Pub Date : 2024-10-09DOI: 10.1016/j.est.2024.114073
Lithium-ion battery is the most widely used battery currently, and its reliability and failure under various extreme working environments are therefore widely concerned. Among them, failures resulting from highly dynamic mechanical impacts are the most threatening and less covered by previous research. In this paper, with a specialized Machette hammer impact test system, the irreversible capacity loss of commercial cylindrical jelly-roll lithium-ion batteries under high dynamic mechanical impact was investigated, the influences of impact strength, impact number, and working temperature are also considered. Through microscopic characterization and finite element simulation, the failure mechanisms of anode, cathode, and separator are revealed, and their respective contributions to battery capacity loss are quantitatively analyzed. All these findings provide a theoretical basis for the redundancy design of batteries for missile electro-mechanical systems and other equipment which are subjected to high dynamic mechanical impact conditions.
{"title":"Irreversible failure characteristics and microscopic mechanism of lithium-ion battery under high dynamic strong mechanical impacts","authors":"","doi":"10.1016/j.est.2024.114073","DOIUrl":"10.1016/j.est.2024.114073","url":null,"abstract":"<div><div>Lithium-ion battery is the most widely used battery currently, and its reliability and failure under various extreme working environments are therefore widely concerned. Among them, failures resulting from highly dynamic mechanical impacts are the most threatening and less covered by previous research. In this paper, with a specialized Machette hammer impact test system, the irreversible capacity loss of commercial cylindrical jelly-roll lithium-ion batteries under high dynamic mechanical impact was investigated, the influences of impact strength, impact number, and working temperature are also considered. Through microscopic characterization and finite element simulation, the failure mechanisms of anode, cathode, and separator are revealed, and their respective contributions to battery capacity loss are quantitatively analyzed. All these findings provide a theoretical basis for the redundancy design of batteries for missile electro-mechanical systems and other equipment which are subjected to high dynamic mechanical impact conditions.</div></div>","PeriodicalId":15942,"journal":{"name":"Journal of energy storage","volume":null,"pages":null},"PeriodicalIF":8.9,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142417236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-09DOI: 10.1016/j.est.2024.114042
To investigate the hydraulic characteristics during the start-up process of a full-flow pumped-storage unit (PSU) under low head conditions, numerical simulations and prototype tests were conducted to study the dynamic characteristics during the process. Based on the torque balance equation to control the real-time rotational speed of the runner, an incremental Proportional-Integral-Derivative (PID) algorithm was used to control the guide vanes in real time. Using dynamic mesh technology and computational fluid dynamics (CFD) methods, a numerical simulation of the pump-turbine start-up process was carried out under low-head conditions with PID control. These established the correlation mechanism between the internal flow evolution and external characteristic changes of the pump-turbine. Additionally, the entropy generation theory quantified the energy losses in different regions, including EPDD, EPTD, and EPWS. The results indicated that EPDD and EPTD dominated the entropy generation and were the main causes of hydraulic losses, were basically consistent with the TKE distribution. During the entire start-up process, the combined energy loss ratio of EPDD and EPTD exceeds 80 %, while the maximum proportion of EPWS was only 17 % at 17 s. The distribution characteristics and the generation mode of hydraulic losses were further clarified by combining the transport equation of enstrophy and the flow field distribution. The analysis showed that Gω is the dominant factor leading to vortex formation during the start-up process and is consistent with the spatial distribution of EPR. The region with higher vortex is also the region with higher energy losses. This paper provides a valuable research direction on the start-up process and energy loss change during low-head conditions and lays the foundation for future research to improve the stability and safety of PSUs during the start-up process under low-head conditions.
{"title":"Analysis of hydraulic characteristics during low head start-up transition of pumped storage units based on entropy production theory","authors":"","doi":"10.1016/j.est.2024.114042","DOIUrl":"10.1016/j.est.2024.114042","url":null,"abstract":"<div><div>To investigate the hydraulic characteristics during the start-up process of a full-flow pumped-storage unit (PSU) under low head conditions, numerical simulations and prototype tests were conducted to study the dynamic characteristics during the process. Based on the torque balance equation to control the real-time rotational speed of the runner, an incremental Proportional-Integral-Derivative (PID) algorithm was used to control the guide vanes in real time. Using dynamic mesh technology and computational fluid dynamics (CFD) methods, a numerical simulation of the pump-turbine start-up process was carried out under low-head conditions with PID control. These established the correlation mechanism between the internal flow evolution and external characteristic changes of the pump-turbine. Additionally, the entropy generation theory quantified the energy losses in different regions, including EPDD, EPTD, and EPWS. The results indicated that EPDD and EPTD dominated the entropy generation and were the main causes of hydraulic losses, were basically consistent with the TKE distribution. During the entire start-up process, the combined energy loss ratio of EPDD and EPTD exceeds 80 %, while the maximum proportion of EPWS was only 17 % at 17 s. The distribution characteristics and the generation mode of hydraulic losses were further clarified by combining the transport equation of enstrophy and the flow field distribution. The analysis showed that <em>G<sub>ω</sub></em> is the dominant factor leading to vortex formation during the start-up process and is consistent with the spatial distribution of EPR. The region with higher vortex is also the region with higher energy losses. This paper provides a valuable research direction on the start-up process and energy loss change during low-head conditions and lays the foundation for future research to improve the stability and safety of PSUs during the start-up process under low-head conditions.</div></div>","PeriodicalId":15942,"journal":{"name":"Journal of energy storage","volume":null,"pages":null},"PeriodicalIF":8.9,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142417168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-09DOI: 10.1016/j.est.2024.114060
Eutectogels are an arising material in the field of energy storage applications like high-energy Lithium-Ion batteries (LIBs) due to their properties like higher ionic conductivity, environment friendly and enhanced safety. However, it is important to understand the working mechanism of eutectogels at an atomistic level with the help of Molecular Dynamics (MD) simulations, in order to enhance their performance as electrolytes for LIBs. Eutectogels are formed by integrating deep eutectic solvent (DES) involving Lithium Chloride (LiCl) and ethylene glycol (EG) in the molar ratio of 1:5 with the polymeric matrix of Polyvinyl alcohol (PVA) chains considered for this study. Thereafter, lignin molecules are induced in the eutectogel system to improve the characteristics of an eutectogel. The elaborate study of the effect of lignin on the lithium ions movement through the lignin-added-eutectogel is involved in this work. The increase in hydrogen bonds among PVA polymeric chains and lignin molecules show the strength enhancement. From the Radial Distribution Function results it is derived that the lithium ions are showing enhanced interactions with chlorine ions than any other component of the system. Mean Square Displacement gives an idea about diffusivity of lithium ions through the systems and it suggests that the Li+ ion diffusivity is improved after Lignin imposition. On the basis of findings from this work, the modified Lignin infused PVA based eutectogel can be the potential candidate for the battery and energy storage applications.
{"title":"Lithium ion transportation in lignin infused polyvinyl alcohol based eutectogel: A molecular dynamics framework","authors":"","doi":"10.1016/j.est.2024.114060","DOIUrl":"10.1016/j.est.2024.114060","url":null,"abstract":"<div><div>Eutectogels are an arising material in the field of energy storage applications like high-energy Lithium-Ion batteries (LIBs) due to their properties like higher ionic conductivity, environment friendly and enhanced safety. However, it is important to understand the working mechanism of eutectogels at an atomistic level with the help of Molecular Dynamics (MD) simulations, in order to enhance their performance as electrolytes for LIBs. Eutectogels are formed by integrating deep eutectic solvent (DES) involving Lithium Chloride (LiCl) and ethylene glycol (EG) in the molar ratio of 1:5 with the polymeric matrix of Polyvinyl alcohol (PVA) chains considered for this study. Thereafter, lignin molecules are induced in the eutectogel system to improve the characteristics of an eutectogel. The elaborate study of the effect of lignin on the lithium ions movement through the lignin-added-eutectogel is involved in this work. The increase in hydrogen bonds among PVA polymeric chains and lignin molecules show the strength enhancement. From the Radial Distribution Function results it is derived that the lithium ions are showing enhanced interactions with chlorine ions than any other component of the system. Mean Square Displacement gives an idea about diffusivity of lithium ions through the systems and it suggests that the Li<sup>+</sup> ion diffusivity is improved after Lignin imposition. On the basis of findings from this work, the modified Lignin infused PVA based eutectogel can be the potential candidate for the battery and energy storage applications.</div></div>","PeriodicalId":15942,"journal":{"name":"Journal of energy storage","volume":null,"pages":null},"PeriodicalIF":8.9,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142417170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-09DOI: 10.1016/j.est.2024.113970
Molybdenum disulfide (MoS2) is recognized as a highly promising anode material for lithium-ion batteries (LIBs) due to its two-dimensional layered structure and substantial theoretical specific capacity. The 1 T phase of MoS2, which significantly influences electrochemical performance, offers markedly higher conductivity. However, the metastable nature of 1 T-MoS2 complicates its direct synthesis under standard conditions, making it susceptible to transformation into the less conductive 2H phase through restacking, which in turn degrades its electrochemical properties. This study employed glucose molecules to facilitate the in situ growth of 1 T-rich MoS2 on N-doped graphene via a simple and efficient one-step hydrothermal method. The glucose molecules uniformly insert themselves into the MoS2 interlayers, effectively expanding the interlayer spacing while preserving structural stability and enhancing reaction kinetics. Additionally, the novel interface between carbon-inserted MoS2 and N-doped graphene (NG) creates an efficient transport channel for the rapid transfer of electrons and Li+ ions from graphene to the MoS2 plane. Electrochemical characterization reveals that the MoS2/C@G composite demonstrates excellent bidirectional reaction kinetics and high reversible capacity. Even at a current density of 2 A g−1 after 1000 cycles, the MoS2/C@G composite retains a capacity of 1022.4 mAh g−1. This work proposes a viable strategy for preparing 1 T-rich MoS2-based anode materials, highlighting their significant potential for energy storage device applications.
二硫化钼（MoS2）因其二维层状结构和巨大的理论比容量，被公认为是一种极具潜力的锂离子电池（LIB）负极材料。MoS2 的 1 T 相对电化学性能有重大影响，它具有明显更高的电导率。然而，1 T-MoS2 的易析出性使其在标准条件下的直接合成变得复杂，容易通过重新堆叠转化为导电性较低的 2H 相，进而降低其电化学性能。本研究利用葡萄糖分子，通过简单高效的一步水热法，促进富含 1 T 的 MoS2 在掺杂 N 的石墨烯上原位生长。葡萄糖分子均匀地插入 MoS2 夹层中，有效地扩大了层间间距，同时保持了结构稳定性并提高了反应动力学。此外，插入碳的 MoS2 与掺杂 N 的石墨烯（NG）之间的新型界面为电子和 Li+ 离子从石墨烯到 MoS2 平面的快速转移创造了一个高效的传输通道。电化学特性分析表明，MoS2/C@G 复合材料具有出色的双向反应动力学和高可逆容量。即使在 2 A g-1 的电流密度下循环 1000 次，MoS2/C@G 复合材料仍能保持 1022.4 mAh g-1 的容量。这项工作为制备富含 1 T 的 MoS2 阳极材料提出了一种可行的策略，凸显了它们在储能设备应用中的巨大潜力。
{"title":"1 T-rich MoS2/nitrogen-doped graphene composites: Advanced anode materials to improve the performance of lithium-ion batteries","authors":"","doi":"10.1016/j.est.2024.113970","DOIUrl":"10.1016/j.est.2024.113970","url":null,"abstract":"<div><div>Molybdenum disulfide (MoS<sub>2</sub>) is recognized as a highly promising anode material for lithium-ion batteries (LIBs) due to its two-dimensional layered structure and substantial theoretical specific capacity. The 1 T phase of MoS<sub>2</sub>, which significantly influences electrochemical performance, offers markedly higher conductivity. However, the metastable nature of 1 T-MoS<sub>2</sub> complicates its direct synthesis under standard conditions, making it susceptible to transformation into the less conductive 2H phase through restacking, which in turn degrades its electrochemical properties. This study employed glucose molecules to facilitate the in situ growth of 1 T-rich MoS<sub>2</sub> on N-doped graphene via a simple and efficient one-step hydrothermal method. The glucose molecules uniformly insert themselves into the MoS<sub>2</sub> interlayers, effectively expanding the interlayer spacing while preserving structural stability and enhancing reaction kinetics. Additionally, the novel interface between carbon-inserted MoS<sub>2</sub> and N-doped graphene (NG) creates an efficient transport channel for the rapid transfer of electrons and Li<sup>+</sup> ions from graphene to the MoS<sub>2</sub> plane. Electrochemical characterization reveals that the MoS<sub>2</sub>/C@G composite demonstrates excellent bidirectional reaction kinetics and high reversible capacity. Even at a current density of 2 A g<sup>−1</sup> after 1000 cycles, the MoS<sub>2</sub>/C@G composite retains a capacity of 1022.4 mAh g<sup>−1</sup>. This work proposes a viable strategy for preparing 1 T-rich MoS<sub>2</sub>-based anode materials, highlighting their significant potential for energy storage device applications.</div></div>","PeriodicalId":15942,"journal":{"name":"Journal of energy storage","volume":null,"pages":null},"PeriodicalIF":8.9,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142417229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-08DOI: 10.1016/j.est.2024.114052
The computer-aided estimation of battery state of health (SOH) has been regarded as an active field of energy management because of the high demand for electric vehicles and consumer electronics. In this study, a new data-driven model is proposed for the capacity prediction and online monitoring of lithium-ion batteries, which is formulated based on a kernel support vector machine (KSVM) and a nonlinear Gray Wolf Optimization (NGWO) to capture the health information in electrochemical impedance spectroscopy (EIS) data. The amplitudes of EIS in the frequency range from 0.02 Hz to 20,000 Hz are taken as the input variables of KSVM model to predict the capacity at different cycles of battery charge-discharging. Moreover, GWO is improved through the proposed new inverse S-shaped exponential compound function convergence factor and position ratio-based dynamic weighting scheme to enhance its accuracy in optimizing KSVM parameters. The capacity prediction tasks of single battery (Case 1), different batteries at different temperatures (Case 2) and limited cyclic data (Case 3) are discussed in detail. Experimental results show that compared with other estimation methods, the NGWO-KSVM exhibit the lowest root mean square error (0.073 and 0.075 in Case 1, 0.434 and 0.263 in Case 2), the smallest mean absolute percentage error (0.052 and 0.055 in Case 1, 0.286 and 0.178 in Case 2), and the highest determination coefficient (0.936 and 0.956 in Case 1, and 0.981 and 0.993 in Case 2) for two different batteries in relatively short time. Also the NGWO-KSVM can more effectively utilize a fewer cycles of EIS data to improve capacity estimation performance in Case 3. It provides superior solution for the problem of low accuracy and poor robustness in battery capacity prediction, and has the potential for actual implementation in battery routine monitoring.
{"title":"State-of-health estimation of lithium-ion batteries using a kernel support vector machine tuned by a new nonlinear gray wolf algorithm","authors":"","doi":"10.1016/j.est.2024.114052","DOIUrl":"10.1016/j.est.2024.114052","url":null,"abstract":"<div><div>The computer-aided estimation of battery state of health (SOH) has been regarded as an active field of energy management because of the high demand for electric vehicles and consumer electronics. In this study, a new data-driven model is proposed for the capacity prediction and online monitoring of lithium-ion batteries, which is formulated based on a kernel support vector machine (KSVM) and a nonlinear Gray Wolf Optimization (NGWO) to capture the health information in electrochemical impedance spectroscopy (EIS) data. The amplitudes of EIS in the frequency range from 0.02 Hz to 20,000 Hz are taken as the input variables of KSVM model to predict the capacity at different cycles of battery charge-discharging. Moreover, GWO is improved through the proposed new inverse <em>S</em>-shaped exponential compound function convergence factor and position ratio-based dynamic weighting scheme to enhance its accuracy in optimizing KSVM parameters. The capacity prediction tasks of single battery (Case 1), different batteries at different temperatures (Case 2) and limited cyclic data (Case 3) are discussed in detail. Experimental results show that compared with other estimation methods, the NGWO-KSVM exhibit the lowest root mean square error (0.073 and 0.075 in Case 1, 0.434 and 0.263 in Case 2), the smallest mean absolute percentage error (0.052 and 0.055 in Case 1, 0.286 and 0.178 in Case 2), and the highest determination coefficient (0.936 and 0.956 in Case 1, and 0.981 and 0.993 in Case 2) for two different batteries in relatively short time. Also the NGWO-KSVM can more effectively utilize a fewer cycles of EIS data to improve capacity estimation performance in Case 3. It provides superior solution for the problem of low accuracy and poor robustness in battery capacity prediction, and has the potential for actual implementation in battery routine monitoring.</div></div>","PeriodicalId":15942,"journal":{"name":"Journal of energy storage","volume":null,"pages":null},"PeriodicalIF":8.9,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142417231","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-08DOI: 10.1016/j.est.2024.114023
As the lightest 2D material, monolayer borophene exhibits a specific charge capacity of 1860 mA h g−1 for Li-ion batteries, which is four times higher than that of graphite and is one of the highest specific charge capacities ever reported for 2D anode materials. Additionally, it showed high mechanical strength and a low diffusion barrier. However, monolayer borophene suffers from stability issues in its free-standing form, which restricts its real-life applications. Inspired by the recent experimental investigations, which proved the higher stability of bilayer borophene polymorphs (BBPs) over their monolayer counterparts, in this work, we investigated the dynamical and thermodynamical stabilities of both AA– and AB–stacked BBPs in their β12 phase using first-principles calculations. Between the two stacking patterns, we found that only the AB–stacked β12–BBP is both energetically and dynamically stable, and we further investigated its potential as a high-performance anode material for alkali metal-ion batteries. Our investigations show that AB–stacked β12–BBP exhibits good electrical conductivity before and after metal atom (Li/Na/K) adsorption onto it. Further, AB–stacked β12–BBP adsorbs the metal atoms strongly with adsorption energies ranging between −0.89 to −1.44 eV, indicating that there is a lesser possibility of forming dendrites on this anode. Similarly, it has a low diffusion energy barrier (~ 0.13–0.49 eV) for metal atoms, meeting the fast charge/discharge rate requirements. Moreover, it exhibits a reasonably low average metal-insertion voltage (0.43 to 0.65 V) and a specific charge capacity of 330–413 mA h g−1 that is comparable to graphite. All the above findings suggest that the AB–stacked bilayer β12– borophene can be a potentially favorable anode material.
作为最轻的二维材料，单层硼吩在锂离子电池中的比电荷容量为 1860 mA h g-1，是石墨的四倍，也是迄今为止所报道的二维负极材料中比电荷容量最高的材料之一。此外，它还具有较高的机械强度和较低的扩散阻力。然而，单层硼吩在独立形态下存在稳定性问题，这限制了其在现实生活中的应用。最近的实验研究证明双层硼吩多晶形（BBPs）比单层硼吩多晶形具有更高的稳定性，受此启发，我们在本研究中利用第一原理计算研究了 AA 和 AB 堆叠的 BBPs 在其 β12 相中的动力学和热力学稳定性。在这两种堆叠模式中，我们发现只有 AB 堆叠的 β12-BBP 在能量和动力学上都是稳定的，并进一步研究了它作为碱金属离子电池高性能负极材料的潜力。我们的研究表明，AB-堆积的β12-BBP在吸附金属原子（Li/Na/K）前后均表现出良好的导电性。此外，AB 叠层 β12-BBP 对金属原子的吸附力很强，吸附能介于 -0.89 至 -1.44 eV 之间，这表明在这种阳极上形成树枝状突起的可能性较小。同样，它的金属原子扩散能垒也很低（约 0.13-0.49 eV），符合快速充放电速率的要求。此外，它还表现出相当低的平均金属插入电压（0.43 至 0.65 V）和 330-413 mA h g-1 的比电荷容量，与石墨相当。所有上述发现都表明，AB 叠层双层 β12- 硼吩有可能成为一种有利的负极材料。
{"title":"AB–stacked bilayer β12–borophene as a promising anode material for alkali metal-ion batteries","authors":"","doi":"10.1016/j.est.2024.114023","DOIUrl":"10.1016/j.est.2024.114023","url":null,"abstract":"<div><div>As the lightest 2D material, monolayer borophene exhibits a specific charge capacity of 1860 mA h g<sup>−1</sup> for Li-ion batteries, which is four times higher than that of graphite and is one of the highest specific charge capacities ever reported for 2D anode materials. Additionally, it showed high mechanical strength and a low diffusion barrier. However, monolayer borophene suffers from stability issues in its free-standing form, which restricts its real-life applications. Inspired by the recent experimental investigations, which proved the higher stability of bilayer borophene polymorphs (BBPs) over their monolayer counterparts, in this work, we investigated the dynamical and thermodynamical stabilities of both AA– and AB–stacked BBPs in their <em>β</em><sub>12</sub> phase using first-principles calculations. Between the two stacking patterns, we found that only the AB–stacked <em>β</em><sub>12</sub>–BBP is both energetically and dynamically stable, and we further investigated its potential as a high-performance anode material for alkali metal-ion batteries. Our investigations show that AB–stacked <em>β</em><sub>12</sub>–BBP exhibits good electrical conductivity before and after metal atom (Li/Na/K) adsorption onto it. Further, AB–stacked <em>β</em><sub>12</sub>–BBP adsorbs the metal atoms strongly with adsorption energies ranging between −0.89 to −1.44 eV, indicating that there is a lesser possibility of forming dendrites on this anode. Similarly, it has a low diffusion energy barrier (~ 0.13–0.49 eV) for metal atoms, meeting the fast charge/discharge rate requirements. Moreover, it exhibits a reasonably low average metal-insertion voltage (0.43 to 0.65 V) and a specific charge capacity of 330–413 mA h g<sup>−1</sup> that is comparable to graphite. All the above findings suggest that the AB–stacked bilayer <em>β</em><sub>12</sub>– borophene can be a potentially favorable anode material.</div></div>","PeriodicalId":15942,"journal":{"name":"Journal of energy storage","volume":null,"pages":null},"PeriodicalIF":8.9,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142417234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-08DOI: 10.1016/j.est.2024.114048
Solar dryers are used to dry various agricultural products cleanly and cost-effectively. Their performance can be improved by integrating phase change materials (PCM) for thermal energy storage. This review paper aims to present an up-to-date review of research advancements made on solar dryer technology integrating PCM-based thermal energy storage and highlight future research directions. Experimental and numerical studies are examined and discussed to highlight the potential of PCM for enhancing solar dryer performance, including thermal efficiency and exergy, as well as other performance indicators, including the drying time, extension of the operating drying period, and economic aspects such as payback time. Different dryer types are examined, including direct, indirect, mixed, and hybrid dryers. The survey shows a significant performance enhancement of solar dryers by incorporation of PCM. Further improvement is obtained by the inclusion of nanoparticles and fins into PCM. Finally, research gaps are highlighted at the end of the study for future research, along with concluding points.
{"title":"Performance of various solar dryer types integrating latent heat storage for drying agricultural products: An up-to-date review","authors":"","doi":"10.1016/j.est.2024.114048","DOIUrl":"10.1016/j.est.2024.114048","url":null,"abstract":"<div><div>Solar dryers are used to dry various agricultural products cleanly and cost-effectively. Their performance can be improved by integrating phase change materials (PCM) for thermal energy storage. This review paper aims to present an up-to-date review of research advancements made on solar dryer technology integrating PCM-based thermal energy storage and highlight future research directions. Experimental and numerical studies are examined and discussed to highlight the potential of PCM for enhancing solar dryer performance, including thermal efficiency and exergy, as well as other performance indicators, including the drying time, extension of the operating drying period, and economic aspects such as payback time. Different dryer types are examined, including direct, indirect, mixed, and hybrid dryers. The survey shows a significant performance enhancement of solar dryers by incorporation of PCM. Further improvement is obtained by the inclusion of nanoparticles and fins into PCM. Finally, research gaps are highlighted at the end of the study for future research, along with concluding points.</div></div>","PeriodicalId":15942,"journal":{"name":"Journal of energy storage","volume":null,"pages":null},"PeriodicalIF":8.9,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142417540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-08DOI: 10.1016/j.est.2024.114056
Hard carbon (HC) is widely regarded as one of the most promising anode materials for sodium-ion batteries (SIBs), but it still faces several key challenges, including low capacity, poor rate capability, and low initial Coulombic efficiency. To address these issues, in current study, naturally N-doped biomass waste sorghum husk is utilized as a high-quality carbon source to fabricate porous HC materials as anodes for SIBs. This self-doped strategy facilitates electron/ion transport, enhances electrolyte wettability, and significantly improves sodium storage performance, particularly at low temperatures. The synthesized anode electrodes exhibit outstanding performance at −20 °C with a high specific capacity of 322 mA h g−1 at 50 mA g−1 and an initial Coulombic efficiency of 91 %. The abundant porous structure of the material ensures long-term cycling stability, maintaining a capacity of over 150 mA h g−1 after 600 cycles at 1 A g−1. Additionally, the cyclic voltammetry (CV) test results and galvanostatic intermittent titration technique (GITT) confirm that the sodium ion transport is primarily diffusion-controlled, indicating excellent rate capability.
硬碳（HC）被广泛认为是最有前途的钠离子电池（SIB）阳极材料之一，但它仍然面临着几个关键挑战，包括容量低、速率能力差和初始库仑效率低。为解决这些问题，本研究利用天然掺氮生物质废料高粱壳作为优质碳源，制备多孔碳氢化合物材料作为钠离子电池的阳极。这种自掺杂策略可促进电子/离子传输，提高电解质润湿性，并显著改善钠储存性能，尤其是在低温条件下。合成的阳极电极在-20 °C时表现出卓越的性能，在50 mA g-1的条件下，比容量高达322 mA h g-1，初始库仑效率为91%。该材料丰富的多孔结构确保了长期循环稳定性，在 1 A g-1 条件下循环 600 次后，其容量仍能保持在 150 mA h g-1 以上。此外，循环伏安法（CV）测试结果和电静电间歇滴定技术（GITT）证实，钠离子的传输主要是由扩散控制的，这表明该材料具有出色的速率能力。
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Pub Date : 2024-10-08DOI: 10.1016/j.est.2024.114016
The pumped storage power station is a complex hydraulic-mechanical-electric coupling system. The coupling effect between subsystems causes the pumped storage power stations to exhibit multi-frequency oscillation characteristics, making stable operation challenging. However, the widely-used eigenvalue analysis, hydraulic vibration analysis, and the Fourier transform methods cannot comprehensively distinguish and quantify the multi-frequency oscillation characteristics of pumped storage power stations. This study aimed to propose a theoretical analysis method to comprehensively investigate the multi-frequency oscillation characteristics and their main influencing factors. First, the mathematical model of a pumped storage power station with upstream and downstream surge tanks was established. Then, a multi-frequency oscillation method for deriving the theoretical formula for the dynamic response was introduced, and verified via numerical simulation. The dominant oscillations in the dynamic response were accurately identified. The results showed that the system was supposed by six frequency oscillations (S1 - S6), and the dynamic response of the rotational speed consisted of a major wave and a tail wave. The major wave was determined by the S1 and S6 oscillations, and the tail wave was determined by the S3 oscillation. Finally, the main factors influencing the multi-frequency oscillations were investigated. The governor parameters and penstock water inertia significantly influenced the S1 and S6 oscillations and thus the major wave. The tailrace tunnel water inertia significantly influenced the S3 oscillation and thus the tail wave. Overall, the proposed method not only enhances our understanding of hydraulic-mechanical-electric coupling multi-frequency oscillations, but also has important engineering value for ensuring the stable operation of pumped storage power stations.
{"title":"Multi-frequency oscillation characteristics and stability of the pumped storage power station based on a theoretical analytical method","authors":"","doi":"10.1016/j.est.2024.114016","DOIUrl":"10.1016/j.est.2024.114016","url":null,"abstract":"<div><div>The pumped storage power station is a complex hydraulic-mechanical-electric coupling system. The coupling effect between subsystems causes the pumped storage power stations to exhibit multi-frequency oscillation characteristics, making stable operation challenging. However, the widely-used eigenvalue analysis, hydraulic vibration analysis, and the Fourier transform methods cannot comprehensively distinguish and quantify the multi-frequency oscillation characteristics of pumped storage power stations. This study aimed to propose a theoretical analysis method to comprehensively investigate the multi-frequency oscillation characteristics and their main influencing factors. First, the mathematical model of a pumped storage power station with upstream and downstream surge tanks was established. Then, a multi-frequency oscillation method for deriving the theoretical formula for the dynamic response was introduced, and verified via numerical simulation. The dominant oscillations in the dynamic response were accurately identified. The results showed that the system was supposed by six frequency oscillations (<em>S</em><sub>1</sub> - <em>S</em><sub>6</sub>), and the dynamic response of the rotational speed consisted of a major wave and a tail wave. The major wave was determined by the <em>S</em><sub>1</sub> and <em>S</em><sub>6</sub> oscillations, and the tail wave was determined by the <em>S</em><sub>3</sub> oscillation. Finally, the main factors influencing the multi-frequency oscillations were investigated. The governor parameters and penstock water inertia significantly influenced the <em>S</em><sub>1</sub> and <em>S</em><sub>6</sub> oscillations and thus the major wave. The tailrace tunnel water inertia significantly influenced the <em>S</em><sub>3</sub> oscillation and thus the tail wave. Overall, the proposed method not only enhances our understanding of hydraulic-mechanical-electric coupling multi-frequency oscillations, but also has important engineering value for ensuring the stable operation of pumped storage power stations.</div></div>","PeriodicalId":15942,"journal":{"name":"Journal of energy storage","volume":null,"pages":null},"PeriodicalIF":8.9,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142417237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-08DOI: 10.1016/j.est.2024.113904
Supercapacitors have emerged as an essential component for energy storage applications, providing higher power densities and longer cycle life than batteries. Among various supercapacitor materials, manganese dioxide (MnO2) has attracted considerable attention because of its abundance, environmental friendliness, and good electrochemical characteristics. In this study, we present a simplistic chemical synthesis route for the fabrication of δ phase of MnO2 with a sea urchin-like morphology. The synthesized MnO2 device shows remarkable electrochemical performance with about 90 % of retention. While there has been little investigation into how environmental conditions, such as light, impact the capacitive performance of semiconductor materials. Our research aims to address this gap, and we demonstrated significant 46 % increase in capacitance of MnO2 when exposed to light. During the study we observed photoresponsivity of MnO2 electrode, therefore, the electrode could be used as a self-powered photodetector. Finally, we reveal the effectiveness of nanostructured δ-MnO2 flexible electrodes in symmetrical supercapacitor devices, highlighting the potential of MnO2-based materials to further energy storage technology with the help of light.
{"title":"Unveiling light-modulated capacitance of sea urchin like δ-MnO2: A smart flexible photocapacitive device","authors":"","doi":"10.1016/j.est.2024.113904","DOIUrl":"10.1016/j.est.2024.113904","url":null,"abstract":"<div><div>Supercapacitors have emerged as an essential component for energy storage applications, providing higher power densities and longer cycle life than batteries. Among various supercapacitor materials, manganese dioxide (MnO<sub>2</sub>) has attracted considerable attention because of its abundance, environmental friendliness, and good electrochemical characteristics. In this study, we present a simplistic chemical synthesis route for the fabrication of δ phase of MnO<sub>2</sub> with a sea urchin-like morphology. The synthesized MnO<sub>2</sub> device shows remarkable electrochemical performance with about 90 % of retention. While there has been little investigation into how environmental conditions, such as light, impact the capacitive performance of semiconductor materials. Our research aims to address this gap, and we demonstrated significant 46 % increase in capacitance of MnO<sub>2</sub> when exposed to light. During the study we observed photoresponsivity of MnO<sub>2</sub> electrode, therefore, the electrode could be used as a self-powered photodetector. Finally, we reveal the effectiveness of nanostructured δ-MnO<sub>2</sub> flexible electrodes in symmetrical supercapacitor devices, highlighting the potential of MnO<sub>2</sub>-based materials to further energy storage technology with the help of light.</div></div>","PeriodicalId":15942,"journal":{"name":"Journal of energy storage","volume":null,"pages":null},"PeriodicalIF":8.9,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142419899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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