learning

The existing automated wastewater treatment control systems encounter challenges such as the utilization of specialized testing instruments, equipment repair complications, high operational costs, substantial operational errors, and low detection accuracy. An effective soft measure model offers a viable approach for real-time monitoring and the development of automated control in the wastewater treatment process. Consequently, a novel hybrid deep learning CNN-BNLSTM-Attention (CBNLSMA) model, which incorporates convolutional neural networks (CNN), bidirectional nested long and short-term memory neural networks (BNLSTM), attention mechanisms (AM), and Tree-structure Parzen Estimators (TPE), has been developed for monitoring effluent water quality during the wastewater treatment process. The CBNLSMA model is divided into four stages: the CNN module for feature extraction and data filtering to expedite operations;the BNLSTM module for temporal data’s temporal information extraction;the AM module for model weight reassignment;and the TPE optimization algorithm for the CBNLSMA model’s hyperparameter search optimization. In comparison with other models (TPE-CNN-BNLSTM, TPE-BNLSTM-AM, TPE-CNN-AM, PSO-CBNLSTMA), the CBNLSMA model reduced the RMSE for effluent COD prediction by 25.4%, decreased the MAPE by 32.9%, and enhanced the R2 by 14.9%. For the effluent SS prediction, the CBNLSMA model reduced the RMSE by 26.4%, the MAPE by 21.0%, and improved the R2 by 35.7% compared to other models. The simulation results demonstrate that the proposed CBNLSMA model holds significant potential for real-time effluent quality monitoring, indicating its high potential for automated control in wastewater treatment processes.

Perovskite-based color camera inspired by human visual cells

There are two primary types of photoreceptor cells in the human eye:cone cells and rod cells that enable color vision and night vision,respectively.Herein,inspired by the function of human visual cells,we develop a high-resolution perovskite-based color camera using a set of narrowband red,green,blue,and broadband white perovskite photodetectors as imaging sensors.The narrowband red,green,and blue perovskite photodetectors with color perceptions mimic long-,medium-,and short-wavelength cones cells to achieve color imaging ability.Also,the broadband white perovskite photodetector with better detectivity mimics rod cells to improve weak-light imaging ability.Our perovskite-based camera,combined with predesigned pattern illumination and image reconstruction technology,is demonstrated with high-resolution color images(up to 256 x 256 pixels)in diffuse mode.This is far beyond previously reported advanced perovskite array image sensors that only work in monochrome transmission mode.This work shows a new approach to bio-inspired cameras and their great potential to strongly mimic the ability of the natural eve.

A review of the development of full cell lithium-ion batteries： The impact of nanostructured anode materials

Lithium-ion batteries have emerged as the best portable energy storage device for the consumer electronics market. Recent progress in the development of lithium- ion batteries has been achieved by the use of selected anode materials, which have driven improvements in performance in terms of capadty, cyclic stability, and rate capability. In this regard, research focusing on the design and electrochemical performance of full cell lithium-ion batteries, utilizing newly developed anode materials, has been widely reported, and great strides in development have been made. Nanostructured anode materials have contributed largely to the development of full cell lithium-ion batteries. With this in mind, we summarize the impact of nanostructured anode materials in the performance of coin cell full lithium-ion batteries. This review also discusses the challenges and prospects of research into full cell lithium-ion batteries.

Recent advances of wearable and flexible piezoresistivity pressure sensor devices and its future prospects

The human skin inspired soft electronic devices have attracted broadly research attention in the past decades as the promising potential applications in health monitoring and diagnosis,robotics,and prosthetics.The soft wearable piezoresistivity pressure sensor is one of the most attractive candidates for the development of advanced electronic skin for its simple mechanism,compact structure,low cost and power energy consumption and ease of signal acquisition and transforms advantages.In this review,we will explore the recent progress and achievements in the field of piezoresistivity pressure sensor,focusing on the fundamentals of the piezoresistivity pressure sensor and the materials related to the devices,including active materials,substrate materials,and electrode materials.Subsequently,the challenges and outlook are discussed.We list several current challenges perspectives on the development of pressure sensors.Several critical topics for the optimization of the sensitivity and working range of sensing devices toward practical applications are discussed.Finally,perspectives on the slip and force vectors sensors,the developing technologies for multi-function and high-resolution sensor systems and signals process technologies are examined to highlight the near future development tendency in piezoresistivity pressure sensor research field.

In situ plasmonic optical fiber detection of the state of charge of supercapacitors for renewable energy storage

In situ and continuous monitoring of electrochemical activity is key to understanding and evaluating the operation mechanism and efficiency of energy storage devices.However,this task remains challenging.For example,the present methods are not capable of providing the real-time information about the state of charge(SOC)of the energy storage devices while in operation.To address this,a novel approach based on an electrochemical surface plasmon resonance(SPR)optical fiber sensor is proposed here.This approach offers the capability of in situ comprehensive monitoring of the electrochemical activity(the electrode potential and the SOC)of supercapacitors(used as an example).The sensor adopted is a tilted fiber Bragg grating imprinted in a commercial single-mode fiber and coated with a nanoscale gold film for high-efficiency SPR excitation.Unlike conventional“bulk”detection methods for electrode activity,our approach targets the“localized”(sub-μm-scale)charge state of the ions adjacent to the electrode interface of supercapacitors by monitoring the properties of the SPR wave on the fiber sensor surface located adjacent to the electrode.A stable and reproducible correlation between the real-time charge–discharge cycles of the supercapacitors and the optical transmission of the optical fiber has been found.Moreover,the method proposed is inherently immune to temperature cross-talk because of the presence of environmentally insensitive reference features in the optical transmission spectrum of the devices.Finally,this particular application is ideally suited to the fundamental qualities of optical fiber sensors,such as their compact size,flexible shape,and remote operation capability,thereby opening the way for other opportunities for electrochemical monitoring in various hard-to-reach spaces and remote environments.

新型CoOOH/(Ti,C)-Fe_2O_3纳米棒光阳极制备及其光电解水性能研究（英文）

本论文利用一种温和的方法合成了CoOOH/(Ti,C)-Fe_2O_3(CTCF)纳米棒光阳极,并对其光电解水性能进行了研究.在可见光照和1.0 V偏压(相对可逆氢电极)条件下,CTCF光阳极产生的光电流密度为1.85 mA cm^(-2),远高于传统的α-Fe_2O_3光阳极的光电流密度.同时,该电极在强碱性电解液中(pH 14)可以保持较长时间的稳定性.

All-inorganic lead-free NiO_(x)/Cs_(3)Bi_(2)Br_(9) perovskite heterojunction photodetectors for ultraviolet multispectral imaging

Bismuth-based perovskites are considered to be promising candidates to substitute the toxic lead-based perovskite in optoelectronics due to their excellent optoelectronic properties,high environmental friendliness,and(moisture,light,and heat)stability.However,there are still few reports about high performance bismuth-based perovskite ultraviolet photodetectors,and is more lacking in ultraviolet imaging demonstration.Herein,we reported a self-powered NiO_(x)/Cs_(3)Bi_(2)Br_(9) heterojunction photodetector with excellent photodetection performance by electrochemical depositing NiOx as the hole transport layer.The optimized NiO_(x)/CsaBi_(2)Brg heterojunction photodetector exhibits excellent ultraviolet detection performance with a fast response speed of 3.04/4.65 ms,wide linear dynamic range of 116.6 dB,decent responsivity of 4.33 mA·W^(-1) at 0 V bias,and high detectivity of 1.3×10^(11) jones.The outstanding performance of the optimized NiO_(x)/Cs_(3)Bi_(2)Br_(9) heterojunction photodetector is enough to meet the high-quality ultraviolet imaging.Therefore,we further integrated the optimized NiO_(x)/Cs_(3)Bi_(2)Br_(9) heterojunction photodetector to the transmission mode ultraviolet multispectral imaging system,achieving admirable imaging results at weak light condition.This work will play a positive role in promoting the development of bismuth-based ultraviolet photodetection and ultraviolet multispectral imaging.

A review of hard carbon anode: Rational design and advanced characterization in potassium ion batteries

K-ion batteries(KIBs)have attracted tremendous attention and seen significant development because of their low price,high operating voltage,and properties similar to those of Li-ion batteries.In the field of development of full batteries,exploring high-performing and low-cost anode materials for K-ion storage is a crucial challenge.Owing to their excellent cost effectiveness,abundant precursors,and environmental benignancy,hard carbons(HCs)are considered promising anode materials for KIBs.As a result,researchers have devoted much effort to quantify the properties and to understand the underlying mechanisms of HC-based anodes.In this review,we mainly introduce the electrochemical reaction mechanism of HCs in KIBs,and summarize approaches to further improve the electrochemical performance in HC-based materials for K-ion storage.In addition,we also highlight some advanced in situ characterization methods for understanding the evolutionary process underlying the potassiation–depotassiation process,which is essential for the directional electrochemical performance optimization of KIBs.Finally,we raise some challenges in developing smart-structured HC anode materials for KIBs,and propose rational design principles and perspectives serving as the guidance for the targeted optimization of HC-based KIBs.

Ultrahigh “Relative Energy Density” and Mass Loading of Carbon Cloth Anodes for K-Ion Batteries

Mass loading and potential plateau are the two most important issues of potassium(K)-ion batteries(KIBs),but they have long been ignored in previous studies.Herein,we report a simple and scalable method to fabricate acidized carbon clothes(A-CC)as high mass loading(13.1 mg cm−2)anode for KIBs,which achieved a reversible areal-specific capacity of 1.81 mAh cm−2 at 0.2 mA cm−2.Besides,we have proposed the concept of“relative energy density”to reasonably evaluate the electrochemical performance of the anode.According to our calculation method,the A-CC electrode exhibited an ultrahigh relative energy density of 46 Wh m−2 in the initial charge process and remained at 40 Wh m−2 after 50 cycles.Furthermore,we performed the operando Raman spectroscopy(ORS)to investigate the K-ion storage mechanism.We believe that our work might provide a new guideline for the evaluation of anode performance,thereby,opening an avenue for the development of commercial anode.

TiO^(2)electron transport bilayer for all-inorganic perovskite photodetectors with remarkably improved UV stability toward imaging applications

High ultraviolet(UV)stability and low dark current(Idark)are necessary for high-quality perovskite photodetectors(PDs).TiO^(2)thin film is known as effective electron-transport-layer(ETL)for perovskite devices.However,common spin-coated TiO^(2)ETLs endow many surface defects and have strong UV photocatalytic effect to decompose perovskite materials,resulting in inferior stability of devices.In this work,TiO^(2)bilayer film(Bi-TiO^(2))has been fabricated by combining spin-coating and atomic-layer-deposition process and its positive effects on UV stability and Idarkof Cs2 AgBiBr6-based PDs have been revealed for the first time.It is demonstrated that Bi-TiO^(2)possesses fewer surface defects and smoother morphology with type II band alignment,which is beneficial to suppress photocatalytic activity of TiO^(2)and reduce carrier recombination at the interface.After accelerated strong UV aging treatment,the PD with Bi-TiO^(2)maintains excellent performance,whereas the PD with spin-coated TiO^(2)film dramatically deteriorate with on-off ratio drops from~102 to~2.Besides,the Idarkof PD remarkably decreases from~10^(-8) A to~10^(-10) A after bilayer optimization.Furthermore,we have integrated the corresponding PDs into a self-built imaging system adopting diffuse reflection mode.This work suggests a feasible approach to fabricate TiO^(2)/Cs2 AgBiBr6-based PDs with remarkable UV tolerance for imaging applications.

Spectrum-shaped Si-perovskite hybrid photodetectors for hyperspectral bioimaging

Hyperspectral imaging(HSI)with rich spectral and spatial information holds potential for applications ranging from remote sensing to biomedicine.However,charge-coupled device(CCD)detectors used in conventional HSI systems suffer from inferior and unbalanced responsivity in the visible region,which is not a perfect choice for high-performance visible HSI.That is,conventional Si-based CCDs exhibit poor responsivity at short wavelengths(e.g.,400–600 nm)compared with that at longer wavelengths due to the nature of the indirect bandgap in silicon of around 1.1 e V.To solve this challenge,we introduce a Cs Pb Br_(3) perovskite layer to shape the spectrum of a Si/PEDOT:PSS heterojunction photodetector(PD),resulting in a fabricated Si-Cs Pb Br_(3) hybrid PD with enhanced responsivity at 400–600 nm.This results in an approximately flat spectral responsivity curve in the visible region(400–800 nm).Therefore,the stable Si-Cs Pb Br_(3) hybrid PD with a flat spectrum overcomes the shortcomings of traditional Si-based PDs and makes it more suitable for HSI.Further,we set up a first perovskite HSI system with high spectrum resolution and demonstrate potential applications for tumor detection and tissue identification.We believe that this perovskite optimization can be integrated into modern CCD,thus becoming a step in future CCD fabrication processes,which is a milestone for high-performance HSI systems.