Electro-chemo-mechanical analysis of the effect of bending deformation on the interface of flexible solid-state battery

Flexible solid-state battery has several unique characteristics including high flexibility,easy portability,and high safety,which may have broad application prospects in new technology products such as rollup displays,power implantable medical devices,and wearable equipments.The interfacial mechanical and electrochemical problems caused by bending deformation,resulting in the battery damage and failure,are particularly interesting.Herein,a fully coupled electro-chemo-mechanical model is developed based on the actual solid-state battery structure.Concentration-dependent material parameters,stress-dependent diffusion,and potential shift are considered.According to four bending forms(k=8/mm,0/mm,-8/mm,and free),the results show that the negative curvature bending is beneficial to reducing the plastic strain during charging/discharging,while the positive curvature is detrimental.However,with respect to the electrochemical performance,the negative curvature bending creates a negative potential shift,which causes the battery to reach the cut-off voltage earlier and results in capacity loss.These results enlighten us that suitable electrode materials and charging strategy can be tailored to reduce plastic deformation and improve battery capacity for different forms of battery bending.

An insight into failure mechanism of NASICON-structured Na3V2（PO4）3 in hybrid aqueous rechargeable battery

NASICON (Na-super-ionic-conductors)-structured materials have attracted extensive research interest due to their great application potential in secondary batteries. However, the mechanism of capacity fading for NASICON-structured electrode materials has been rarely studied. In this paper, we synthesized the NASICON-structured Na3V2(PO4)3/C composite by simple sol-gel and high-temperature solid-phase method and investigated its electrochemical performance in Na-Zn hybrid aqueous rechargeable batteries. After characterizing the structure, morphology and composition variations as well as the interfacial resistance changes of Na3V2(PO4)3/C cathode during cycling, we propose a mechanical and interfacial degradation mechanism for capacity fading of NASICON-structured Na3V2(PO4)3/C in Na-Zn hybrid aqueous rechargeable batteries. This work will shed light on enhancing the mechanical and in terfacial stability of NASICON-structured Na3V2(PO4)3/C in Na-Zn hybrid aqueous rechargeable batteries.

Sn_(4)P_(3)nanoparticles confined in multilayer graphene sheets as a high-performance anode material for potassium-ion batteries

Phosphorus-based anodes are highly promising for potassium-ion batteries(PIBs)because of their large theoretical capacities.Nevertheless,the inferior potassium storage properties caused by the poor electronic conductivity,easy self-aggregation,and huge volumetric changes upon cycling process restrain their practical applications.Now we impregnate Sn_(4)P_(3)nanoparticles within multilayer graphene sheets(Sn_(4)P_(3)/MGS)as the anode material for PIBs,greatly improving its potassium storage performance.Specifically,the graphene sheets can efficiently suppress the aggregation of Sn_(4)P_(3)nanoparticles,enhance the electronic conductivity,and sustain the structural integrity.In addition,plenty of Sn_(4)P_(3)nanoparticles impregnated in MGS offer a large accessible area for the electrolyte,which decreases the diffusion distance for K^(+)and electrons upon K^(+)insertion/extraction,resulting in an improved rate capability.Consequently,the optimized Sn_(4)P_(3)/MGS containing 80 wt%Sn_(4)P_(3)(Sn_(4)P_(3)/MGS-80)exhibits a high reversible capacity of 378.2 and 260.2 m Ah g;at 0.1 and 1 A g^(-1),respectively,and still delivers a large capacity retention of 76.6%after the 1000th cycle at 0.5 A g^(-1).

I/P interface modification for stable and efficient perovskite solar cells

Interface engineering has played an increasingly essential role in the development of perovskite solar cells(PSCs).Herein,we adopted an effective and simple one-step interface passivation method on a FA-based perovskite to fabricate efficient and stable planar PSCs.The surface defects are reduced by the perovskite interface passivation layer incorporated between the hole transport and perovskite absorber layers,and then non-radiative recombination is suppressed while interfacial carrier extraction is enhanced.The passivated planar PSCs demonstrates 20.83%power conversion efficiency(PCE),which is caused by the simultaneous enhancement of the fill factor and open-circuit voltage.In addition,the device also shows great ambient and thermal stability.It retains 94%of its original PCE after 1000 h under ambient air without encapsulation as well as90%of its initial efficiency after 400 h under continuous heating at 65°C with encapsulation.This research provides a strategy for the development of efficient and stable PSCs.

Tin dioxide buffer layer-assisted efficiency and stability of wide-bandgap inverted perovskite solar cells

Inverted perovskite solar cells(IPSCs) have attracted tremendous research interest in recent years due to their applications in perovskite/silicon tandem solar cells. However, further performance improvements and long-term stability issues are the main obstacles that deeply hinder the development of devices. Herein, we demonstrate a facile atomic layer deposition(ALD) processed tin dioxide(SnO2) as an additional buffer layer for efficient and stable wide-bandgap IPSCs. The additional buffer layer increases the shunt resistance and reduces the reverse current saturation density, resulting in the enhancement of efficiency from 19.23% to 21.13%. The target device with a bandgap of 1.63 eV obtains open-circuit voltage of 1.19 V, short circuit current density of 21.86 mA/cm^(2), and fill factor of 81.07%. More importantly, the compact and stable SnO_(2) film invests the IPSCs with superhydrophobicity, thus significantly enhancing the moisture resistance. Eventually, the target device can maintain 90% of its initial efficiency after 600 h storage in ambient conditions with relative humidity of 20%–40% without encapsulation. The ALD-processed SnO_(2) provides a promising way to boost the efficiency and stability of IPSCs, and a great potential for perovskite-based tandem solar cells in the near future.

Composite electron transport layer for efficient N-I-P type monolithic perovskite/silicon tandem solar cells with high open-circuit voltage

Perovskite/silicon tandem solar cells(PSTSCs) have exhibited huge technological potential for breaking the Shockley-Queisser limit of single-junction solar cells. The efficiency of P-I-N type PSTSCs has surpassed the single-junction limit, while the performance of N-I-P type PSTSCs is far below the theoretical value. Here, we developed a composite electron transport layer for N-I-P type monolithic PSTSCs with enhanced open-circuit voltage(VOC) and power conversion efficiency(PCE). Lithium chloride(Li Cl) was added into the tin oxide(SnO_(2)) precursor solution, which simultaneously passivated the defects and increased the electron injection driving force at the electron transfer layer(ETL)/perovskite interface.Eventually, we achieved monolithic PSTSCs with an efficiency of 25.42% and V_(OC) of 1.92 V, which is the highest PCE and VOCin N-I-P type perovskite/Si tandem devices. This work on interface engineering for improving the PCE of monolithic PSTSCs may bring a new hot point about perovskite-based tandem devices.

Highly efficient bifacial semitransparent perovskite solar cells based on molecular doping of CuSCN hole transport layer

Coper thiocyanate(CuSCN)is generally considered as a very hopeful inorganic hole transport material(HTM)in semitransparent perovskite solar cells(ST-PSCs)because of its low parasitic absorption,high inherent stability,and low cost.However,the poor electrical conductivity and low work function of CuSCN lead to the insufficient hole extraction and large open-circuit voltage loss.Here,2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane(F4TCNQ)is employed to improve conductivity of CuSCN and band alignment at the CuSCN/perovskite(PVK)interface.As a result,the average power conversion efficiency(PCE)of PSCs is boosted by≈11%.In addition,benefiting from the superior transparency of p-type CuSCN HTMs,the prepared bifacial semitransparent n-i-p planar PSCs demonstrate a maximum efficiency of 14.8%and 12.5%by the illumination from the front side and back side,respectively.We believe that this developed CuSCN-based ST-PSCs will promote practical applications in building integrated photovoltaics and tandem solar cells.

High area-capacity Mg batteries enabled by sulfur/copper integrated cathode design

Rechargeable Mg batteries potentially display lower cost and competitive energy density compared with their Li-ion counterparts.However,the practical implementation of high area-capacity cathodes still remains a formidably challenging task.This work presents the sulfur/copper integrated cathodes fabricated by the conventional blade-coating process and slurry-dipping method.The sulfur/copper foil integrated cathodes deliver a high area-capacity of 2.6 mAh cm^(-2)after 40 cycles,while the sulfur/copperfoam integrated cathode exhibits an ultrahigh area-capacity of 35.4 mAh cm^(-2),corresponding to 743.1 Wh L^(-1)at the electrode level(1.5 times higher than the LiCoO_(2)-graphite system).The in-situ formed copper sulfide intermediates with sufficient cation defects can act as functional intermediates to regulate the sulfur electrochemistry during the first discharge process.The subsequent cycles are operated by the reversible displacement reaction between Mg-ions and copper sulfide active substances.In particular,the copper ions prefer to extrude along the[001]direction in copper sulfides lattice and simultaneously the rock-salt MgS crystals are generated.Besides,the nonuniform surface topography of the cycled Mgmetal anode,caused by the spatial inhomogeneity in current distribution,is demonstrated to lead to the battery performance degradation for high area-capacity Mg batteries.

A Weighted Combination Forecasting Model for Power Load Based on Forecasting Model Selection and Fuzzy Scale Joint Evaluation

To solve the medium and long term power load forecasting problem,the combination forecasting method is further expanded and a weighted combination forecasting model for power load is put forward.This model is divided into two stages which are forecasting model selection and weighted combination forecasting.Based on Markov chain conversion and cloud model,the forecasting model selection is implanted and several outstanding models are selected for the combination forecasting.For the weighted combination forecasting,a fuzzy scale joint evaluation method is proposed to determine the weight of selected forecasting model.The percentage error and mean absolute percentage error of weighted combination forecasting result of the power consumption in a certain area of China are 0.7439%and 0.3198%,respectively,while the maximum values of these two indexes of single forecasting models are 5.2278%and 1.9497%.It shows that the forecasting indexes of proposed model are improved significantly compared with the single forecasting models.

Quantum Corrections on Tunneling Radiation by the Generalized Uncertainty Principle

Based on the generalized uncertainty principle (GUP), the researchers find that the quantum gravity affects the Klein-Gordon equation exactly. Hence, the Klein-Gordon equation which is corrected by GUP will be more suitable on the expression of the tunneling behavior. Then, the corrected Hawking temperature of the GHS black hole is obtained. After analyzing this result, we find out that the Hawking temperature is not only related to the mass of black hole, but also related to the mass and energy of outgoing fermions. Finally, we infer that the Hawking radiation will be stopped, and the remnants of black holes exist naturally.

From lighting-ferroelectric to photovoltaic properties of Pb(Zr,Ti)O_3(PZT) thin film with symmetric/asymmetric interface energy barrier

Recently,ferroelectric(FE)materials have been intensively investigated for photovoltaic(PV)applications due to the existence of internal polarization field which acts as a drive force to separate electron-hole pair.Lead zirconate titanate,Pb(Zr,Ti)O3(PZT),as one of the most commonly used ferroelectric materials,has been extensively studied

Thinner 2D α-MoO_(3) makes setting up memristors easier

Two-dimensional(2D)metal oxide α-MoO_(3) shows great potentials because of its very high dielectric constant,air stability and anisotropic phonon polaritons.However,a method to produce ultrathin single crystallineα-MoO3 with high transferability for functional device architecture is lacking.Herein,we report on the controllable synthesis of ultrathinα-MoO_(3) single crystals via chemical vapor deposition(CVD)assisted by plasma pretreatment.We also carried out systematic computational work to explicate the mechanism for the slantly-oriented growth of thin nanosheets on plasma-pretreated substrate.The method possesses certain universality to synthesize other ultrathin oxide materials,such as Bi_(2)O_(3) and Sb_(2)O_(3) nanosheets.As-grownα-MoO_(3) presents a high dielectric constant(≈40),ultrathin thickness(≈3 nm)and high transferability.Memristors withα-MoO_(3) as the functional layers show excellent performance featuring high on/off ratio of approximately 104,much lower set voltage around 0.5 V,and highly repetitive voltage sweep endurance.The power consumption of MoO_(3) memristors is significantly reduced,resulted from reduced thickness of the MoO_(3) nanosheets.Single crystal ultrathinα-MoO3 shows great potentials in post-Moore memristor and the synthesis of CVD assisted by plasma pretreatment approach points to a new route for materials growth.

Multidimensional regulation of Ti-Zr-Cr-Mn hydrogen storage alloys via Y partial substitution

High density and safe storage of hydrogen are the preconditions for the large-scale application of hydrogen energy.Herein,the hydrogen storage properties of Ti_(0.6)Zr_(0.4)Cr_(0.6)Mn_(1.4) alloys are systematically studied by introducing Y element instead of Ti element through vacuum arc melting.After the partial substitution of Y,a second phase of rare earth oxide is added in addition to the main suction hydrogen phase,C14 Laves phase.Thanks to the unique properties of rare earth elements,the partial substitution of Y can not only improve the activation properties and plateau pressure of the alloys,but also increase the effective hydrogen storage capacity of the alloys.The comprehensive properties of hydrogen storage alloys are improved by multidimensional regulation of rare earth elements.Among them,Ti_(0.552)Y_(0.048)Zr_(0.4)Cr_(0.6)Mn_(1.4) has the best comprehensive performance.The alloy can absorb hydrogen without activation at room temperature and 5 MPa,with a maximum hydrogen storage capacity of 1.98 wt.%.At the same time,it reduces the stability of the hydride and the enthalpy change value,making it easier to release hydrogen.Through theoretical analysis and first-principle simulation,the results show that the substitution of Y element reduces the migration energy barrier of hydrogen and the structural stability of the system,which is conducive to hydrogen evolution.The alloy has superior durability compared to the original alloy,and the capacity retention rate was 96.79%after 100 hydrogen absorption/desorption cycles.

Electrochemical activation of oxygen atom of SnO2 to expedite efficient conversion reaction for alkaline-ion(Li+/Na+/K+)storages

SnO2-based anode materials have attracted much attention due to high capacity and relatively mild voltage platforms.However,limited by low initial Coulombic efficiency(ICE)and poor stability,its practical application is still challenging.Recently,it has been found that compositing carbon or metal particles with SnO2 is an effective strategy to achieve high alkaline-ion storages.Although this strategy may improve the kinetics and ICE of the electrochemical reaction,the specific mechanism has not been clearly elucidated.In this work,we found that the invalidation SnO2 may go through two steps:1)the conversion process from SnO2 to Sn and Li2O;2)the collapse of the electrode material resulted from huge volume changes during the alloyed Sn with alkaline ions.To address these issues,a unique robust Co-NC shell derived from ZIF-67 is introduced,in which the transited metallic Co nanoparticles could accelerate the decomposition of Sn-O and Li-O bonds,thus expedite the kinetics of conversion reaction.As a result,the SnO2@Co-NC electrode achieves a more complete and efficient transfer between SnO2 and Sn phases,possessing a potential to achieve high alkaline-ion(Li+/Na+/K+)storages.

Integrated sensor based on acoustics-electricity-mechanics coupling effect for wireless passive gas detection

Integrated sensor combines multiple sensor functions into a single unit,which has the advantages of miniaturization and better application potential.However,limited by the sensing platforms of the sensor and the selectivity of the sensitive film,there are still challenges to realize multi-component gas detection in one unit.Herein,a principle integration method is proposed to achieve the multi-component gas detection based on the acoustics-electricity-mechanics coupling effect.The electrical and mechanical properties of the Bi_(2)S_(3)nanobelts materials in different atmospheres indicate the possibility of realizing the principle integration.At the same time,the surface acoustic wave(SAW)sensor as a multivariable physical transducer can sense both electrical and mechanical properties.Upon exposure to 10 ppm NO_(2),NH_(3),and their mixtures,the integrated SAW gas sensor shows a 4.5 kHz positive frequency shift(acoustoelectric effect),an 11 kHz negative frequency shift(mechanics effects),and a reduced 4 kHz negative frequency shift(acoustics-electricity-mechanics coupling effect),respectively.Moreover,we realize wireless passive detection of NO_(2)and NH_(3)based on the SAW sensor.Our work provides valuable insights that can serve as a guide to the design and fabrication of single sensors offering multi-component gas detection via different gas sensing mechanisms.

Novel Zr-doped β-Li_(3)PS_(4) solid electrolyte for all-solid-state lithium batteries with a combined experimental and computational approach

All-solid-state lithium batteries(ASSLBs)are promising for safety and high-energy-density large-scale energy storage.In this contribution,we propose a Li_(3–4x)Zr_(x)PS_(4)(LZPS)by Zr-dopedβ-Li_(3)PS_(4)(LPS)as a novel solid electrolyte(SE)for ASSLBs based on experimental and simulation methods.The structure,electronic property,mechanical property,and ionic transport properties of LZPS(x=0,0.03,0.06,and 0.1)are investigated with first-principles calculations.Meanwhile,LZPS is prepared by solid states reaction method.By combining experimental analysis and first-principles calculations,it is confirmed that a small amount of Zr4+can be successfully doped into the framework ofβ-LPS composites without significantly compromising structural integrity.When the Zr^(4+)concentration is x=0.03,the doped material Li_(2.88)Zr_(0.03)PS_(4)exhibits the highest ionic conductivity(5.1×10^(−4)S·cm^(−1))at 30℃,and the Li-ion migration energy barrier is the lowest.The Li_(2.88)Zr_(0.03)PS_(4)SE has obtained the best mechanical properties,the good ductility,and shear deformation resistance,which can better maintain the structural stability of the battery.In addition,the Li/Li symmetrical cell is assembled,which shows excellent electrochemical stability of electrolyte against lithium.The constructed all-solid-state batteries(LiCoO_(2)-Li_(6)PS_(5)Cl|Li_(2.88)Zr_(0.03)PS_(4)|Li-In)delivers an initial discharge capacity of 130.4 mAh·g^(−1)at 0.2 C and a capacity retention of 85.1%after 100 cycles at room temperature.This study provides a promising electrolyte for the application of ASSLBs with high ionic conductivity and excellent stability against lithium.

Identification of lipid droplets in gut bacteria

Dear Editor,The field of gut microbiota is progressing rapidly and thus,appellations like the last human organ,a separate organ,a forgotten organ,and a new organ have been applied to gut microbiota to emphasize its vital functions in our body(Chang and Kao,2019).Gut microbiota has been shown to play a central role in the regulation of human lipid metabolism and be associated with lipid metabolism disorders when aberrant,through composition and microbial metabolites.

Computer vision meets microfluidics: a label-free method for high-throughput cell analysis

In this paper,we review the integration of microfluidic chips and computer vision,which has great potential to advance research in the life sciences and biology,particularly in the analysis of cell imaging data.Microfluidic chips enable the generation of large amounts of visual data at the single-cell level,while computer vision techniques can rapidly process and analyze these data to extract valuable information about cellular health and function.One of the key advantages of this integrative approach is that it allows for noninvasive and low-damage cellular characterization,which is important for studying delicate or fragile microbial cells.The use of microfluidic chips provides a highly controlled environment for cell growth and manipulation,minimizes experimental variability and improves the accuracy of data analysis.Computer vision can be used to recognize and analyze target species within heterogeneous microbial populations,which is important for understanding the physiological status of cells in complex biological systems.As hardware and artificial intelligence algorithms continue to improve,computer vision is expected to become an increasingly powerful tool for in situ cell analysis.The use of microelectromechanical devices in combination with microfluidic chips and computer vision could enable the development of label-free,automatic,lowcost,and fast cellular information recognition and the high-throughput analysis of cellular responses to different compounds,for broad applications in fields such as drug discovery,diagnostics,and personalized medicine.

Organic Passivation of Deep Defects in Cu(In,Ga)Se_(2) Film for Geometry-Simplified Compound Solar Cells

Diverse defects in copper indium gallium diselenide solar cells cause nonradiative recombination losses and impair device performance.Here,an organic passivation scheme for surface and grain boundary defects is reported,which employs an organic passivation agent to infiltrate the copper indium gallium diselenide thin films.A transparent conductive passivating(TCP)film is then developed by incorporating metal nanowires into the organic polymer and used in solar cells.The TCP films have a transmittance of more than 90%in the visible and nearinfrared spectra and a sheet resistance of~10.5Ω/sq.This leads to improvements in the open-circuit voltage and the efficiency of the organic passivated solar cells compared with control cells and paves the way for novel approaches to copper indium gallium diselenide defect passivation and possibly other compound solar cells.

Confining ultrafine SnS nanoparticles in hollow multichannel carbon nanofibers for boosting potassium storage properties

SnS has been extensively investigated as a potential anode material in potassium-ion batteries (PIBs) for its high theoretical capacity.Nonetheless,it suffers a limited cyclic lifespan owing to its poor electronic conductivity and huge volume expansion.This work proposed a facile approach where SnS nanocrystals are confined in the walls of hollow multichannel carbon nanofibers (denoted SnS@HMCFs) to tackle the issues above.In contrast to previous studies,impregnated ultrafine SnS nanocrystals in HMCFs compactly can increase the SnS loading number per unit area of the carbon matrix.Furthermore,the unique hollow multichannel carbon nanofibers are used as a robust carrier to uniformly distribute the SnS nanocrystals.This can significantly accelerate K;/electron transport,resulting in large specific capacity,outstanding rate performance,and steady cycling property for PIBs.High reversible capacities of 415.5 mAh g^(-1)at0.1 A g^(-1)after 300 cycles and 245.5 mAh g^(-1)at 1 A g^(-1)after 1000 cycles are retained,suggesting great potential of SnS@HMCFs as a negative electrode material for PIBs.Additionally,when the SnS@HMCF anode is assembled with the KVPO_(4)F cathode,the obtained full cell shows a large discharge capacity of165.3 m Ah g^(-1)after 200 cycles at 0.1 A g^(-1).