High Energy Storage Capability Research Articles

Cotton functionalized with polyethylene glycol and graphene oxide for dual thermoregulating and UV-protection applications

A thermoregulating smart textile based on phase change material (PCM) polyethylene glycol (PEG) was prepared by chemically grafting carboxyl-terminated PEG onto cotton. Further deposits of graphene oxide (GO) nanosheets were made on the PEG grafted cotton (PEG-g-Cotton) to improve the thermal conductivity of the fabric and to block harmful UV radiation. The GO-PEG-g-Cotton was characterized by Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), Raman spectroscopy, X-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), and field emission-scanning electron microscopy (FE-SEM). With an enthalpy of 37 and 36 J/g, respectively, the DSC data revealed that the functionalized cotton's melting and crystallization maxima occurred at 58 °C and 40 °C, respectively. The thermogravimetric analysis (TGA) presented that GO-PEG-g-Cotton was thermally more stable in comparison to pure cotton. The thermal conductivity of PEG-g-Cotton increased to 0.52 W/m K after GO deposition, while pure cotton conductivity was measured as 0.045 W/m K. The improvement in the UV protection factor (UPF) of GO-PEG-g-Cotton was observed indicating excellent UV blocking. This temperature-regulating smart cotton offers a high thermal energy storage capability, better thermal conductivity, thermal stability, and excellent UV protection.

Lead-free bismuth pyrochlore-based dielectric films for ultrahigh energy storage capacitors

We developed ultra-high energy storage density capacitors using a new class of lead-free bismuth pyrochlore-based dielectric film material systems with high breakdown strength and reliability. The 2 μm-thick pyrochlore ceramic film capacitors have demonstrated ultra-high energy densities around 90 J/cm3 with very low energy loss below 3%, which is achieved by the combination of high permittivity, pseudo-linear dielectric characteristics, and high breakdown electric field over 4.5 MV/cm. Particularly, these pyrochlore ceramic films can endure voltage strength up to ∼900 V. These noteworthy pyrochlore ceramic films are fabricated by the low-cost chemical solution deposition process which allows dielectric films to be processed on standard platinized silicon wafers. This new class of capacitors can satisfy the emergent needs for significant reduction in size and weight of capacitors with high energy storage capability in power electronics, electric vehicles, and energy storage in sustainable energy systems. Our research provides a unique and economical platform for the processing of this useful pyrochlore material in large volume for eco-friendly energy applications.

Supersonically sprayed self-aligned rGO nanosheets and ZnO/ZnMn2O4 nanowires for high-energy and high-power-density supercapacitors

• ZnO nanospheres and ZnMn 2 O 4 nanowires were produced by a hydrothermal method for supercapacitor applications • The MnSO 4 concentration was varied from 0.05 to 0.15 mol/L to identify the electrode with the highest capacitance. • The optimal electrode exhibited a specific capacitance of 276.3 mF cm −2 at a current density of 0.5 mA cm −2 . • The highest energy density was 98.2 μWh cm −2 at a power density of 1600 μW cm −2 . Core-shell-type bimetallic oxide and carbon composites comprising zinc oxide (ZnO) nanospheres and zinc manganese oxide (ZnMn 2 O 4 ) nanowires were produced by a hydrothermal method, and supersonically sprayed together with reduced graphene oxide (rGO) nanosheets onto Ni foil to fabricate flexible supercapacitors. The supersonic impact facilitated the exfoliation of the rGO nanosheets, thereby increasing the surface area and adhesion of the composite particles to the substrate. The rGO nanosheets were vertically aligned during the supersonic impact and formed localized zones, enabling optimal accommodation of the ZnO/ZnMn 2 O 4 particles. This localization, with the addition of rGO, reduced the agglomeration of ZnO/ZnMn 2 O 4 particles. The molar concentration of MnSO 4 used in the synthesis of ZnO/ZnMn 2 O 4 was varied from 0.05 to 0.15 mol/L to determine the optimal MnSO 4 concentration that would result in the highest energy storage capacitance. The unique nanostructure of ZnO/ZnMn 2 O 4 and the self-alignment of rGO sheets facilitated a favorable environment for high energy storage capability with a specific capacitance of 276.3 mF cm −2 at a current density of 0.5 mA cm −2 and an energy density of 98.2 μWh cm −2 at a power density of 1600 μW cm −2 . The width of the potential window was increased to 1.2 V, implying a significant increase in the energy storage capability of the supercapacitor. Capacitance retention of 88% was achieved after 10,000 charge/discharge cycles for the supercapacitor fabricated using an optimal MnSO 4 concentration (0.10 mol/L) during the composite synthesis.

Robust and Elastic Bioinspired MXene‐Coated Foams with Enhanced Energy Storage and Conversion Capabilities

AbstractConstructing highly porous structures using Ti3C2Tx MXene provides a promising strategy toward achieving low density, high specific surface area, and shorter ion/molecule transport paths. However, the weak MXene‐MXene or MXene‐substrate interactions hinder the development of ultra‐robust and elastic MXene‐based architectures. To address this issue, a bio‐inspired strategy is developed to effectively adhere the MXene nanosheets onto melamine foam via covalent and hydrogen bonding interactions through polyethyleneimine/polydopamine‐modification. The enhanced interactions contribute to high MXene loading (≈94 wt.%) and reversible compressibility even after 10 000 compression/release cycles at 80% strain. The compressible supercapacitor device assembled from this foam exhibits high energy storage capability (119 F g−1 at 2 mV s−1) with capacitance retention of ≈93% after 1000 compression/release cycles at 50% strain. Moreover, the presence of polydopamine and MXene enable the absorption of light in the UV–Vis and near‐IR regions, respectively, inducing photothermal conversion functionality, with an evaporation rate of ≈1.5 kg m−2 h−1 and ≈89% solar evaporation efficiency under one sun illumination. It is envisaged that this bio‐inspired chemical modification offers a versatile strategy for the assembly of MXene nanosheets onto different substrates for various applications, such as electromagnetic interference shielding, energy storage, and conversion.

Stretchable MXene based films towards achieving balanced electrical, mechanical and energy storage properties

Ti3C2Tx MXene with superior electrical, mechanical and electrochemical properties has attracted tremendous interest in flexible electronics. However, it remains challenging to transfer these prominent properties to stretchable MXene films with uncompromising properties due to the small flake size and weak interlayer interactions of MXene. Here, by using large sized MXene (LMX, ∼10 μm) with continuous overlap rate, and the synergistic effects of covalent and hydrogen bonds between PVA and LMX, we achieve stretchable polyvinyl alcohol (PVA)/LMX films that can simultaneously possess high mechanical strength (∼280 MPa), electrical conductivity (∼6240 S cm−1) and energy storage capability (∼364F g−1) under different tensile strains ranging from 0 to 150 %. The as-assembled stretchable supercapacitor device demonstrates high capacitance retention of nearly 100 % under stretching rates at 50 %, 100 % and 150 %, or bending rates at 90° and 180°. Impressively, the device also displays good reliability and safety that can maintain its performances under repeated stretching (at 100 % strain) or bending (180°) after 1000 cycles. Thus, the development of stretchable MXene based films with uncompromised properties is expected to broaden their applications for wearable electronics in future commercialization.

Compression-tolerant supercapacitor based on NiCo2O4/Ti3C2Tx MXene/reduced graphene oxide composite aerogel with insights from density functional theory simulations

Compression-tolerant electrodes are critical for developing next-generation wearable energy storage devices. However, most of previous studies on compressible electrodes focus on carbon-based materials, whereas metal-based materials such as spinel metal oxide with faradaic nature have been rarely studied due to their lack of compressibility. Herein, NiCo2O4 (NCO) microtubes assembled by ultrathin and mesoporous nanosheets, are deposited on/into Ti3C2Tx MXene/reduced graphene oxide aerogel (MGA), an intrinsically compressible host template with high conductivity and specific surface areas. The optimized NCO/MGA-300 sample shows a reversible compressive strain of 60% and a superior durability. Density functional theory (DFT) calculations reveal that the NCO/MGA-300 heterojunction has high electronic conductivity, fast electron transfer ability, and low adsorption energy for OH– ions. As a result, the NCO/MGA-300 electrode exhibits superb electrochemical performance in terms of its high gravimetric capacitance (1633F g−1 at 1 A g−1), rate performance (1492F g−1 at 10 A g−1), and remarkable cycling stability of 86.6% after 10,000 charge-discharging cycles. Moreover, an assembled asymmetric supercapacitor based on compressible NCO/MGA-300 shows stable electrochemical performances under different compressive strains (20%. 40% and 60%), or after 100 compression-release cycles. This research finding demonstrates the possibility of metal-based electrode for wearable devices with high energy storage capability and good compressibility.

Ternary structured magnesium cobalt oxide/graphene/polycarbazole nanohybrids for high performance electrochemical supercapacitors

In the present work, polycarbazole (PCz)/magnesium cobalt oxide (MgCo2O4)/reduced graphene oxide (RGO) based ternary nanocomposite was prepared through in-situ polymerization, and utilized it as an active electrodes for electrochemical energy storage supercapacitor applications. The electrochemical behaviour of PCz and its nanocomposites were investigated by measuring specific capacitance using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and Galvanostatic charge–discharge (GCD) analysis. The PCz/MgCo2O4/RGO hybrids exhibited higher capacitance (548.54 F/g) than that of PCz (117.65 F/g) and PCz/MgCo2O4 (482.92 F/g) at the scan rate of 50 mV/s, as determined by CV method. The enhanced supercapacitance indicates high power and energy storage capabilities of the ternary metal oxide-graphene based polycarbazole nanocomposites. Electrochemical impedance spectroscopy confirmed low solution resistance of PCz/MgCo2O4/RGO. Thermogravimetric analysis affirmed the increased thermal stability of PCz/MgCo2O4/RGO composite compared to that of pure polycarbazole and PCz/MgCo2O4 nanocomposite. The scanning electron micrographs of nanocomposite confirmed the successful incorporation of nanofillers into the PCz matrix. On the basis of the research findings, PCz/MgCo2O4/RGO can be expected to be a promising electrode active material for high performance energy storage supercapacitors.

Metal-organic frameworks mediated interface engineering of polymer nanocomposites for enhanced dielectric constant and low dielectric loss

Interface modulation is a key issue for the incorporation of inorganic nanofillers into polymeric matrixes, especially in the applications of dielectric materials. Metal-organic frameworks (MOFs) with special organic and inorganic characteristics represent enormous potential in the interface engineering of polymer-based nanocomposites with desirable dielectric performance. Herein, we report a novel strategy to synthesize graphene oxide nanosheets with UiO-66-NH2 MOF decoration (G@M) using an in-situ and ex-situ method, which are utilized as the nanofillers in the super-engineering polymeric matrix namely polyarylene ether nitrile (PEN). In-situ MOF decoration improves the compatibility between graphene oxide and PEN matrix, and the resulting G@M/PEN nanocomposite shows an enhanced dielectric constant of 7.94 and an ultra-low dielectric loss of 0.014 (1000 Hz) at a low filling content (4 wt%) with outstanding tensile strength (106 MPa) and high glass transition temperature (208°C). Besides, owing to the in-situ interface tailoring, the G@M/PEN nanocomposite exhibits a much higher energy storage capability, about 107% higher than that of conventional graphene oxide-incorporated nanocomposite. This research provides new insight into the interface design of polymer-based nanocomposites for dielectric applications.

Multivariant Me ions design of Bi(Ni0.5Zr0.5)O3 amorphous thin film with high energy storage capability

The development of advanced pulse power technology proposes higher demand for dielectric energy storage materials. However, simultaneously obtaining high polarization and breakdown strength has become an obstacle to the development of dielectric materials. Herein, through the elaborate design of multivariant ions Me, BiMeO3 system thin film Bi(Ni0.5Zr0.5)O3 integrating high polarization, large breakdown strength and a localized heterostructure, generating an excellent energy storage density of 77.42 J cm−3 and efficiency of 70.29% at 5.60 MV cm−1. The enhancive breakdown strength of Bi(Ni0.5Zr0.5)O3 thin film is mainly attributed to the amorphous phase induced by low preparation temperature and the oxygen vacancy bound by the valence change of Ni2+ ion, which reduces leakage current density. This design approach is expected to be widespread for the development of BiMeO3 system thin film.

Reinforced via the insulative boric oxide in the BaTiO3 amorphous thin film with high energy storage capability and stability

Dielectric film capacitors are considered as a potential candidate for advanced power electronics technology due to their fast charging and discharging rate and stability. However, the further improvement of energy storage density is still a major challenge. Herein, a reasonable amorphous structure is applied to the preparation of dielectric film capacitors to improve the dielectric and energy storage properties. The high breakdown strength and energy storage density in the amorphous film are assigned by the disordered structure and intrinsic high insulative for B2O3. As a result, a high discharge energy storage density of 68.64 J cm−3 and an efficiency of 85% can be achieved in the BaTiO3-5wt%B2O3 amorphous thin film at 7.3 MV cm−1, together with excellent thermal stability (20–200 °C) and cyclic stability (up to 105 times) This work provides a paradigmatic method to achieve high energy storage density and stability.

Scalable fabrication of quantum-sized CoS1.97 nanoparticles anchoring on biomass carbon aerogel for energy storage application

Exploiting earth-abundant and cost-efficient electrode materials is an effective strategy to fulfil the urgent demand for high-efficiency energy-storage. Carbon aerogels (CAs) with conductive skeleton and large specific area have attracted significant attention in electrode materials. However, how to achieve the large-scale production of CAs with both high energy storage capability and reasonable cost still remains a challenge. Herein, a scalable and cost-effective route toward constructing cobalt sulfide nanoparticles/carbon aerogel (CoS1.97/CA) hybrid electrode is described. Quantum-sized CoS1.97 nanoparticles are synthesized by in situ selective vulcanization of Co2+ absorbed on the carbonaceous watermelon tissues which acts as current collector for the fast electrons transfer. Quantum-sized CoS1.97 nanoparticles provide abundant active sites for the redox reaction with electrolyte ions in the hybrid electrode, thus leading to an excellent electrochemical capacity of 1715 C g−1. Furthermore, an asymmetric supercapacitor is assembled by employing CoS1.97/CA-500 as positive electrode and CA as negative electrode, which delivers the highest capacity of 51.5 mAh g−1 and energy density of 36.4 Wh kg−1. In addition, an impressive cycling span of 20000 cycles is obtained with capacity retention reaching up to 98.9%, demonstrating its high stability for real-world application. These findings demonstrate the bio-inspired and cost-effective development of 3D carbon aerogel electrode for incorporating with other novel materials for the applications in energy storage.

Geochemical and energy storage properties of natural stones belong to limestone and Fe-shale families

In recent years, the rapidly increasing search for compact, sustainable, and low-cost energy storage systems has led researchers to seek natural materials with high energy storage capability. Taking motivation from this point, our study has been focused on examining the physical, chemical, and dielectric properties of Kayseri Limestone (LS-K), Yahyalı stone (YS), and Edirne Limestone (LS-E) which have been collected from different regions of Turkey mines. The chemical content and structure of the stones have been determined by X-Ray Fluorescence analyzer and Fourier Transform Infrared spectrometry. The surface morphologies have also been visualized by Scanning Electron Microscope images. The frequency dependences of the components of complex permittivity, impedance, and ac conductivity have been examined at room temperature. It has been reported that LS-E has the greatest ε′ value at 1–100 Hz interval. On the other hand, LS-K stands out as a low dielectric loss material with ε″ values approximately 30 times and 24 times lower than YS and LS-E in the low-frequency range, respectively. Moreover, although the LS-K cannot have as high ε′ values as the LS-E in the low-frequency region, it exhibits super-capacitive properties in a wide high-frequency interval of 47 kHz-40 MHz. The super-capacitive behavior of the LS-K has manifested itself with a phase angle of almost −90°. In particular, the LS-K that has ε″ values of 0.02 and less in the frequency interval of 0.1 MHz–40 MHz becomes an inexpensive and natural promising candidate for high-frequency energy storage applications.

High-performance and flexible lithium-ion battery anodes using modified buckypaper

Conventional electrodes for lithium ion batteries, represented as the electrode films casted on the metal foil, are struggling to fulfill the requirements for the flexible electronics due to their heavy, thick, rigid, and brittle structure, which can lead to the deterioration of electrical contact followed by low cycling stability under the repeating mechanical stress. Therefore, development of stable and flexible electrodes is of crucial demand for the implementation of lithium ion batteries to the flexible electronic devices. In this study we demonstrate that the flexible and light buckypaper with high electrical conductivity is the promising alternative to the metal current collectors. In addition, the high capacity anode based on SiO2 nanoparticles is introduced to the functionalized buckypaper. Our electrode reveals high energy storage capability (1101 mAh/g) even after 300 cycles. The composite electrode can be considered the potential high-performance anode for flexible electronic devices.

Microcapsules of n-dodecanoic acid/melamine-formaldehyde with enhanced thermal energy storage capability for solar applications

A new bio-based microencapsulated phase change material (MEPCM) was synthesised by an in situ polymerisation method, and its thermal energy storage properties were experimentally studied. Bio-based n-dodecanoic acid with a high heat storage capacity was encapsulated by a melamine-formaldehyde (MF) polymeric shell. The MEPCM was characterised using field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and thermal conductivity analysis (TCA). The microcapsules had a perfectly spherical morphology with a core–shell microstructure. The MEPCM was chemically stable, and its crystallinity was unaltered. Dodecanoic acid encapsulated by the MF shell exhibited a high thermal energy storage capability of 99.3% and was observed to melt at 41.8 °C with a decent enthalpy of 41.7 kJ/kg. The prepared microcapsules were thermally stable up to 165.02 °C, which were also observed to be leak-proof well above the phase transition temperature. Furthermore, the thermal reliability of the MEPCM was good after 1000 thermal cycles. Overall, the MEPCM was a viable candidate for medium-temperature thermal energy storage applications.

Pokeweed leaves derived materials for high-energy-density asymmetric supercapacitor

Biomass derived energy storage materials with unique structure, chemical composition, and surface property have become a research hotspot. Herein, pokeweed leaves with high manganese enrichment ability are used for the preparation of activated carbon (AC) and mixed oxides (MO), which are used as the negative and positive electrodes for hybrid supercapacitor. Benefiting from the highly porous structure, the AC and MO samples exhibit high energy storage capability. The optimized AC-700 exhibits a high specific capacitance of 317.3 F∙g−1 at 0.5 A∙g−1 and excellent cycling stability with 90.8 % capacitance retention after 10,000 cycles. Furthermore, the MO-500//AC-700 asymmetric supercapacitor (ASC) fabricated by MO-500 and AC-700 displays high energy and power density (70.3 Wh∙kg−1 at 793.9 W∙kg−1) as well as excellent cyclic stability (91 % capacitance retention after 10,000 cycles), suggesting a high energy storage performance. The present work supplies a facile and efficient strategy for the preparation of high performance supercapacitor materials by using biomass with high metal enriching ability.

Experimental investigations on the design of a dual-media thermal energy storage with liquid metal

Liquid metals are a promising heat transfer fluid with stability over a wide temperature range and high thermal conductivity. In concentrating solar energy power plants, as well as in the steel processing facilities heat is generated at high temperature level. Many fluids begin to decompose at such high temperatures and gases have poor thermal conductivity, making it difficult to effectively store and extract heat from the source. Liquid metal heat transfer fluids are able to effectively transport energy at a wide range of temperatures (150 ∘C–1000 ∘C). Existing heat transfer fluids, such as molten salts, have a working range between 290 ∘C and 565 ∘C for example. Depending on the metal selected, thermal conductivity can be 30 to 100 times higher than molten salts, but liquid metals have lower energy density. The liquid metal can be paired with a filler material having a higher energy density to develop a system with high energy transport and storage capability. The first lab-scale experiment of thermocline energy storage with liquid metal as a heat transfer fluid and a zirconium silicate filler, called VESPA [Vorversuch EnergieSPeicher Aufbau (ger.), engl. Preliminary test for energy storage setup], was carried out to prove the concept. So far, there are promising, yet only numerical investigations of thermocline energy storage with liquid metal as heat transfer fluid. The storage system under investigation was a dual-media thermocline energy storage system with liquid lead–bismuth eutectic as heat transfer fluid and zirconium silicate as filler material. The experiments were executed at temperatures from 180 ∘C to 380 ∘C, and focused on design aspects of the energy storage system. Different modes of operation of the storage system were investigated, including charging, discharging, and stand-by. Results are presented showing changes in the vertical temperature profile of the energy storage while varying mass flow, inlet temperature, and filler material.

Achieving high energy storage performance in BiFeO3@TiO2 filled PVDF-based composites with opposite double heterojunction via electric field tailoring

Polymer-based dielectric capacitors are well recognized for high energy density and efficiency. However, the energy density is restricted by the deterioration of breakdown strength with excessive addition of inorganic fillers. Herein, an innovative design of the lamellar-structured BiFeO3@TiO2 (BFO@TO) fillers is proposed and a small amount of BFO@TO is added into P(VDF-HFP)/PMMA blended polymer to fabricate BFO@TO-P(VDF-HFP)/PMMA composites, which delivers an outstanding energy density of 19.3 J cm−3 at 549.2 kV mm−1. The filler possesses a BFO/TO/BFO triple-layered structure. Due to the different Fermi level, electrons are injected from TO into BFO to form electron accumulation layer and construct the heterojunction electric fields between TO and BFO layers. Heterojunction electric fields at two interfaces produced by the triple-layered structure are opposite. The opposite double heterojunction can withstand larger external electric field and improve the breakdown strength. Besides, BFO, as a narrow bandgap semiconductor, is easier for electrons and holes to separate, which further widens the width of the built-in electric field and reduces the dielectric breakdown. Electric field distribution simulations intuitively confirm the enhancement of the breakdown strength. The results provide an effective strategy to address the critical issue of improving the breakdown strength for high energy storage capability.

Excellent energy storage properties achieved in PVDF-based composites by designing the lamellar-structured fillers

Polymer-based dielectrics are widely utilized due to the high power density, fast discharging-charging speed and broad operating temperature range. However, suffering from the inherent low energy density, the practical application is restricted. Herein, a novel structure design of lamellar-structured MgO and BiFeO3/MgO (BFO/MgO) fillers is proposed and a series of PVDF-based composites are fabricated. The breakdown strength is significantly improved due to the large heterojunction electric field produced by BFO and MgO. Meanwhile, the large polarization contributes to a high energy storage performance. A high energy density of 9.93 J cm−3 at 409.6 kV mm−1 with energy efficiency of 66% is achieved in 0.9 wt% BFO/MgO-PVDF/PMMA composites. Compared with previous literatures, high energy density is obtained in a relatively low electric field in this work at such trace filling content, which is quite suitable for the long-term electric field application. This work establishes a facile and effective approach for developing the flexible dielectric capacitors with high energy storage capability.

Stabilized multifunctional phase change materials based on carbonized Cu‐coated melamine foam/reduced graphene oxide framework for multiple energy conversion and storage

AbstractThe leakage of organic phase change materials (OPCMs) at temperatures above their melting point severely limits their large‐scale application. The introduction of porous supports has been identified as an efficient leakage‐proofing method. In this study, a novel carbonized Cu‐coated melamine foam (MF)/reduced graphene oxide (rGO) framework (MF/rGO/Cu‐C) is constructed as a support for fabricating stabilized multifunctional OPCMs. MF serves as the supporting material, while rGO and Cu act as functional reinforcements. As a thermal energy storage material, polyethylene glycol (PEG) is encapsulated into MF/rGO/Cu‐C through a vacuum‐assisted impregnation method to obtain PEG@MF/rGO/Cu‐C composite with excellent comprehensive performance. PEG@MF/rGO/Cu‐C exhibits high phase change enthalpies of 148.3 J g−1 (melting) and 143.9 J g−1 (crystallization), corresponding to a high energy storage capability of 92.7%. Simultaneously, MF/rGO/Cu‐C endues the composite with an enhanced thermal conductivity of 0.4621 W m−1 K−1, which increases by 463% compared to that of PEG@MF. Furthermore, PEG@MF/rGO/Cu‐C displays great light‐to‐thermal and electric‐to‐thermal conversion capabilities, thermal cycle stability, light‐to‐thermal cycle stability, and shape stability, showing promising application prospects in different aspects.

Size effect at discharging process of coconut oil as latent thermal energy storage

Coconut oil is one of the organic PCM materials with high thermal energy storage capability in the form of sensible and latent heat. Ideally, the latent heat storage occurs at a relatively constant temperature associated with phase change transition. Due to relatively low thermal conductivity, the size effect is important to optimize material performance, particularly at the discharging process related to latent heat release. This study will show the simulation results of the size effect in the solidification process of coconut oil by using ANSYS FLUENT. Three plastic balls with radii 2 cm, 3 cm, and 6 cm filled with coconut oil solidified from 308 K to 293 K, and several temperature detectors were placed in the ball to study the heat exchange process. The input parameters of density, heat capacity, thermal conductivity, and viscosity were taken from previous experimental studies. We reported the time evolution of temperature and liquid fraction until the molten coconut oil solidified from different detector positions in each ball.