Wide Operating Temperature Range Research Articles

Giant electric field-induced second harmonic generation in polar skyrmions

Electric field-induced second harmonic generation allows electrically controlling nonlinear light-matter interactions crucial for emerging integrated photonics applications. Despite its wide presence in materials, the figures-of-merit of electric field-induced second harmonic generation are yet to be elevated to enable novel device functionalities. Here, we show that the polar skyrmions, a topological phase spontaneously formed in PbTiO3/SrTiO3 ferroelectric superlattices, exhibit a high comprehensive electric field-induced second harmonic generation performance. The second-order nonlinear susceptibility and modulation depth, measured under non-resonant 800 nm excitation, reach ~54.2 pm V−1 and ~664% V−1, respectively, and high response bandwidth (higher than 10 MHz), wide operating temperature range (up to ~400 K) and good fatigue resistance (>1010 cycles) are also demonstrated. Through combined in-situ experiments and phase-field simulations, we establish the microscopic links between the exotic polarization configuration and field-induced transition paths of the skyrmions and their electric field-induced second harmonic generation response. Our study not only presents a highly competitive thin-film material ready for constructing on-chip devices, but opens up new avenues of utilizing topological polar structures in the fields of photonics and optoelectronics.

Molecularly Mixed Composite Membranes for Gas Separation Based on Macrocycles Embedded in a Polyimide.

Polyimides are a polymer class that has been extensively investigated as a membrane material for gas separation owing to its interesting permselective properties in a wide range of operation temperatures and pressures. In order to improve their properties, the addition of different filler types is currently studied. p-tert-Butylcalix[n]arene macrocycles (PTBCs) with different cavity sizes (PTBC4, PTBC6, PTBC8) were used as fillers in a commercial thermoplastic polyimide, with a concentration in the range 1-9 wt%, to develop nanocomposite membranes for gas separation. The selected macrocycles are attractive organic compounds owing to their porous structure and affinity with organic polymers. The nanocomposite membranes were prepared in the form of films in which the polymeric matrix is a continuous phase incorporating the dispersed additives. The preparation was carried out according to a pre-mixing approach in a mutual solvent, and the solution casting was followed by a controlled solvent evaporation. The films were characterized by investigating their miscibility, morphology, thermal and spectral properties. The gas transport through these films was examined as a function of the temperature and also time. The results evidenced that the incorporation of the chosen nanoporous fillers can be exploited to enhance molecular transport, offering additional pathways and promoting rearrangements of the polymeric chains.

Two-step strategy to optimize interfacial compatibility of polyether sulfone-Li6.75La3Zr1.75Ta0.25O12 composite polymer electrolytes with Li anode for solid lithium battery with a wide working temperature range

Although composite polymer electrolytes (CPEs) are currently regarded as one of the most promising solid electrolyte systems closing to commercial application, some basic problems, including low conductivity at low temperature, serious interfacial compatibility with Li metal anode, inhibit the development of CPEs for solid state lithium batteries (SSLBs). Herein, a “polymer-in-ceramic” CPEs consisting of polyether sulfone (PESF), Li6·75La3Zr1·75Ta0·25O12 (LLZTO) and bis(trifluoromethane) sulfonimide lithium salt (LiTFSI) is reported, and a two-step strategy is proposed to optimize its conductivity and interfacial compatibility with Li metal anode. Benefitting from both the continuous porous structure to provide additional Li+ conducting pathways on internal porous interfaces and the typical heterogeneous bilayer structure to enhance compatibility with Li metal anode, the optimized CPEs delivers promising Li+ conductivities in a wide operating temperature range (>2.0 × 10−4 S cm−1 at −10 °C, >1.4 × 10−3 S cm−1 at 60 °C), improved tolerance against Li dendrites and/or pulverization. Moreover, commercial LiFePO4 cathode based SSLBs show acceptable discharge specific capacities of >160 mA h g−1 and excellent cycling stabilities of over 200 cycles at both room temperature and 60 °C at 0.2C.

Cyclodextrin incorporated textile supercapacitor/piezo-triboelectric nanogenerator hybrid system for versatile temperature dependent wearable wireless devices

The problem of wearable textile electronics having no power source can be greatly assisted at low-temperature environments by the demand for flexible supercapacitor sustaining self-charging system. We explore a typical piezo-triboelectric nanogenerators (PTNGs) textile fabric integrated flexible supercapacitors (SCs) face substantial difficulty in maintaining their ability to quickly charge in colder environments for various wearable wireless sensing devices. PTNGs using composite electrodes frequently experience quick performance degradation at low energy levels as a result of the poor ion mobility besides charge transfer in the electrolyte. In this article, we offer a SC-coupled self-chargeable power generator with wide operating temperature range (25 ∼ −80 °C). A composite system of sulfonated β-cyclodextrin/polyvinylpyrrolidone/Ni@MnCO3 on cotton fabric with polyvinylidene fluoride and polydimethylsiloxane were used to build the smart textile SC, which produced 19.6 V at −80 °C and exhibited a gravimetric capacitance of 94.7 Fg−1 with excellent cyclic stability (>50,000). The biocompatibility studies reveal good results (∼95 % of cell viability) for the wearable textile SCs. In addition, the possibility of application to a sensing device was successfully demonstrated by connecting the proposed self-driving energy storage complex to a device designed as a wireless circuit. This system can work for seamlessly working for wireless signal transmittance as power source resulting and this system may be able to meet the urgent need for wearable electronics that implanted in the space suit and/or winter clothing needed in harsh climates.

Experimental research on the cooling effect of a novel two-phase closed thermosyphon with semiconductor refrigeration in permafrost regions

Hybrid two-phase closed thermosyphon (TPCT) artificial ground freezing technique is an effective cooling strategy adaptable to different geological and meteorological conditions in permafrost regions. Previous studies have focused on the feasibility of hybrid TPCT with little attention given to the cooling characteristics and long-term effects of this technique under actual environmental conditions. In this study, a novel structured semiconductor refrigeration device, with simple structure, small size, and wide operating temperature range, was designed and manufactured to act as the active condenser of a hybrid TPCT, and the cooling effect of this device was investigated during a two-year field test under stable power supply. This study showed that: 1) The minimum (maximum) average temperature of the semiconductor refrigeration two-phase closed thermosyphon (SRTPCT) evaporator was 0.5 (2.1) °C lower than the TPCT evaporator. The average ground temperature decreased by 0.3 °C, and the permafrost table rose to 0.2 m at 1 m from the evaporators around SRTPCT. The semiconductor refrigeration device added more than 9.75 MJ of cold storage to the soil around the TPCT evaporator during an operating cycle. 2) The optimal working period for the semiconductor refrigeration device was from June to October, and the cooling effect was better when the ambient temperature was low in the warm season. 3) As active condenser of hybrid TPCT in permafrost regions, semiconductor refrigeration device has a larger heat transfer power enhancement for TPCTs than vapor compression refrigeration device in the warm season, and vice versa in the cold season, as well as a higher heat transfer power enhancement for TPCTs than adsorption refrigeration device. The results of this study provide relevant parameters and references for the design and engineering application of future SRTPCT.

Silicon carbide single crystals for high-temperature supercapacitors.

Designing advanced electrode materials that can be reliably cycled at high temperatures and used for assembling advanced energy storage devices remain a major challenge. As a representative of novel wide bandgap semiconductors, silicon carbide (SiC) single crystals have broad prospects in high-temperature energy storage due to their excellent characteristics such as low thermal expansion coefficient, high temperature radiation resistance and stable chemical properties. In this work, an N-type SiC single-crystal material with a high-density porous structure was successfully designed and prepared by using an improved electrochemical anodic oxidation strategy. Besides, the N-type SiC single crystals were used in electrochemical energy storage as an integrated electrode material, exhibiting superior electrochemical performance. In addition, the high-temperature supercapacitor device assembled with ionic liquids has a wide operating temperature range and maintains a capacity of 88.24% after 5000 cycles at 150 °C. The reasons for its high energy storage performance are discussed through electrochemical tests and first-principles calculation methods. This study proves that the application of SiC single crystals in supercapacitor devices has great potential in the field of high-temperature energy storage, providing a reference for the further development of novel semiconductors in the field of energy storage and optoelectronic devices.

Revealing interfacial parasitic reactions of nitrile rubber binders in all-solid-state lithium batteries

The nitrile components in NBR lead to an irreversible side reaction during the initial charging process. However, the problematic chemical stability of NBR has been improved through coordination chemistry, resulting in enhanced battery performance.

Novel propylene carbonate based localized high concentration electrolyte with high voltage, flame retardant and wide temperature characteristics enables excellent electrochemical performances of lithium metal batteries

A novel propylene carbonate based localized high concentration electrolyte using for lithium metal batteries achieves flame retardancy, a broad electrochemical stability window, dendrite-free Li deposition, and a wide operating temperature range.

A Non-Flammable and Flexible Aluminum Derived Lithium-Ion Storage Device with a Wide Temperature Range of Operation.

With the rapid development and increasing popularity of electric vehicles and wearables, battery safety has become a leading focus in the field of energy storage research. Specifically, aluminum-ion batteries are gaining increasing attention as low-cost energy-storage systems with high safety levels and theoretical energy density. However, the dense alumina passivation layer on the aluminum anode surface and slow kinetic performance of commonly used ionic liquid electrolytes still render poor performance. This report presents a new type of aluminum-derived lithium-ion battery (ALIB) that maintains a certain discharge performance under damaging conditions, including continuous bending, high- and low-temperature environments, and shearing. This new ALIB effectively meets the current demand for flexible and wearable batteries. The prepared ALIB achieves a stable cycle of 130 mAh g-1 specific capacity and ≈260Wh kg-1 theoretical energy density at a wide voltage platform of 2V and a test temperature of 25 °C without undergoing combustion. Additionally, the study analyzes the reaction mechanism of this ALIB based on density functional theory and conducts ex situ XRD and XPS analyses to elucidate the underlying storage mechanism.

Humidity-independent gas sensors in the detection of hydrogen sulfide based on Nd2O3-loaded In2O3 porous nanorods

Water vapor greatly interferes with gas sensing characteristics of metal oxide semiconductors (MOS). Consequently, for the first time, Nd2O3-loaded In2O3 porous nanorods were synthesized which exhibited excellent H2S sensitivity along with prominent humidity-independent characteristics, whereas pristine In2O3 without Nd2O3 showed deteriorated H2S sensing features under increasing ambient humid conditions in a wide operating temperature range. The mechanism of humidity-independent H2S sensing properties was researched via X-ray photoelectrons spectroscopy (XPS), in-situ Fourier Transform infrared spectroscopy (in-situ DRIFTS) and the corresponding gas sensing measurements, which is in close relations with the inhibition of chemisorbed oxygen and scavenging hydroxyl groups on In2O3 surface induced by surficial Nd2O3 component. This strategy poses a cutting-edge comprehending of temperature-dependent humidity-interference on MOS, paves a novel route for fabricating H2S sensors with exceptional sensitivity, selectivity and anti-humidity properties, which will be quite conducive for real-time exhaled breath analyses in disease diagnosis.

Organic High-Temperature Synaptic Phototransistors for Energy-Efficient Neuromorphic Computing.

Organic optoelectronic synaptic devices that can reliably operate in high-temperature environments (i.e., beyond 121°C) or remain stable after high-temperature treatments have significant potential in biomedical electronics and bionic robotic engineering. However, it is challenging to acquire this type of organic devices considering the thermal instability of conventional organic materials and the degradation of photoresponse mechanisms at high temperatures. Here, high-temperature synaptic phototransistors (HTSPs) based on thermally stable semiconductor polymer blends as the photosensitive layer are developed, successfully simulating fundamental optical-modulated synaptic characteristics at a wide operating temperature range from room temperature to 220°C. Robust optoelectronic performance can be observed in HTSPs even after experiencing 750 h of the double 85 testing due to the enhanced operational reliability. Using HTSPs, Morse-code optical decoding scheme and the visual object recognition capability are also verified at elevated temperatures. Furthermore, flexible HTSPs are fabricated, demonstrating an ultralow power consumption of 12.3 aJ per synaptic event at a low operating voltage of -0.05mV. Overall, the conundrum of achieving reliable optical-modulated neuromorphic applications while balancing low power consumption can be effectively addressed. This research opens up a simple but effective avenue for the development of high-temperature and energy-efficient wearable optoelectronic devices in neuromorphic computing applications.

Solid-State Polymer Battery: Manufacturing Process and Characterization

Solid-state batteries are a promising technology that could provide higher energy density, better safety, longer cycle life and a wider operating temperature range than current commercial LiBs [1] .The solid electrolyte is the main component of all-solid-state batteries. It can be ceramic, glass, polymer, or a mixture. Solid Polymer Electrolyte (SPEs) have received distinctive attention, especially by industry, owing to their potential advantages such as safety, lightweight, high flexibility, and realistic processability. However, despite fast growing interest in solid-state technology, reports on the scalable production of all-solid-state lithium-ion batteries using electrodes with meaningful areal capacities are rather scarce [2] . Moreover, chemical, and mechanical challenges remain. The intimate contact between the electrode and the solid electrolyte is difficult due its non-infiltrative nature. This lack of intimate contact severely limits the cycling properties [3] . The development of effective strategies to alleviate the issue of physical contact is imperative in the engineering of solid-state batteries [4] .In the frame of SAFELiMOVE (Advanced all Solid stAte saFE Lithium Metal technology tOwards Vehicle Electrification) project, we assemble a solid-state pouch based on lithium metal anode, a solid polymer electrolyte layer and a compatible cathode. In work, we report on a reliable fabrication process of large-scale all-solid-state lithium-ion batteries using cathodes prepared by CIDETEC, lithium anode provided by Hydro-Quebec, polymers provided by CICe, inorganic filler provided by SCHOTT and a solid polymer electrolyte manufactured at SAFT.All-solid-state lithium-ion battery pouch cells have been successfully built with consistent electrochemical performance. Cycling that shows the good performance of those cells and the lesson learned regarding their cycling conditions will be presented. [1] J. Motalli, “A solid future Nature, 526, S96 (2015) [2] Ningxin Zhang et al “Scalable preparation of practical 1Ah all-solid-state lithium-ion batteries cells and their abuse tests”, Journal of Energy Storage 59 (2023) 106547 [3] Li et al.“Atomically Intimate Contact between Solid Electrolytes and Electrodes for Li Batteries” Mater 1, 1001-1016, October 2, 2019. [4] Theodosios Famprikis, Pieremanuele Canepa, James A. Dawson, M. Saiful Islam and Christian Masquelier“Fundamentals of inorganic solid-state electrolytes for batteries” Nature Materials-August 2019. Figure 1

Understanding the Effect of Mechanical Degradation on the Performance of Solid-State Batteries through Particle Simulations

All-solid-state batteries (ASSBs) have garnered significant interest as a promising alternative to conventional lithium-ion batteries, offering improved safety, higher energy density, longer lifespan, faster charging and wider operating temperature range. A key advantage of ASSBs is the use of solid electrolytes (SE), which eliminate the risks associated with flammable liquid electrolytes. However, the complex electrochemical behavior and multi-scale nature of ASSBs pose challenges in designing and optimizing their performance. This study employs Discrete Element Method (DEM) particle-based models to better understand degradation behavior of ASSBs by considering electrochemical reaction, mass and charge transfer, intercalation expansion and material deformationOur simulations were developed in MATLAB and were performed on a half-cell configuration comprising a SE-layer and an anode electrode. The anode electrode was composed of a particle mixture containing active material (AM) and SE. In our simulations, Si was employed as AM, which experiences substantial intercalation expansion during charge cycling 1. Our previously developed DEM model2,3 resolved elastic and plastic deformation of both AM and SE particles which become compressed due to the intercalation expansion. The simulation of intercalation was achieved by integrating the Newman electrochemical model,4 into the DEM mechanical model. Building on our earlier study5, where the Li concentration was resolved within each AM particle, this study is also accounting for the Li-ion potential within each SE particle. Interparticle conduction and diffusion were computed by determining the contact area of AM-AM and SE-SE contacts, which were affected by the compression of the electrode. The electrochemical reaction was calculated at the AM-SE interface using the Butler-Volmer equation, and in addition the influence of compressive stress on the reaction6 was included.Figure 1(a) depicts the Li concentration and Li-ion potential distribution within the half-cell during charging at different states of charge (SOC), while Figure 1(b) provides a 3D view of the distributions at a SOC of 50%. A considerable expansion of the Si anode is evident. The gradients of Li concentration and Li-ion potential signify significant mass and charge transfer resistance during the charging process. Comparing the distribution of the particles, the anode becomes more porous after the first cycle for the same value of SOC. This effect is attributed to the extensive expansion of the Si anode, leading to plastic compression of the SE layer, which becomes more compact after each cycle. The growing porosity diminishes the contact area between particles, ultimately resulting in the degradation of the half-cell's capacity. In addition to SE-layer compaction, this study aims to investigate several degradation mechanisms and their impact on the performance of ASSBs, including the development of shell voids resulting from AM-SE delamination, crack propagation through SE, and fragmentation of AM.The results of this study provide valuable insights into understanding the effect of mechanical degradation on the performance of ASSBs. By improving our understanding of these mechanisms, we can work towards enhancing the durability and lifespan of ASSBs, ultimately contributing to the development of next-generation energy storage systems. Acknowledgment This work was supported by JSPS KAKENHI Grant-in-Aid for Scientific Research on Innovative Areas, “Science on Interfacial Ion Dynamics for Solid State Ionics Devices, Computational & Data Science” (Gp-A03, grant number 19H05815); and MEXT “Program for Promoting Researches on the Supercomputer Fugaku” (Fugaku battery & Fuel Cell Project), grant number JPMXP1020200301. References M. N. Obrovac and L. Christensen, Electrochem. Solid-State Lett., 7, A93 (2004).M. So, G. Inoue, R. Hirate, K. Nunoshita, S. Ishikawa, and Y. Tsuge, J. Electrochem. Soc., 168, 030538 (2021).M. So, G. Inoue, R. Hirate, K. Nunoshita, S. Ishikawa, and Y. Tsuge, Journal of Power Sources, 508, 230344 (2021).J. Newman and K. E. Thomas-Alyea, Electrochemical Systems, 3rd edition., p. 672, Wiley-Interscience, Hoboken, N.J, (2004).M. So, S. Yano, A. Permatasari, T. D. Pham, K. Park, and G. Inoue, Journal of Power Sources, 546, 231956 (2022).G. Bucci, T. Swamy, S. Bishop, B. W. Sheldon, Y.-M. Chiang, and W. C. Carter, J. Electrochem. Soc., 164, A645 (2017). Figure 1

A broad-spectrum gas sensor based on correlated two-dimensional electron gas

Designing a broad-spectrum gas sensor capable of identifying gas components in complex environments, such as mixed atmospheres or extreme temperatures, is a significant concern for various technologies, including energy, geological science, and planetary exploration. The main challenge lies in finding materials that exhibit high chemical stability and wide working temperature range. Materials that amplify signals through non-chemical methods could open up new sensing avenues. Here, we present the discovery of a broad-spectrum gas sensor utilizing correlated two-dimensional electron gas at a delta-doped LaAlO3/SrTiO3 interface with LaFeO3. Our study reveals that a back-gating on this two-dimensional electron gas can induce a non-volatile metal to insulator transition, which consequently can activate the two-dimensional electron gas to sensitively and quantitatively probe very broad gas species, no matter whether they are polar, non-polar, or inert gases. Different gas species cause resistance change at their sublimation or boiling temperature and a well-defined phase transition angle can quantitatively determine their partial pressures. Such unique correlated two-dimensional electron gas sensor is not affected by gas mixtures and maintains a wide operating temperature range. Furthermore, its readout is a simple measurement of electric resistance change, thus providing a very low-cost and high-efficient broad-spectrum sensing technique.

Unveiling the molecular mechanism of 1,3,2-dioxathiolane 2,2-dioxide in a propylene carbonate-based battery electrolyte

Propylene carbonate (PC)-based electrolytes are gaining attention as next-generation electrolytes for use in high-voltage and high-temperature environments due to their superior stability at high voltages and their wide operating temperature range. However, commercialization is challenged by the exfoliation of the graphite anode, which is caused by the co-intercalation of PC. Various additives have been devised to address this issue. 1,3,2-dioxathiolane 2,2-dioxide (DTD) exhibits outstanding capacity retention and lifespan characteristics in lithium-ion batteries in which PC-based electrolytes are used, but a molecular-level understanding of its operating mechanism remains elusive. According to our quantum static and dynamics calculations, the Li+ binding energy of DTD is much lower than that of PC, rendering its coordination ability insufficient to compete with PC. As a result, the neutral DTD does not play a role in favoring the desolvation of PC from the solvation structure. However, DTD is reduced prior to PC and shows a strong reduction tendency accompanied by ring-opening. Based on this, DTD in its anionic form participates in the Li+ solvation sheath through a solvent–additive exchange reaction to promote the desolvation of PC. We reveal that the use of the charges of the oxygen atoms bonded to Li+ ions to interpret the Li+–solvent binding energies is inappropriate. Instead, we suggest the electrostatic potential minimum (ESPMin) as a useful and powerful descriptor. This work provides insights into the molecular characteristics and mechanisms of additives that enable PC-based electrolytes, offering guidance for the development of new additives.

Spin-Polarized Surface Capacitance Effects Enable Fe3 O4 Anode Superior Wide Operation-Temperature Sodium Storage.

Fe3 O4 is widely investigated as an anode for ambient sodium-ion batteries (SIBs), but its electrochemical properties in the wide operation-temperature range have rarely been studied. Herein, the Fe3 O4 nanoparticles, which are well encapsulated by carbon nanolayers, are uniformly dispersed on the graphene basal plane (named Fe3 O4 /C@G) to be used as the anode for SIBs. The existence of graphene can reduce the size of Fe3 O4 /C nanoparticles from 150 to 80nm and greatly boost charge transport capability of electrode, resulting in an obvious size decrease of superparamagnetic Fe nanoparticles generated from the conversion reaction from 5 to 2nm. Importantly, the ultra-small superparamagnetic Fe nanoparticles (≈2nm) can induce a strong spin-polarized surface capacitance effect at operating temperatures ranging from -40 to 60°C, thus achieving highly efficient Na-ion transport and storage in a wide operation-temperature range. Consequently, the Fe3 O4 /C@G anode shows high capacity, excellent fast-charging capability, and cycling stability ranging from -40 to 60°C in half/full cells. This work demonstrates the viability of Fe3 O4 as anode for wide operation-temperature SIBs and reveals that spin-polarized surface capacitance effects can promote Na-ion storage over a wide operation temperature range.

Solid-State Electrolytes and Electrode/Electrolyte Interfaces in Rechargeable Batteries.

Solid-state batteries (SSBs) are considered to be one of the most promising candidates for next-generation energy storage systems due to the high safety, high energy density and wide operating temperature range of solid-state electrolytes (SSEs) they use. Unfortunately, the practical application of SSEs has rarely been successful, which is largely attributed to the low chemical stability and ionic conductivity, ineluctable solid-solid interface issues including limited ion transport channels, high energy barriers, and poor interface contact. A comprehensive understanding of ion transport mechanisms of various SSEs, interactions between fillers and polymer matrixes and the role of the interface in SSBs are indispensable for rational design and performance optimization of novel electrolytes. The categories, research advances and ion transport mechanism of inorganic glass/ceramic electrolytes, polymer-based electrolytes and corresponding composite electrolytes are detailly summarized and discussed. Moreover, interface contact and compatibility between electrolyte and cathode/anode are also briefly discussed. Furthermore, the electrochemical characterization methods of SSEs used in different types of SSBs are also introduced. On this basis, the principles and prospects of novel SSEs and interface design are curtly proposed according to the development requirements of SSBs. Moreover, the advanced characterizations for real-time monitoring of interface changes are also brought forward to promote the development of SSBs.

Multifunctional visualized electronic skin based on a solvatochromic poly (ionic liquid) ionogel

The biological skins exhibit various fascinating visual functions, such as turning red in response to strain, whitening upon hydrogen peroxide stimulation, and changing color in accordance with the environment (octopus). Inspired by these phenomena, two kinds of multifunctional visualized electronic skin (e-skin) were designed and fabricated based on a novel poly (ionic liquid) ionogel. Herein, we reported a transparent and conductive poly (ionic liquid) ionogel (P(AAm-IL)) by photopolymerizing acrylamide (AAm) with 1-vinyl-3-butylimidazolium tetrafluoroborate (ionic liquid, IL) in ethylene glycol (EG). Interestingly, P(AAm-IL) displays a solvatochromic phenomenon, and typical hydrogen-bonding acceptor solvents like acetone, methanol, and nitromethane induce a whitening effect in it. Based on this ionogel, we fabricated multifunctional strain sensors integrated with the visualized chemical sensing ability. The discoloration mechanism of the chemical sensing was detailed studied. Furthermore, by combining the P(AAm-IL) ionogel with Lithium trifluoroethane sulfonate (LiTf), the blend P(AAm-IL)-Li ionogel exhibits enhanced stretchability (>4300 %), higher conductivity (1.44 × 10−2 S·m−1), good transparency (>80 %) as well as wide operating temperature range (−20 to 80 °C). A sandwich-structured e-skin (Polypyrrole/PAAm-IL-Li/CsPbBr3-TPU) exhibiting both electro-optical dual response to strain was successfully fabricated. The luminescent e-skin not only exhibits highly sensitive electrical responses but also demonstrates visible fluorescence changes in response to external strain variations. These multifunctional visualized e-skins demonstrate great potential for applications in chemical environmental monitoring robotics, wearable electronic devices, and human–computer interaction.

A multi-time-scale framework for state of energy and maximum available energy of lithium-ion battery under a wide operating temperature range

Lithium-ion batteries are one of the best choices as energy storage devices for self-powered nodes in wireless sensor networks (WSN) due to their advantages of no memory effect, high energy density, long cycle life, and being pollution-free after being discarded, ensuring that the sensor nodes maintain high power operation for a long time. An improved co-estimation framework for SOE and maximum available energy has been established, considering the problem of maximum available energy decay caused by temperature and battery charge-discharge rate, which can update the maximum available energy in real-time and reduce SOE errors caused by fixed energy values. A multi-timescale SOE and maximum available energy co-estimation framework is proposed to address the asynchronous and coupled characteristics of maximum available energy and SOE estimation, effectively reducing the algorithm's computational complexity. The proposed algorithm is experimentally verified according to the designed dynamic stress test conditions of lithium-ion batteries in WSN nodes. The experimental results show that smaller time scales can provide more accurate and reliable maximum available energy correction and higher SOE estimation accuracy, but the computational time cost is higher than that of larger time scales. To balance SOE estimation accuracy and algorithm computational complexity, the appropriate time scale should be selected based on the SOE estimation accuracy and time cost in practical battery management system working conditions.

Investigating the physical properties of lead-free halide double perovskites Cs2AgXBr6 (X = P, As, Sb) for photovoltaic and thermoelectric devices using the density functional theory

Lead-free halide double perovskites are promising materials for photovoltaic and thermoelectric applications due to their desirable functional features. In the present study, Wien2k ab-initio code based on the density functional theory (DFT) was employed to Cs2AgXBr6 (X = P, As, and Sb) to investigate their structural, electronic, mechanical, optical, and thermoelectric properties. The obtained results show that all compounds are mechanically stable. Both Cs2AgPBr6 and Cs2AgSbBr6 are ductile materials whereas Cs2AgAsBr6 is brittle. On the other hand, the atomic bonds of Cs2AgAsBr6 are stronger than those of the other two compounds, and its lattice structure is more rigid. Based on the hybrid functional (YS-PBE0) potential, the bandgap of Cs2AgXBr6 (X = P, As and Sb) was identified as indirect and have the values of 1.113, 1.517, and 1.672 eV, respectively. All compounds have high optical conductivity in the visible region and show the greatest absorption in the UV–visible region. Additionally, the positive values of Seebeck and Hall coefficients over the entire temperature range indicate the presence of hole-type charge carriers in these materials. The calculated thermoelectric Figure of Merit shows a broad plateau over the investigated temperature range which ensures stable efficiency over a wide operating temperature range. The present study demonstrates the potential of the investigated compounds to be utilized in photovoltaic and thermoelectric applications.