Optical Energy Storage Research Articles

Highly Nonlinear Light-Nucleus Interaction.

The interaction between light and atomic nuclei is typically weak and confined within the linear and perturbative regime, which limits the achievable nuclear excitation probability and impedes potential applications such as nuclear optical clocks, nuclear lasers, and nuclear energy storage. In this Letter we show that the interaction between hydrogenlike thorium-229 ions (^{229}Th^{89+}) and contemporary intense lasers propels light-nucleus interaction into a highly nonlinear and nonperturbative regime. This interaction unlocks remarkably efficient nuclear excitation: over 10% of the ^{229}Th nuclei can be excited to the isomeric state by a single femtosecond laser pulse. Moreover, the laser-driven ^{229}Th^{89+} ions radiate multiple wavelengths of light that are high-order harmonics of the laser frequency, akin to the high harmonic generation process from laser-driven atoms but with distinct characteristics. These results pioneer a new frontier for exploring light-matter interaction, furnish a powerful method for efficient control over atomic nuclei, and pave a new way of nuclear coherent light emission.

A molecular-chemistry-manipulation strategy toward functional lignin-based porous carbon nanospheres with tunable-pore structure

Porous carbon nanospheres derived from biomass materials have inspired numerous interests in various areas. Nevertheless, their fabrications mainly depend on template-assisted or chemical activation routes. Here, a molecular-chemistry-manipulation strategy was proposed innovatively by taking advantage of the heterogeneous self-condensation characters of lignin molecules under thermal stimulation, opening a practical and versatile synthetic platform for the construction of lignin-based hierarchical porous carbon nanospheres (LHPCS). We can manipulate the condensed kinetics by tuning the environmental variables and forming designated nanospheres with inhomogeneous molecular chemistry. This intraparticle difference could provide a possibility to tune its refined structure for synthesizing hierarchical porous carbon nanospheres. Such LHPCS behaved the specific surface area of 962 m2 g−1 and pore volume of 0.76 cm3 g−1, as well as regulable pore ratios (15.5–22.9 % of macropore, 12.7–37 % for mesopore and 45–68.9 % for micropore). Besides, the monodisperse spherical morphology with hierarchical interleaved channels affords them excellent performance in optical management and energy storage, including pore-determined photothermal properties, extremely low reflectance of ca. 1.9 %, stable multi-angles specular reflectance, and anti-self-discharge induced by charge rearrangement. Our proposed molecular chemistry strategy provides an alternative pathway for constructing gradient and adjustable pore structures.

Silver nanowires/WO3 quantum dots electrode with enhanced vertical electric field gradient for Al3+/Li+ dual-functional electrochromic supercapacitor

Dual-functional electrochromic supercapacitors (DECSs), which demonstrate the substantial potential for reversible changes in optical properties and energy storage capabilities, hold considerable promise for a wide range of applications in areas such as smart windows, displays, and wearable electronics. Nevertheless, challenges still exist in effectively optimizing their capacitance, ensuring cycling stability, and achieving cost-effective fabrication. Herein, this study explores an approach by integrating Al3+ and Li+ ions as hybrid electrolyte to enhance electrochemical activity. Utilizing WO3 quantum dots (WQDs) embedded within Ag nanowires (Ag NWs) grids offers a promising strategy to augment the vertical electric field gradient and prevent the self-agglomeration of WQDs. In addition, the integration of hybrid electrolyte comprising Al3+ and Li+ ions not only enhance electrochemical activity but also serves to mitigate the high-cost lithium sources. The resulting Ag NWs/WQDs electrode exhibits an impressive specific capacitance of 681.6 F g−1 at 0.25 mA cm−2 in Al3+/Li+ hybrid electrolyte, a notable 5-fold increase compared to the pristine WQDs electrode in Li+ electrolyte (139.3 F g−1). Simultaneously, this dual-function electrode demonstrates a large optical modulation (81.8 % at 700 nm), a fast switching-speed (tbleaching=7 s, tcoloring=5 s), and a long cycling life (maintaining 84.6 % of its original capacitance after 5000 cycles). Noteworthy insights from COMSOL simulations highlight the Ag NWs grid's "conductive bridge" function, which shows a positive attribution in optimizing the vertical electric field gradient. As a demonstration of proof-of-concept, a large-size flexible dual-functional electrochromic supercapacitor (DECS, 15 cm×10 cm) confirms energy-saving and storage dual-functionality device. Typically, the DECS-equipped inner room experiences a temperature 10°C lower than that of a room with a blank PET within 10 min, indicating the significant irradiation shielding. In addition, this device exhibits a remarkable specific capacitance of 9.25 mF cm−2 at 5 mV s−1, accompanied by an exceptional stability under simulated solar irradiation. The innovation of 0D/1D hierarchical structure of the electrodes together with the hybrid electrolyte not only reduce costs but also enhance the capacitance and cycle stability of DECSs, offering new insights for the development of next-generation flexible electronic wearables.

Effect of SiO2-doped nanoparticle/electrostatic spinning system on the electro-optical properties of polymer dispersed liquid crystals for smart windows

ABSTRACT Polymer Dispersed Liquid Crystal (PDLC) films are attracting increasing attention as versatile and innovative material for use in electrical switching and flexible devices. This paper investigates the effect of a Poly(methyl methacrylate (PMMA) nanospun membrane system doped with SiO2 nanoparticles on the electro-optical properties and transmittance/voltage slopes of thiol- and acrylate-based PDLC films. Experimental samples were prepared for testing by adding mixtures of liquid crystals and crosslinkers in different proportions to liquid crystal cassettes doped with PMMA/SiO2 nanospun membranes. The size of the polymer mesh was found to influence all parameters of PDLC. The phase separation process, which determines the morphology and electro-optical properties of PDLC films, is directly affected by the doping of different components of PMMA/SiO2. The doping of the PMMA/SiO2 system resulted in improved optoelectronic properties of PDLC films, significantly enhanced weathering resistance, and increased the degree of intelligent regulation of the transmittance of PDLC films. Thus, by developing PDLC-doped reticulated nanofibre films with faster response times and better electro-optical properties, the potential for technological applications of PDLC-based devices in optical windows, displays, energy storage and flexible devices can be significantly enhanced.

Tuning the optical, and dielectric properties of PVC/PEO/NiMoO4/MWCNTs/x wt %PANI blended polymers for optoelectronic applications

Nanoparticles of nickel molybdate (NiMoO4) have attracted significant interest for their application as electrode materials. Here, new hybrid blended polymers, poly (vinyl chloride)/polyethylene oxide/nickel molybdate/multi-walled carbon nanotubes/polyaniline (PVC/PEO/NiMoO4/MWCNTs/x wt %PANI) were prepared. Several techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), diffused reflectance, fluorescence and LCR meter were used to investigate the impact of the different fillers on the structure, electrical and optical features of the PVC/PEO blend. The structures of NiMoO4 and different blends were explored using XRD technique. The linear and nonlinear optical properties and the emitted colors of host blend are found to be affected by NiMoO4, MWCNTs and different amounts of PANI fillers. The T values of PVC/PEO were reduced as it loaded with NiMoO4/MWCNTs/x wt %PANI and it reached its minimum value (21–37% in the visible range) in NiMoO4/MWCNTs/x 0.4 %PANI blend. The minimum direct and indirect optical band gap values (4.09, 4.9) eV and (1.92, 3.47, 3.94) eV, respectively, were obtained as the amount of PANI became 0.4 wt % in the doped blend. The doped PVC/PEO blend with NiMoO4 has the highest refractive index value (2.11) at 600 nm. The highest nonlinear optical parameters were acquired exclusively in the visible spectrum when PVC/PEO was doped with NiMoO4.The maximum energy density value (6.03 × 10−3 J/m3) was obtained when the host blend loaded with NiMoO4/MWCNTs. Thus, PVC/PEO/NiMoO4/MWCNTs/x wt %PANI blends are recognized as a good prospect for UV blocking, solar cell, optoelectronic, nonlinear optical devices and energy storage innovation.

Photonic Neural Networks Based on Integrated Silicon Microresonators

Recent progress in artificial intelligence (AI) has boosted the computational possibilities in fields in which standard computers are not able to perform adequately. The AI paradigm is to emulate human intelligence and therefore breaks the familiar architecture on which digital computers are based. In particular, neuromorphic computing, artificial neural networks (ANNs), and deep learning models mimic how the brain computes. There are many applications for large networks of interconnected neurons whose synapses are individually strengthened or weakened during the learning phase. In this respect, photonics is a suitable platform for implementing ANN hardware owing to its speed, low power dissipation, and multi-wavelength opportunities. One photonic device that could serve as an optical neuron is the optical microring resonator. Indeed, microring resonators exhibit a nonlinear response and the capability for optical energy storage, which can be used to implement fading memory. In addition, their characteristic resonant behavior makes them extremely sensitive to input wavelengths, which promotes wavelength division multiplexing (WDM) applications and enables their use as WDM-based synapses (weight banks) in the linear regime. Remarkably, using silicon photonics, photonic integrated circuits can be fabricated in volume and with integrated electronics onboard. For these reasons, here, we describe the physics of silicon microring resonators and arrays of microring resonators for application in neuromorphic computing. We describe different types of ANNs, from feedforward networks to photonic extreme learning machines, and reservoir computing. In addition, we discuss hybrid systems in which silicon microresonators are coupled with other active materials. This review introduces the basics and discusses the most recent developments in the field.

Singular optical propagation properties of two types of one-dimensional anti- PT -symmetric periodic ring optical waveguide networks

Two types of one-dimensional (1D) anti- PT -symmetric periodic ring optical waveguide networks, consisting of gain and loss materials, are constructed. The singular optical propagation properties of these networks are investigated. The results show that the system composed of gain materials exhibits characteristics of ultra-strong transmission and bidirectional reflection. Conversely, the system composed of loss materials demonstrates equal transmittance and reflectance at some frequencies. In both the systems, a new type of total reflection phenomenon is observed. When the imaginary part of the refractive indices of waveguide segments is smaller than 10−5, the system shows bidirectional transparency with the transmittance tending to be 1 and reflectivity to be smaller than 10−8 at some bands. When the refractive indices of the waveguide segments are real, the system will be bidirectional transparent at the full band. These findings may deepen the understanding of anti- PT -symmetric optical systems and optical waveguide networks, and possess potential applications in efficient optical energy storage, ultra-sensitive optical filters, ultra-sensitive all-optical switches, integrated optical chips, stealth physics, and so on.

Economic optimization scheduling of multi‐microgrid based on improved genetic algorithm

AbstractIn order to solve the collaborative optimization scheduling of multi‐microgrid under the high penetration rate of new energy, this paper considered the energy interaction between micro‐grids in multi‐microgrid and the relationship between new energy consumption and electricity cost, constructed a collaborative scheduling model considering both micro‐grid load and main grid wind and optical energy storage, proposed objective function based on economic cost, and improved Genetic Algorithm (GA). The elite thought and catastrophe thought are used to optimize the selection operation, and the particle swarm optimization algorithm is used to optimize the mutation operation. Furthermore, three scenarios were selected to verify the effectiveness of the proposed model and the improved GA. The results show that the proposed model can ensure the stable operation of the multi‐microgrid system with a high proportion of new energy access and reduce the operation cost. In addition. the improved algorithm solves the problems of easy to fall into local optimum and slow iteration speed, and has better performance in solving the model.

A new photoelectric niobate glass ceramic material: Up-conversion optical thermometry and dielectric energy storage

To develop new inorganic multifunctional materials, a series of Yb3+/Er3+ doped precursor glasses (PGs) were fabricated through melt quenching technique, and a novel niobate transparent photoelectric glass ceramic (GC) was gained via controlled crystallization of PG. Compared with PG, the up-conversion (UC) luminescence performance is significantly increased in GC. Utilizing the temperature dependence of the emission intensity of Er3+ ions, the dual-mode optical temperature measurement is realized through fluorescence intensity ratio (FIR) methods. The ultimate absolute sensitivity (Sa-max) and relative sensitivity (Sr-max) based on the thermal/non-thermal coupling energy levels (TCELs/NTCELs) are 0.68 %K−1 and 0.85% K−1, respectively. Moreover, the single-layer capacitor made of GC can release energy density of 0.83 J/cm3 (@600 kV/cm) and power density of 210 MW/cm3. This work indicates that niobate transparent glass ceramics are expected to be applied in the optical thermometry and pulse energy storage field.

The development and applications of nanoporous gallium nitride in optoelectronics: a review

The development of nanoporous gallium nitride (NP-GaN) has widened the material properties and applications in third-generation semiconductor areas. NP-GaN has been used in laser emitters, light-emitting diodes, optical sensors, and optical energy storage devices. In this paper, we reviewed the most recent progress in the NP-GaN field by electrochemical etching. The etched GaN has many superior properties compared with original GaN templates, such as stronger photoluminescence intensity, thermal conductivity, piezo-electricity, more accessible area, stress relief, and refractive index. These advantages will make GaN more widely used in the field of optics and optoelectronics. Pore formation can be controlled by adjusting the applied potential and etching time. The NP-GaN makes the material of GaN have broader application prospects. We introduced in detail the application prospects of different GaN based processes and subsequent application methods in optoelectronics, sensors, and materials themselves. This review will help to improve further development of NP-GaN applications.

Effects of Gamma Irradiation on Optical Properties of Poly(ethylene oxide) Thin Films Doped with Potassium Iodide

In this study, the effect of gamma irradiation on the optical properties of thin films of polymer electrolytes was investigated. The thin films were composed of poly(ethylene oxide) (PEO) doped with different concentrations of potassium iodide (KI) salt. The optical absorption spectrum of each film was measured using a UV–Vis spectrophotometer over a range of 300 to 800 nm. The PEO thin-film samples were subjected to gamma irradiation at two different doses of 100 and 200 Gy generated by a Co-60 source. It was found that the optical properties of the thin films were significantly influenced by the KI dopant concentration and gamma irradiation. Increasing both the KI concentration and the gamma irradiation dose resulted in a reduction in the energy gap and an increase in the absorption coefficient, extinction coefficient, refractive index, and dielectric constant of the PEO electrolyte. These findings have potential applications in the optimization of polymers for use in optical devices and energy storage systems.

Shape-stabilized 1-hexadecanol/g-C3N4/Cu composite phase change material with high thermal conductivity for efficient photo-thermal conversion

Phase change materials (PCM) have received much attention for thermal energy storage and release in the form of latent heat. 1-hexadecanol (HD), as a representative of organic phase change materials, has the advantages of high thermal storage density, almost constant operating temperature and stable thermochemical properties, which shows outstanding potential in the field of phase change energy storage. Nevertheless, single HD as thermal storage material inevitably faces challenges in terms of liquid phase leakage, low thermal conductivity, and poor photo-thermal conversion. To further improve the practical application of HD, we demonstrate a convenient encapsulation and modification strategy of composite phase change materials (CPCMs) with low liquid leakage and high thermal conductivity. Hence, a novel shape-stabilized Cu-doped HD/ graphitic carbon nitride (g-C3N4) CPCM was developed for efficient photo-thermal storage. By the melt blending method, HD is infiltrated into tightly stacked and aligned nano-porous g-C3N4, and the carbon-based lattice inlay achieves the encapsulation of HD to solve the leakage problem during the solid–liquid phase transition. Then, metallic Cu powder is introduced to further strengthen the thermal conductivity of the materials. With this encapsulation and modification strategy, the obtained 5 wt% Cu-doped HD/g-C3N4 composites (CPCM3) exhibits superior performance in both thermal and optical energy storage. This composite has appropriate phase change temperature and extremely high heat storage density, with melting temperature and latent heat of 48.88 °C and 249.63 J/g. The corresponding solidification temperature and latent heat is 48.52 °C and 242.22 J/g, respectively. Its thermal conductivity is enhanced to 0.5307 W/m·K, which is 59.8% higher than pure HD. The photo-thermal conversion efficiency is up to 81.6% for rapid solar energy harvesting and delivery. In particular, after 100 times thermal cycling tests and thermogravimetric analysis, this special CPCM can maintain good thermal reliability and thermal stability. In conclusion, the composite phase change materials obtained by the synergistic modification strategy of nano-porous g-C3N4 and metallic Cu significantly improved the thermochemical properties of HD. This work provides a practical and efficient synthetic strategy for the preparation of CPCMs, which is expected to present a promising future in the field of solar conversion and storage.

Modulation of electro-optical properties of polymer-dispersed liquid crystals by multi-walled carbon nanotube/polymer nanocomposite fibres

ABSTRACT In this article, polymer-dispersed liquid crystal (PDLC) films were prepared from a mixture of prepolymer, liquid crystal and reticular nanofibre films containing multi-walled carbon nanotubes (MWCNT) by the polymerisation-induced phase separation (PIPS) method. By comparing the microstructure and electro-optical profiles of different contents of liquid crystals as well as monomer types, it was demonstrated that the pore size pairs of the polymer network can modify the electro-optical properties of PDLC. Different types of loaded multi-walled carbon nanotube reticular nanofibre films were introduced into the liquid crystal mixture specimens and the altered polymer network and electro-optical properties of these specimens were analysed using SEM, POM, TEM, and electro-optical curves. It was found that the electro-optical properties of PDLC were greatly improved and the resistance to ageing was also greatly enhanced by mesh nanofibre films doped with a certain amount of multi-walled carbon nanotubes. Therefore, the development of PDLC doped with loaded MWCNT reticular nanofibre films with faster response times and better electro-optical properties will greatly improve the promising technological applications of PDLC-based devices for optical windows, displays, energy storage and flexible devices.

Multi-ratio optical thermometry and energy storage characteristics of Yb3+/Er3+/Tm3+ doped BaNb2O6 transparent glass-ceramics

• RE-doped BaNb 2 O 6 transparent glass ceramics (GCs) were fabricated firstly. • Realizing three-mode Up-conversion optical thermometry in the GCs. • The maximum S r-max and S a-max can reach 2.30% K –1 and 6.71‰ K –1 . • Achieving high W d of 0.99 J cm –3 and high P d of 225.3 MW cm –3 . • Multifunctional GCs can be used in optical sensing and energy storage fields. In order to meet the needs of new materials gradually developing towards miniaturization, integration, and light weight, multifunctional BaNb 2 O 6 : Yb 3+ /Er 3+ /Tm 3+ transparent glass-ceramics were successfully prepared by melt quenching and controllable crystallization. Its structure, luminescence, and energy transmission were studied. Using the opposite temperature dependence of the Tm 3+ emission band and the corresponding large energy level gap, a maximum relative sensitivity of 2.3% K –1 based on thermal coupling levels (TCLs) is obtained in a wide temperature range (298–673 K). The multi-ratio optical thermometry based on TCLs and non-TCLs is successfully realized by using the different emission bands of double emission centers, which makes it possible for self-reference optical temperature measurement modes. In addition, the transparent glass-ceramic exhibits excellent electrical properties under 700 kV cm –1 electric field: high discharge energy density ( W d = 0.99 J cm –3 ), huge instantaneous power density (225.3 MW cm –3 ), and ultra-fast discharge rate ( T 0.9 ≤ 15.8 ns). The prepared glass-ceramic is expected to be a new type of lead-free multifunctional photoelectric material for temperature sensors and transparent electronic devices.

Superior Energy Storage Properties and Optical Transparency in K0.5 Na0.5 NbO3 -Based Dielectric Ceramics via Multiple Synergistic Strategies.

Eco-friendly transparent dielectric ceramics with superior energy storage properties are highly desirable in various transparent energy-storage electronic devices, ranging from advanced transparent pulse capacitors to electro-optical multifunctional devices. However, the collaborative improvement of energy storage properties and optical transparency in KNN-based ceramics still remains challenging. To address this issue, multiple synergistic strategies are proposed, such as refining the grain size, introducing polar nanoregions, and inducing a high-symmetry phase structure. Accordingly, outstanding energy storage density (Wtotal ≈7.5 J cm-3 , Wrec ≈5.3 J cm-3 ) and optical transmittance (≈76% at 1600nm, ≈62% at 780nm) are simultaneously realized in the 0.94(K0.5 Na0.5 )NbO3 -0.06Sr0.7 La0.2 ZrO3 ceramic, together with satisfactory charge-discharge performances (discharge energy density: ≈2.7 J cm-3 , power density: ≈243 MW cm-3 , discharge rate: ≈76ns), surpassing previously reported KNN-based transparent ceramics. Piezoresponse force microscopy and transmission electron microscopy revealed that this excellent performance can be attributed to the nanoscale domain and submicron-scale grain size. The significant improvement in the optical transparency and energy storage properties of the materials resulted in the widening of the application prospects of the materials.

High-performance electrochromic supercapacitor based on an electroactive polyimide containing pentaaniline

Attributed to their obvious color transition, good electrochemical reversibility, and high theoretical capacitance, polyaniline-based electrochromic supercapacitors have recently garnered significant attention in wearable devices, intelligent power supplies, and smart windows. However, its limited processability as well as poor electrochemical endurability have severely hampered polyaniline's practical application in this regard. Herein, a new electroactive polyimide containing pentaaniline in the main chain has been facilely designed and synthesized using oxidative coupling polymerization followed by thermal imidization. Rational matched with vanadium pentoxide ion-storage counter electrode, a quasi-solid-state electrochromic supercapacitor device (QSES) is manufactured with desirable simultaneous optical change and energy storage performance of high optical contrast of 68%, fast switching speed of 1.29/1.58 s, good open circuit memory (1.28% decay after power off for 3600 s), wide voltage window of 2 V, large capacitance of 41.53 mF/cm2, and outstanding cycling durability (85% capacitance and 96% optical modulation retention after 10000 cycles at 0.2 mA/cm2). This study provides a feasible approach of molecular designing for achieving processable electroactive polymer and shows the promising potential of the resultant electrochromic supercapacitor in smart power supply devices with energy level indication functionality.

Tailoring Cooperative Emission in Molecules: Superradiance and Subradiance from First-Principles Simulations

Cooperative optical effects provide a pathway to both the amplification (superradiance) and the suppression (subradiance) of photon emission from electronically excited states. These captivating phenomena offer a rich variety of possibilities for photonic technologies aimed at electromagnetic energy manipulation, including lasers and high-speed emitting devices in the case of superradiance or optical energy storage in that of subradiance. The employment of molecules as the building pieces in these developments requires a precise understanding of the roles of separation, orientation, spatial distribution, and applied fields, which remains challenging for theory and experiments. These questions are addressed here through ab initio quantum dynamics simulations of collective emission on the basis of a novel semiclassical formalism and time-dependent density functional theory. By establishing the configurations leading to decoherence and how the fine-tuning of a pulse can accumulate or release optical energy in H2 arrays, this report provides fundamental insight toward the design of real superradiant and subradiant devices.

The role of nanomesh fibres loaded with BaTiO3 nanoparticles on the electro-optical performance of PDLC devices

In this paper, polymer-dispersed liquid crystal (PDLC) films were prepared from a blend of prepolymer, liquid crystal and BaTiO3 (BTO) nanoparticle-laden nanofibres films by a polymerisation-induced phase separation (PIPS) method. By contrasting the microstructure and electro-optical curves of various proportions of monomer types, it was demonstrated that the hole size of the polymer network had a significant influence on the electro-optical nature of the PDLC films. nanofibres films loaded with different BTO nanoparticle contents were introduced into the liquid crystal mixture specimens, and the alterations in the polymer network, electro-optical nature of these specimens were analysed using SEM images, EDS and electro-optical curves. The electro-optical nature of the nanofibres films doped with PDLCs were found to be improved and the ageing resistance was greatly enhanced. Therefore, the development of PDLC films with faster response times and better electro-optical nature of reticular nanofibres films doped with PDLCs will significantly improve the promising technological applications of PDLC-based equipment for optical windows, displays, energy storage and flexible devices.

Extraordinarily Stable Aqueous Electrochromic Battery Based on Li4Ti5O12 and Hybrid Al3+/Zn2+ Electrolyte.

Aqueous electrochromic battery (ECB) is a multifunctional technology that shows great potential in various applications including energy-saving buildings and wearable batteries with visible energy levels. However, owing to the mismatch between traditional electrochromic materials and the electrolyte, aqueous ECBs generally exhibit poor cycling stability which bottlenecks their practical commercialization. Herein, we present an ultrastable electrochromic system composed of lithium titanate (Li4Ti5O12, LTO) electrode and Al3+/Zn2+ hybrid electrolyte. The fully compatible system exhibits excellent redox reaction reversibility, thus leading to extremely high cycling stabilities in optical contrast (12 500 cycles with unnoticeable degradation) and energy storage (4000 cycles with 82.6% retention of capacity), superior electrochromic performances including high optical contrast (∼74.73%) and fast responses (4.35 s/7.65 s for bleaching/coloring), as well as excellent discharge areal capacity of 151.94 mAh m-2. The extraordinary cycling stability can be attributed to the robust [TiO6] octahedral frameworks which remain chemically active even upon the gradual substitution of Li+ with Al3+ in LTO over multiple operation cycles. The high-performance electrochromic system demonstrated here not only makes the commercialization of low-cost, high-safety aqueous-based electrochromic devices possible but also provides potential design guidance for LTO-related materials used in aqueous-based energy storage devices.

Up-conversion luminescence, temperature sensitive and energy storage performance of lead-free transparent Yb3+/Er3+ co-doped Ba2NaNb5O15 glass-ceramics

In this work, a new type of Yb 3+ /Er 3+ co-doped lead-free glass-ceramics (GCs) containing Ba 2 NaNb 5 O 15 nanocrystals was synthesized via traditional melt-quenching and controlled crystallization. The research results illustrate that a transparency of GCs can reach 50% at wavelength of 600 nm and the up-conversion (UC) luminous performance of GCs has been improved obviously compared with precursor glass (PG). And the dual-mode temperature measurement was carried out by fluorescence intensity ratio technology. Using thermally/non-thermally coupled energy levels (TCELs/non-TCELs), the maximum absolute sensitivities of S a-max (TCELs) and S a-max (non-TCELs) are 0.65% K −1 and 0.68% K −1 , and the maximal relative sensitivities of S r-max (TCELs) and S r-max (non-TCELs) are 1.19% K −1 and 0.90% K −1 , respectively. Furthermore, the discharge energy density (W d ) of 1.53 J cm −3 and the instantaneous discharge power density of 370 MW cm −3 with ultra-fast discharge time of 7 ns are simultaneously achieved in the GCs. These findings reveal the potential applications of new lead-free transparent Yb 3+ /Er 3+ co-doped Ba 2 NaNb 5 O 15 GCs for optical temperature measurement and energy storage. • Multi-function RE-doped Ba 2 NaNb 5 O 15 transparent glass ceramics were first fabricated. • Realizing dual-mode Up-conversion optical thermometry in the glass ceramics. • The maximum S r-max and S a-max can reach 1.19% K −1 and 0.68% K −1 . • Achieving high W d of 1.53 J cm − 3 and high P d of 370 MW cm − 3 at 600 kV/cm.