Wide Operating Temperature Research Articles

Rare-earth element doped barium titanate-based ceramics exhibiting ultra-wide temperature span electrocaloric effect

Electrocaloric effect (ECE) refrigeration stands out as a promising alternative to conventional compression refrigeration owing to its potential for miniaturization, high energy conversion efficiency, cost-effectiveness, and environmental friendliness. However, the practical applications of ECE refrigeration in lead-free ceramics face limitations due to the challenge of achieving a substantial adiabatic temperature change (ΔT) and a wide operating temperature span (Tspan). In this study, we tackle this challenge by introducing rare-earth Sm3+ ions into Ba(Ti0·90Sn0.10)O3 (BTSn) ceramics to enhance their ECE stability. We comprehensively investigate the structural, dielectric, and ECE properties of (Ba1−3x/2Smx) (Ti0·9Sn0.1)O3 (BSmTSn, x = 0−0.03) ceramics. Our findings reveal that the incorporation of Sm3+ ions leads to a reduction in the temperature at which the permittivity reaches its maximum, accompanied by an increased dispersion compared to undoped BTSn ceramics. Particularly noteworthy is the achievement of a ΔT of 0.9 K with a Tspan of 55.5 °C in the x = 0.005 composition. Furthermore, increasing x to 0.01 enables the realization of a wide Tspan of 70 °C, starting from 30 °C. These significant enhancements in the Tspan across all BSmTSn ceramics, facilitated by the introduction of Sm3+ ions, present a promising strategy for optimizing the ECE performance of BaTiO3-based ceramics.

РОЛЬ ТЕХНОЛОГИЧЕСКИХ ФАКТОРОВ В ФОРМИРОВАНИИ СТРУКТУРЫ ОТКРЫТОПОРИСТЫХ ВСПЕНЕННЫХ МАТЕРИАЛОВ НА ОСНОВЕ ЭТИЛЕН-ПРОПИЛЕН-ДИЕНОВЫХ СОПОЛИМЕРОВ ПУТЕМ КОМПРЕССИОННОГО ФОРМОВАНИЯ

Ethylene-propylene copolymers (EPDM) are known for a wide range of useful properties. EPDM-based rubbers have weather resistance, resistance to aggressive environments and wide operating temperatures. EPDM-based blends allow to create composite materials such as open-cell polymer foam. Due to their unique composition, open-cell elastomeric foam based on EPDM can have different structures, densities and properties. This paper presents a study of the possibilities of technologies of first-stage and second-stage foaming in vulcanization presses in order to regulate the pore structure of open-cell material based on ethylene-propylene-diene copolymer.

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.

A new type of lanthanide–sodium metalloring organic framework featuring high proton conduction in a wide temperature range and detection of Fe3+ ions

The unprecedented octanuclear lanthanide–sodium metalloring cluster organic framework exhibits proton conductivity in a wide operating temperature range and sensitive sensing of iron ions.

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.

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.

Thermal Stability and Performance Evaluation of Hitec Molten Salt for High-Temperature Energy Storage Applications

The quest for advanced materials in thermal energy storage (TES) has become paramount in a world grappling with pressing demands for sustainable and reliable energy solutions. Among these materials, molten salts have emerged as up-and-coming contenders, owing to their exceptional thermal properties and wide operational temperature ranges. HITEC, a eutectic blend of sodium nitrate, sodium nitrite, and potassium nitrate, distinguishes itself as a superior choice due to its unique amalgamation of favorable thermal characteristics. This comprehensive review delves into the thermal properties of HITEC molten salt and its manifold applications in thermal energy storage, illuminating its potential as a pivotal element in addressing contemporary global challenges. The review examines HITEC's specific heat capacity, thermal conductivity, and thermal stability, presenting critical insights into its efficacy as a TES medium. Such comprehension fosters the advancement of Sustainable Development Goal 7. The article explores strides made in HITEC-based TES systems, underscoring inventive engineering approaches and burgeoning technologies that bolster progress towards Sustainable Development Goal 9. Furthermore, the article discusses challenges associated with HITEC molten salts, such as corrosion and material compatibility issues, and investigates ongoing research efforts to overcome these limitations. A comparative evaluation of HITEC with other molten salt mixtures elucidates its competitive advantages. This review consolidates knowledge about HITEC molten salt for thermal energy storage applications, providing valuable perspectives for researchers, engineers, and policymakers dedicated to advancing sustainable energy technologies. The review underscores the pivotal role of HITEC molten salt in advancing thermal energy storage technologies, directly influencing the achievement of several SDGs.

Enabling wide temperature battery operation with hybrid lithium electrolytes.

We demonstrate that an ionic liquid 1-ethyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide combined with propylene carbonate and lithium bis(trifluoromethanesulfonyl)imide yields a hybrid electrolyte that enables a wide operational temperature window (-20 °C to 60 °C). When integrated into a lithium titanate‖lithium cobalt oxide full-cell configuration, high-rate capability is achieved at -20 °C with >40% retention at a C/2 cycling rate, and negligible capacity fade is observed during rate capability tests and long-term cycling at 60 °C.

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.

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.

Schiff base and coordinate bonds cross-linked chitosan-based eutectogels with ultrafast self-healing, self-adhesive, and anti-freezing capabilities for motion detection

Ion conductors offer great potential for diverse electric applications. However, most of the ion conductors were fabricated from non − degradable petroleum−based polymers with non or low biodegradability, which inevitably leads to resource depletion and waste accumulation. Fabricating ion conductors based on renewable, and sustainable materials is highly desirable and valuable. Herein, a series of eutectogels were designed through dual−dynamic−bond cross−linking among ferric iron (Fe3+), protocatechualdehyde (PA), and chitosan (CS) in 1 − allyl−3 − methylimidazole chloride ionic liquid/urea (AmimCl/urea) eutectic−based ionic liquid. Due to the presence of AmimCl/urea eutectic−based ionic liquid, the obtained CS − PA@Fe eutectogels showed excellent ionic conductivity, superior anti−freezing properties that could maintain flexibility and high electrical properties at −20 °C. Dual−dynamic−bond cross−linking of catechol−Fe coordinate and dynamic Schiff base bonds equip CS − PA@Fe eutectogels with excellent injectable, and self−healing abilities. Additionally, due to the presence of phenolic hydroxyl groups of PA, the obtained CS − PA@Fe eutectogels present good adhesiveness. Based on the CS − PA@Fe eutectogels, multifunctional flexible strain sensors with high sensitivity, stability, as well as rapid response speed at wide operating temperature ranges were successfully fabricated. Thus, this study offers a promising strategy for fabricating naturally occurring biopolymers based eutectogels, which show great potential as high−performance flexible strain sensors for next−generation wearable electronic devices.

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.

Synergistic effect of platinum single atoms and nanoclusters for preferential oxidation of carbon monoxide in hydrogen-rich stream

Despite the maximum atom-utilization efficiency and remarkable activity of single-atom catalysts, further improvement of catalytic activity can be obtained by the synergistic effect of single atoms and nanoclusters in some catalytic systems. Herein, CeFeOx-supported Pt single atoms coupling with subnanometric clusters (Pt1-Ptn) structures are developed via a facile strategy. They are applied as the highly efficient catalysts for the preferential oxidation of CO in H2-rich stream (CO-PROX), which achieve complete elimination of CO at low temperature of 50 °C, with a wide operating temperature window and extraordinary stability for over 500 h without noticeable deactivation. The exceptional performance is attributed to the synergistic effect of distinctive Pt1-Ptn structures, which couple the benefits of Pt single atoms and subnanometric clusters in a remarkable way. The disadvantages of single Pt species catalysts, such as sensibility to strong adsorption of CO or reduced lattice oxygen reactivity due to excessive coordination, can be well mitigated. The results of detailed characterizations and density functional theory calculations confirm that the unique structures possess moderate adsorption strength for CO and create abundant active interfacial oxygen species, because of the absence of bulk metallic Pt0 and appropriate coordination to lattice oxygen, which synergistically facilitate the catalytic performance.

Electro‐Driven, Predefined Carbon Nanotube‐Based Phase Change Composite as a Lifting‐Jack

AbstractShape change materials or actuators that are capable of shrinking, bending or rotation under external stimuli (especially, by electricity), have attracted tremendous research interest in past years. Controlled shape change with large output capacity under low excitation voltage remains a challenging task in this field. Here, an electro‐driven carbon nanotube sponge/paraffin wax bulk composite (CS@PW) that can perform various shape change functions such as, in particular, jacking and lifting heavy objects (up to 668.3 times of composite weight) under lower voltages (4–8 V) with fast response and high reversibility is presented. This unique and superior jacking performance is attributed to the predefined original CS shape, the deformability and resilience derived from 3D porous CS@PW, and efficient Joule heat transfer from conductive CS to the coaxially wrapped PW layer; the latter, by reversible phase change solidification/melting, can fix or release carbon nanotube network to enable controlled fixation/motion. Additional advantages include hydrophobicity, anti‐leakage, wide operating temperature, and diverse reversible shape change modes based on CS@PW and commercial polyethylene tapes, are also demonstrated. The designed electro‐driven nanocomposites, combining resilient carbon nanotube networks with low‐cost organic phase‐change material, have wide applications in areas such as robust artificial muscles, intelligent morphing, and energy management.

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.