Light Energy Storage Research Articles

Optically controlled phase change wood for energy storage and heat release

Molecular solar thermal (MOST) fuels efficiently store solar energy and release it as heat by photoisomerization-induced phase change. However, MOSTs still struggle to meet practical demands due to its slow cis-trans isomerization rate, solvent-assisted charging and low energy storage density. Herein, we develop an optically controlled phase change wood (OCPCW) through impregnating methoxyazobenzene (mAZO) into delignified basswood with light energy storage and thermal energy release. Wood, as supporting frame, accelerates the rate of cis-trans isomerization due to the dispersion of mAZO by wood pores. In addition, the per unit storage energy density of mAZO in OCPCW can reach 307.5 J·g−1, which is higher than that of pure mAZO (229 J·g−1), due to the hydrogen bonding between cellulose and mAZO. Under sunlight irradiation, the cis-OCPCM undergoes isomerization to trans-OCPCM, releasing heat and leading to a temperature increase approximately 2 °C higher than that of delignified basswood under identical conditions. Furthermore, color changing in response to phase change, the OCPCM could be designed for encrypted and decrypted information with dual imaging modes through the color change and exothermic behavior. This work paves the way for the development of phase change wood for efficient solar energy storage and release and application in encrypted information display.

Extension of the π-system of monoaryl-substituted norbornadienes with acetylene bridges: influence on the photochemical conversion and storage of light energy

Extension of the π-system of monoaryl-substituted norbornadienes with acetylene bridges: influence on the photochemical conversion and storage of light energy

Simultaneous enhancement of visible light absorption and energy storage performances of W5+ implanted WO3-x thin film electrodes

Herein, we report the implantation of oxygen vacancy dopants in electro-coated WO3 thin film electrodes for enhanced energy and environmental applications. The implantation method involved partial de-oxidation in sodium borohydride to introduce oxygen vacancies into the WO3 electrodes. The doped WO3-x demonstrated a significantly lowered average band energy of 2.11 eV, indicating its ability to absorb over 75 % of the visible light spectrum. Moreover, a thin film asymmetric supercapacitor assembled with WO3-x negatrode demonstrated an improved areal capacitance of 1.15 mFcm−2 and energy density of 0.33 μWhcm−2 while consuming power at 17.50 μWcm−2 when cycled at 25 μAcm−2. Our solution-processed technique allows for controllable vacancy implantation and binder-free coating of WO3-x on various substrates. It significantly reduces the processing time and requires low energy consumption, making it a practical and efficient method for enhancing the overall photo-conversion and energy storage performances of WO3-based electrodes.

Enhancing light energy harvesting and storage properties of cellulose acetate/azobenzene films through perylene photosensitization

This study presents a straightforward approach to enhancing the light energy capture and storage properties of cellulose acetate/azobenzene (CA/Azb) films through photosensitization with a perylene derivative (Py). The films' photoisomerization (trans-to-cis) and reverse isomerization (cis-to-trans) behaviors were evaluated under cold white LED light. Incorporating varying concentrations of perylene significantly improved the films' optical performance and energy storage capacity. Notably, the photoisomerization time of CA/Azb/Py films decreased by up to 30% compared to CA/Azb films. Furthermore, the energy storage half-life for films with the highest perylene content reached 70 minutes, substantially longer than that of CA/Azb films (24 minutes). Remarkably, the energy density of the film with the highest perylene content reached 240 J g⁻¹, which is more than 1.7 times higher than that of the CA/Azb film (138 J g⁻¹).

Emerging Advanced Photo‐Rechargeable Batteries

AbstractThe depletion of fossil fuels necessitates the efficient utilization of solar energy and the urgent resolution of its instability, intermittency, and storage challenges. Photo‐rechargeable batteries, which integrate solar cells and energy storage batteries to convert solar energy into electricity and store it as chemical energy, have gradually emerged as a novel research direction to meet the energy demands of various standalone applications such as building facades, mobile transportation devices, and outdoor settings. This review elucidates the device structure, working principles, and key parameters of photo‐rechargeable batteries. Furthermore, various photo‐rechargeable battery systems such as lithium‐ion battery, lithium‐sulfur battery, sodium‐ion battery, zinc‐ion battery, and aluminum‐ion battery are categorized and summarized, detailing their composition, operational mechanisms, and photoelectric performance. Finally, the future research directions of photo‐rechargeable batteries are delineated, advocating for the exploration of dual‐functional materials that integrate light conversion and energy storage. Specifically, emphasis is placed on studying the compatibility between optical and energy storage materials, investigating new battery operation mechanisms under illumination conditions, considering the imperative of achieving high stability and overall efficiency to enhance device performance, and elucidating the future application pathways of these technologies.

(Invited) Semiconductor Nanostructures for Light Energy Conversion

This talk will review some of the key developments of semiconductor quantum dots based light energy conversion. Semiconductor nanostructures are finding new ways to design light energy conversion devices (e.g., thin film solar cells and light emitting devices). The decreased consumption of energy during the manufacture and the lessened use of semiconductor materials lowers the overall carbon footprint with energy payback time less than a year for such devices. The early studies which focused on the synthesis of various semiconductor nanostructures and exploration of their size dependent optical and electronic properties have led to their their integration in high efficiency thin film solar cells.. Unlike solar cell devices, photocatalytic processes are yet to deliver conversion efficiencies and stability that can make them compatible for practical applications. Understanding the limitations imposed by interfacial charge transfer processes remains a key to further advance photocatalytic systems for chemical energy storage. Recent developments in utilizing semiconductor nanostructures for light energy conversion and storage will be discussed.

Delivery and utilization of photo‐energy for temperature control using a light‐driven microfluidic control device at −40 °C

AbstractLow‐temperature energy harvest, delivery, and utilization pose significant challenges for thermal management in extreme environments owing to heat loss during transport and difficulty in temperature control. Herein, we propose a light‐driven photo‐energy delivery device with a series of photo‐responsive alkoxy‐grafted azobenzene‐based phase‐change materials (a‐g‐Azo PCMs). These a‐g‐Azo PCMs store and release crystallization and isomerization enthalpies, reaching a high energy density of 380.76 J/g even at a low temperature of −63.92 °C. On this basis, we fabricate a novel three‐branch light‐driven microfluidic control device for distributed energy recycling that achieves light absorption, energy storage, controlled movement, and selective release cyclically over a wide range of temperatures. The a‐g‐Azo PCMs move remote‐controllably in the microfluidic device at an average velocity of 0.11–0.53 cm/s owing to the asymmetric thermal expansion effect controlled by the temperature difference. During movement, the optically triggered heat release of a‐g‐Azo PCMs achieves a temperature difference of 6.6 °C even at a low temperature of −40 °C. These results provide a new technology for energy harvest, delivery, and utilization in low‐temperature environments via a remote manipulator.

Dependency of chlorophyll fluorescence of in vitro plant of Carlina L. on light conditions during their cultivation

Aim. To investigate the peculiarities of the functioning of the photosynthetic apparatus of plants of Carlina L. species under different light conditions of in vitro cultivation and under natural conditions using the method of induction of fluorescence of chlorophyll a. Methods. Methods of in vitro plants cultivation, a method of inducing fluorescence of chlorophyll a in light-adapted leaves. Results. It has been demonstrated that in vitro conditions reflect the evolved light growth requirements of species. Our previously obtained results regarding a closer match of physiological needs of in vitro plants of the species of Carlina onopordifolia Besser ex Szafer, Kulcz. et Pawt. to light conditions of variant 1.1 have been confirmed. Based on the synthesis of the dynamics of photosynthetic pigment content and their ratios in in vitro plants of Carlina acaulis L., as well as key parameters of fluorescence under different cultivation light conditions, a conclusion has been drawn about the greater alignment of variant 1.1 with the needs of plants of this species. It is hypothesized that in natural conditions, plants of the species of C. onopordifolia and Carlina cirsioides Klokov undergo abiotic stresses, manifested in increased dissipation of light energy into heat and the processes of photo-inhibition. There is significant enhancement in electron transport within the light-harvesting complex and reduction in the efficiency of quantum yield and light energy storage by Photosystem II. The vitality index of these species in their natural growth conditions is found to be half of the commonly accepted optimum value and 1.97–2.96 times lower compared to experimental in vitro plant groups. Conclusions. The obtained results suggest the usefulness of using the chlorophyll fluorescence induction method for assessing the functioning of the photosynthetic apparatus of in vitro plants of the genus Carlina.

Light-dependent metabolic shifts in the model diatom Thalassiosira pseudonana

Diatoms are major producers of carbon and energy in aquatic ecosystems, however their ability to rapidly and successfully acclimate to wide ranging irradiances is poorly understood at the biochemical level. We applied complementary transcriptomic and metabolomic approaches using the model centric diatom Thalassiosira pseudonana to understand mechanisms regulating cell acclimation and growth under high and low light intensities. The integration of these omics data revealed specific mechanisms that shifted carbon and energy fluxes in T. pseudonana depending on light-driven growth rate. To support a growth rate of >1 d−1 in high light, cells upregulated metabolic pathways involved in the production of long chain fatty acids, glycolic acid, and carbohydrates. Under low light, cells maintained a growth rate of ≤0.2 d−1 by conserving photosynthetic energy through upregulation of carbon retention pathways (e.g., gluconeogenesis, glyoxylate cycle). The few significant metabolites detected in low light acclimated cells were associated with light harvesting, energy storage, and signalling. In particular, our metabolite data revealed that eicosanoic acid, a metabolite commonly involved in cellular signalling, may poise light limited cells for fast metabolic remodelling with improving light conditions. The combined physiological, gene expression and metabolite profiling data revealed key metabolic switch points that underpin diatom success and could be leveraged in cell-based models for predictions and manipulations of cell growth or bio-production.

Coupling of formate dehydrogenase to inverse-opal ITO-PSI electrodes for photocatalytic CO2 reduction

Photosynthesis as one of the most fascinating natural processes uses sunlight and CO2 for the preparation of various organic substances. Taking nature as inspiration the present work applies two proteins in an artificial matrix for constructing a biohybrid system allowing light-to-chemical photocataysis. Thus, the protein complexes photosystem I (PSI) and formate dehydrogenase (FDH) are combined with a porous three-dimensional indium tin oxide structure. Direct electron transfer takes place between the electrode material and PSI resulting in cathodic photocurrents. Instead of maximizing the current output, the study focuses on the usage of the excited electrons to drive FDH catalysis. At the enzyme carbon dioxide is reduced to formate with an efficiency of about 15% relative to the number of enhanced photoelectrons. The arrangement is favorable since it enables the conversion of CO2 at rather small applied potential of −0.2 V vs Ag/AgCl and over a longer period of illumination. Conversion efficiency and stability provide a good starting point for further investigations. The reported ITO/PSI/FDH electrode represents a system that combines photocatalysis with enzymatic catalysis allowing the storage of light energy in chemical energy.

Preparation of visible light-WO3/g-C3N4/PANI photocatalyst onto glass and their photocatalytic properties

Wastewater from palm oil industry mostly contains hazardous effluent like palm oil mill effluent (POME) and photocatalytic technology is one of the most effective ways for the degradation of harmful organic pollutants. Nevertheless, the effects of suspended photocatalysts obviously would dwindle the photocatalytic performances. The immobilization of photocatalyst as a newest innovation has received significant attention due to its great potential in terms of recycling, economic, physical–chemical properties, and technological aspects. This paper reports the synthesis of novel WO3/g-C3N4/PANI glass as a retrievable visible-light photocatalyst by simple soft-templating and calcination followed by spin coating with different speed and duration coating. The functional group of O-W-O stretching vibration, hydrophilicity of the immobilized WO3/g-C3N4/PANI glass indicated the presence of WO3/g-C3N4/PANI onto glass was succesfully. The optimum parameters obtained were at a speed of 30 s and duration spinning of 1000 rpm due to the presence of more active sites. In particular, immobilized WO3/g-C3N4/PANI glass showed a good photocatalytic activity in term of decolorization and degradation studies about 25 % and 53 %, respectively, after 7 h under visible light irradiation and energy storage scheme. The results signify possible applications of immobilized WO3/g-C3N4/PANI glass in visible-light-driven and energy-storage-mechanism for a cost-effective treatment of wastewater.

Realizing Attosecond Core-Level X-ray Spectroscopy for the Investigation of Condensed Matter Systems

Unraveling the exact nature of nonequilibrium and correlated interactions is paramount for continued progress in many areas of condensed matter science. Such insight is a prerequisite to develop an engineered approach for smart materials with targeted properties designed to address standing needs such as efficient light harvesting, energy storage, or information processing. For this goal, it is critical to unravel the dynamics of the energy conversion processes between carriers in the earliest time scales of the excitation dynamics. We discuss the implementation and benefits of attosecond soft x-ray core-level spectroscopy up to photon energies of 600 eV for measurements in solid-state systems. In particular, we examine how the pairing between coherent spectral coverage and temporal resolution provides a powerful new insight into the quantum dynamic interactions that determine the macroscopic electronic and optical response. We highlight the different building blocks of the methodology and point out the important aspects for its application from condensed matter studies to materials as thin as 25 nm. Furthermore, we discuss the technological developments in the field of tabletop attosecond soft x-ray sources with time-resolved measurements at the near and extended edge simultaneously and investigate the exciting prospective of extending such technique to the study of 2-dimensional materials.

Self-luminous, shape-stabilized porous ethyl cellulose phase-change materials for thermal and light energy storage

Self-luminous, shape-stabilized porous ethyl cellulose phase-change materials for thermal and light energy storage

Solar utilization beyond photosynthesis.

Natural photosynthesis is an efficient biochemical process which converts solar energy into energy-rich carbohydrates. By understanding the key photoelectrochemical processes and mechanisms that underpin natural photosynthesis, advanced solar utilization technologies have been developed that may be used to provide sustainable energy to help address climate change. The processes of light harvesting, catalysis and energy storage in natural photosynthesis have inspired photovoltaics, photoelectrocatalysis and photo-rechargeable battery technologies. In this Review, we describe how advanced solar utilization technologies have drawn inspiration from natural photosynthesis, to find sustainable solutions to the challenges faced by modern society. We summarize the uses of advanced solar utilization technologies, such asconvertingsolarenergy to electricaland chemicalenergy, electrochemical storage and conversion, and associated thermal tandem technologies. Both the foundational mechanisms and typical materials and devices are reported. Finally, potential future solar utilization technologies are presented that may mimic, and even outperform, natural photosynthesis.

Visible-Light Augmented Lithium Storage Capacity in a Ruthenium(II) Photosensitizer Conjugated with a Dione-Catechol Redox Couple.

Controlling redox activity of judiciously appended redox units on a photo-sensitive molecular core is an effective strategy for visible light energy harvesting and storage. The first example of a photosensitizer - electron donor coordination compound in which the photoinduced electron transfer step is used for light to electrical energy conversion and storage is reported. A photo-responsive Ru-diimine module conjugated with redox-active catechol groups in [Ru(II)(phenanthroline-5,6-diolate)3 ]4- photosensitizer can mediate photoinduced catechol to dione oxidation in the presence of a sacrificial electron acceptor or at the surface of an electrode. Under potentiostatic condition, visible light triggered current density enhancement confirmed the light harvesting ability of this photosensitizer. Upon implementation in galvanostatic charge-discharge of a Li battery configuration, the storage capacity was found to be increased by 100 %, under 470 nm illumination with output power of 4.0 mW/cm-2 . This proof-of-concept molecular system marks an important milestone towards a new generation of molecular photo-rechargeable materials.

Dual-band electromagnetically induced transparent metamaterial with slow light effect and energy storage

The realization of electromagnetically induced transparency (EIT) on metamaterials has special properties, such as strong slow-light, frequency-selection and so on, which have allowed EIT to be widely used in the fields of slow-light, optical storages and filters. In this paper, a metamaterial with two pairs of split ring resonators and one cut-wire is designed to achieve dual-band EIT effect at 0.5–2.14 GHz and 0.4–2.10 GHz with independently tunable bandwidths of 1.64 GHz and 2.7 GHz, respectively. The coupled Lorentz model is adopted to principally study the coupling characteristics between dark and bright modes. It is shown that the coupling strength between the dark and bright modes could be modulated by the coupling distance, which make the dual-band transparent window could be independently modulated by only changing the coupling distance between the bright and dark mode. The group delay and energy storage are also simulated by setting the Gaussian pulse signal passing through the EIT structure. The results show that the group delay of the designed EIT structure is 16.9 times that of the same thickness of dielectric material. The manufactured metamaterial is tested in a microwave anechoic chamber. The experimental and theoretical results are well consistent. These results could be beneficial for the development of EIT research toward some up-and-coming novel slow-light, optical storage, sensor and optical filter applications.

3D porous aerogel based-phase change materials with excellent flame retardancy and shape stability for both thermal and light energy storage

As we all known, the problems of easy leakage, poor thermal conductivity and high flammability will hinder the application of phase change materials for energy storage. In this work, a novel multifunctional composite phase change material was prepared via efficient modifications, which has preeminent flame retardancy and shape stability to achieve safe and efficient storage of heat and light energy. As expected, the composite phase change material had excellent thermal energy storage density (163.9 J/g), even the melting enthalpy ratio could reach 91.1%. In comparison with pure PEG, the thermal conductivity has realized improvement as well, and the shape stability of composite phase change materials was significantly promoted, which could be heated at 80 °C for 1 h without the leakage of PEG. In addition, it showed excellent thermal stability and fire resistance, the maximum decomposition rate and the peak heat release rate were decreased by 47% and 34.1%, respectively, compared with pure PEG. More importantly, composite phase change materials realized the storage of light energy on the basis of thermal energy management and utilization, which could absorb and store ultraviolet and visible light during the day, and then release fluorescence slowly for a long time in the dark. To sum up, neoteric multifunctional composite phase change materials have enormous prospects for safe and efficient application in the fields of solar energy acquisition, thermal and light energy storage and thermal management. • A novel multifunctional composite phase change material was designed. • The composite phase change material had excellent thermal energy storage density, thermal stability and fire resistance. • The maximum decomposition rate and PHRR were decreased by 47% and 34.1%, respectively, compared with pure PEG. • The composite phase change materials realized the simultaneous storage of heat and light energy.

Integration of fully printed and flexible organic electrolyte-based dual cell supercapacitor with energy supply platform for low power electronics

We report the fabrication of flexible, printed dual cell supercapacitors (DCSCs) and their implementations in energy storage units providing peak power to portable devices. The use of organic electrolytes enhances higher capacity in both potential windows (2.5 V/cell) and the temperature ranges than the aqueous electrolytes, while propylene carbonate retains the advantages of low cost and low toxicity. The device delivered capacitance value between 3 and 4 mF, equivalent series resistance < 2 Ω, and very low leakage current of about 0.1 µA. We demonstrated the integration of an organic photovoltaic module (OPV) with an energy supply platform (ESP) and DCSCs for indoor light energy harvesting and storage. The maximum harvested energy was about 39 mJ. The energy is sufficient to provide peak power to portable devices and sensors. This was confirmed by powering an LED with our energy harvesting system. Mechanical deformation testing of DCSCs shows excellent mechanical stability, so that the device is well suited for flexible energy storage units. In a long-term cyclic stability test, the decrease in capacitance value was only 1% of the initial value after 10,000 cycles, indicating good durability and performance.

Influence of g-C3N4 and PANI onto WO3 photocatalyst on the photocatalytic degradation of POME

Presently, the blossoming interest for efficient photocatalytic degradation has come to fruition, which is a promising candidate towards clean energy and a sustainable environment. Introducing doping factor is a great strategy to promote photocatalytic performance of catalysts. For a more effective boost of Aeration-POME (Ae-POME) degradation and efficient photocatalytic visible light absorption, the tungsten trioxide (WO3) was wrapped on graphite carbon nitride (g-C3N4), and the polyaniline (PANI) were prepared using a facile method. The binary photocatalysts was characterized by zeta potential and Fourier-transform infrared spectroscopy (FTIR). As anticipated, WO3/g-C3N4 and WO3/PANI showed excellent catalytic and photocatalytic performance of the color and COD removal of Ae-POME. The WO3/g-C3N4 composite removed color and COD at approximately 30% and 37% of POME, respectively, as compared to WO3/PANI in the absence of light, where less than 30% of color were removed under visible light irradiation and energy storage scheme. In addition, the FTIR studies support the discussions on the effect of doping on POME photocatalytic activity. The significantly enhanced photocatalytic performance is attributed to the synergetic effect of g-C3N4 and PANI, which can create the internal driving force to improve the separation efficiency of charge carriers in WO3. This doping method and the energy storage principle will provide a valuable strategy for the development of a feasible photocatalyst with specific unique structures.

Chromophoric Dendrimer-Based Materials: An Overview of Holistic-Integrated Molecular Systems for Fluorescence Resonance Energy Transfer (FRET) Phenomenon.

Dendrimers (from the Greek dendros → tree; meros → part) are macromolecules with well-defined three-dimensional and tree-like structures. Remarkably, this hyperbranched architecture is one of the most ubiquitous, prolific, and recognizable natural patterns observed in nature. The rational design and the synthesis of highly functionalized architectures have been motivated by the need to mimic synthetic and natural-light-induced energy processes. Dendrimers offer an attractive material scaffold to generate innovative, technological, and functional materials because they provide a high amount of peripherally functional groups and void nanoreservoirs. Therefore, dendrimers emerge as excellent candidates since they can play a highly relevant role as unimolecular reactors at the nanoscale, acting as versatile and sophisticated entities. In particular, they can play a key role in the properties of light-energy harvesting and non-radiative energy transfer, allowing them to function as a whole unit. Remarkably, it is possible to promote the occurrence of the FRET phenomenon to concentrate the absorbed energy in photoactive centers. Finally, we think an in-depth understanding of this mechanism allows for diverse and prolific technological applications, such as imaging, biomedical therapy, and the conversion and storage of light energy, among others.