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Keywords = FePO4

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15 pages, 560 KiB  
Article
Exploring the Material Feasibility of a LiFePO4-Based Energy Storage System
by Caleb Scarlett and Vivek Utgikar
Energies 2025, 18(15), 4102; https://doi.org/10.3390/en18154102 (registering DOI) - 1 Aug 2025
Abstract
This paper analyzes the availability of lithium resources required to support a global decarbonized energy system featuring electrical energy storage based on lithium iron phosphate (LFP) batteries. A net-zero carbon grid consisting of existing nuclear and hydro capacity, with the balance being a [...] Read more.
This paper analyzes the availability of lithium resources required to support a global decarbonized energy system featuring electrical energy storage based on lithium iron phosphate (LFP) batteries. A net-zero carbon grid consisting of existing nuclear and hydro capacity, with the balance being a 50/50 mix of wind and solar power generation, is assumed to satisfy projected world electrical demand in 2050, incorporating the electrification of transportation. The battery electrical storage capacity needed to support this grid is estimated and translated into the required number of nominal 10 MWh LFP storage plants similar to the ones currently in operation. The total lithium required for the global storage system is determined from the number of nominal plants and the inventory of lithium in each plant. The energy required to refine this amount of lithium is accounted for in the estimation of the total lithium requirement. Comparison of the estimated lithium requirements with known global lithium resources indicates that a global storage system consisting only of LFP plants would require only around 12.3% of currently known lithium reserves in a high-economic-growth scenario. The overall cost for a global LFP-based grid-scale energy storage system is estimated to be approximately USD 17 trillion. Full article
(This article belongs to the Collection Renewable Energy and Energy Storage Systems)
13 pages, 1267 KiB  
Article
Toward Green Substitutes: Electrochemical Properties of Conductive Inks Containing Biochar
by Gordana Stevanović, Jovan Parlić, Marija Ajduković, Nataša Jović-Jovičić, Vojkan Radonjić and Zorica Mojović
Sustain. Chem. 2025, 6(3), 21; https://doi.org/10.3390/suschem6030021 - 31 Jul 2025
Abstract
Dry Turkish oak (Quercus cerris) sawdust, untreated and treated with three activators, (H3PO4, NaOH and H2O2) was pyrolyzed under limited-oxygen conditions to obtain biochar samples. The electrochemical properties of these samples were tested [...] Read more.
Dry Turkish oak (Quercus cerris) sawdust, untreated and treated with three activators, (H3PO4, NaOH and H2O2) was pyrolyzed under limited-oxygen conditions to obtain biochar samples. The electrochemical properties of these samples were tested and compared to the properties of several commercial carbon blacks. The electrochemical characterization was performed via cyclic voltammetry, analyzing the response toward two commonly used redox probes, [Fe(CN)6]3−/−4− and [Ru(NH3)6]2+/3+. The influence of the scan rate on this response was investigated, and the resulting data were used to obtain the values of the heterogenous charge transfer constant, k0. Higher k0 values were observed for carbon blacks than for investigated biochar samples. The detection of 4-nitrophenol and heavy metal ions was used to assess the applicability of biochars for electroanalytical purposes. The response of untreated biochar was comparable with the response of Vulcan carbon black, which showed the best response of all analyzed carbon blacks. Full article
11 pages, 1401 KiB  
Communication
Graphene-Enhanced FePO4 Composites with Superior Electrochemical Performance for Lithium-Ion Batteries
by Jinde Yu, Shuchun Hu, Yaohan Zhang, Yin Liu, Wenjuan Ren, Aipeng Zhu, Yanqi Feng, Zhe Wang, Dunan Rao, Yuqin Yang, Heng Zhang, Runhan Liu and Shunying Chang
Materials 2025, 18(15), 3604; https://doi.org/10.3390/ma18153604 (registering DOI) - 31 Jul 2025
Viewed by 37
Abstract
In this study, we successfully synthesized olivine-type FePO4 via an in situ oxidation method and further developed two composite cathode materials (o-FePO4-1/GR-1 and o-FePO4-1/GR-2) by incorporating graphene. The composites were characterized using scanning electron microscopy (SEM), X-ray diffraction [...] Read more.
In this study, we successfully synthesized olivine-type FePO4 via an in situ oxidation method and further developed two composite cathode materials (o-FePO4-1/GR-1 and o-FePO4-1/GR-2) by incorporating graphene. The composites were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray Photoelectron Spectroscopy (XPS), revealing a three-dimensional porous layered structure with an enhanced surface area and strong interaction between FePO4 nanoparticles and graphene layers. Electrochemical tests demonstrated that the composite electrodes exhibited significantly improved performance compared to pristine FePO4, with discharge capacities of 147 mAh g−1 at 1C and 163 mAh g−1 at 0.1C for o-FePO4-1/GR-2, approaching the level of LiFePO4. The incorporation of graphene effectively enhanced the electrochemical reaction kinetics, highlighting the innovation of our method in developing high-performance cathode materials for lithium-ion batteries. Full article
(This article belongs to the Section Electronic Materials)
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26 pages, 3943 KiB  
Article
Effect of Corrosion-Induced Damage on Fatigue Behavior Degradation of ZCuAl8Mn13Fe3Ni2 Nickel–Aluminum Bronze Under Accelerated Conditions
by Ruonan Zhang, Junqi Wang, Pengyu Wei, Lian Wang, Chihui Huang, Zeyu Dai, Jinguang Zhang, Chaohe Chen and Xinyan Guo
Materials 2025, 18(15), 3551; https://doi.org/10.3390/ma18153551 - 29 Jul 2025
Viewed by 226
Abstract
Corrosion fatigue damage significantly affects the long-term service of marine platforms such as propellers. Fatigue testing of pre-corrosion specimens is essential for understanding damage mechanisms and accurately predicting fatigue life. However, traditional seawater-based tests are time-consuming and yield inconsistent results, making them unsuitable [...] Read more.
Corrosion fatigue damage significantly affects the long-term service of marine platforms such as propellers. Fatigue testing of pre-corrosion specimens is essential for understanding damage mechanisms and accurately predicting fatigue life. However, traditional seawater-based tests are time-consuming and yield inconsistent results, making them unsuitable for rapid evaluation of newly developed equipment. This study proposes an accelerated corrosion testing method for ZCuAl8Mn13Fe3Ni2 nickel–aluminum bronze, simulating the marine full immersion zone by increasing temperature, adding H2O2, reducing the solution pH, and preparing the special solution. Coupled with the fatigue test of pre-corrosion specimens, the corrosion damage characteristics and their influence on fatigue performance were analyzed. A numerical simulation method was developed to predict the fatigue life of pre-corrosion specimens, showing an average error of 13.82%. The S–N curves under different pre-corrosion cycles were also established. The research results show that using the test solution of 0.6 mol/L NaCl + 0.1 mol/L H3PO4-NaH2PO4 buffer solution + 1.0 mol/L H2O2 + 0.1 mL/500 mL concentrated hydrochloric acid for corrosion acceleration testing shows good corrosion acceleration. Moreover, the test methods ensure accuracy and reliability of the fatigue behavior evaluation of pre-corrosion specimens of the structure under actual service environments, offering a robust foundation for the material selection, corrosion resistance evaluation, and fatigue life prediction of marine structural components. Full article
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23 pages, 2233 KiB  
Article
A Novel Back Propagation Neural Network Based on the Harris Hawks Optimization Algorithm for the Remaining Useful Life Prediction of Lithium-Ion Batteries
by Yuyang Zhou, Zijian Shao, Huanhuan Li, Jing Chen, Haohan Sun, Yaping Wang, Nan Wang, Lei Pei, Zhen Wang, Houzhong Zhang and Chaochun Yuan
Energies 2025, 18(14), 3842; https://doi.org/10.3390/en18143842 - 19 Jul 2025
Viewed by 261
Abstract
Remaining useful life (RUL) serves as a pivotal metric for quantifying lithium-ion batteries’ state of health (SOH) in electric vehicles and plays a crucial role in ensuring their safety and reliability. In order to achieve accurate and reliable RUL prediction, a novel RUL [...] Read more.
Remaining useful life (RUL) serves as a pivotal metric for quantifying lithium-ion batteries’ state of health (SOH) in electric vehicles and plays a crucial role in ensuring their safety and reliability. In order to achieve accurate and reliable RUL prediction, a novel RUL prediction method which employs a back propagation (BP) neural network based on the Harris Hawks optimization (HHO) algorithm is proposed. This method optimizes the BP parameters using the improved HHO algorithm. At first, the circle chaotic mapping method is utilized to solve the problem of the initial value. Considering the problem of local convergence, Gaussian mutation is introduced to improve the search ability of the algorithm. Subsequently, two key health factors are selected as input features for the model, including the constant-current charging isovoltage rise time and constant-current discharging isovoltage drop time. The model is validated using aging data from commercial lithium iron phosphate (LiFePO4) batteries. Finally, the model is thoroughly verified under an aging test. Experimental validation using training sets comprising 50%, 60%, and 70% of the cycle data demonstrates superior predictive performance, with mean absolute error (MAE) values below 0.012, root mean square error (RMSE) values below 0.017 and mean absolute percentage error (MAPE) within 0.95%. The results indicate that the model significantly improves prediction accuracy, robustness and searchability. Full article
(This article belongs to the Section D: Energy Storage and Application)
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18 pages, 4231 KiB  
Article
Effect Mechanism of Phosphorus-Containing Flame Retardants with Different Phosphorus Valence States on the Safety and Electrochemical Performance of Lithium-Ion Batteries
by Peng Xi, Fengling Sun, Xiaoyu Tang, Xiaoping Fan, Guangpei Cong, Ziyang Lu and Qiming Zhuo
Processes 2025, 13(7), 2248; https://doi.org/10.3390/pr13072248 - 14 Jul 2025
Viewed by 296
Abstract
With the widespread application of lithium-ion batteries (LIBs), safety performance has become a critical factor limiting the commercialization of large-scale, high-capacity LIBs. The main reason for the safety problem is that the electrolytes of LIBs are extremely flammable. Adding flame retardants to conventional [...] Read more.
With the widespread application of lithium-ion batteries (LIBs), safety performance has become a critical factor limiting the commercialization of large-scale, high-capacity LIBs. The main reason for the safety problem is that the electrolytes of LIBs are extremely flammable. Adding flame retardants to conventional electrolytes is an effective method to improve battery safety. In this paper, trimethyl phosphate (TMP) and trimethyl phosphite (TMPi) were used as research objects, and the flame-retardant test and differential scanning calorimetry (DSC) of the electrolytes configured by them were first carried out. The self-extinguishing time of the electrolyte with 5% TMP and TMPi is significantly reduced, achieving a flame-retardant effect. Secondly, the electrochemical performance of LiFePO4|Li half-cells after adding different volume ratios of TMP and TMPi was studied. Compared with TMPi5, the peak potential difference between the oxidation peak and the reduction peak of the LiFePO4|Li half-cell with TMP5 added is reduced, the battery polarization is reduced, the discharge specific capacity after 300 cycles is large, the capacity retention rate is as high as 99.6%, the discharge specific capacity is larger at different current rates, and the electrode resistance is smaller. TMPi5 causes the discharge-specific capacity to attenuate, which is more obvious at high current rates. LiFePO4|Li half-cells with 5% volume ratio of flame retardant have the best electrochemical performance. Finally, the influence mechanism of the phosphorus valence state on battery safety and electrochemical performance was compared and studied. After 300 cycles, the surface of the LiFePO4 electrode with 5% TMP added had a smoother and more uniform CEI film and higher phosphorus (P) and fluorine (F) content, which was beneficial to the improvement of electrochemical performance. The cross-section of the LiFePO4 electrode showed slight collapse and cracks, which slowed down the attenuation of battery capacity. Full article
(This article belongs to the Section Chemical Processes and Systems)
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23 pages, 2707 KiB  
Article
Performance Analysis of Battery State Prediction Based on Improved Transformer and Time Delay Second Estimation Algorithm
by Bo Gao, Xiangjun Li, Fang Guo and Xiping Wang
Batteries 2025, 11(7), 262; https://doi.org/10.3390/batteries11070262 - 13 Jul 2025
Viewed by 412
Abstract
As energy storage technology advances rapidly, the power industry demands accurate state estimation of lithium batteries in energy storage power stations. This study aimed to improve such estimations. An improved Transformer structure was employed to estimate the battery’s state of charge (SOC). The [...] Read more.
As energy storage technology advances rapidly, the power industry demands accurate state estimation of lithium batteries in energy storage power stations. This study aimed to improve such estimations. An improved Transformer structure was employed to estimate the battery’s state of charge (SOC). The Time Delay Second Estimation (TDSE) algorithm optimized the improved Transformer model to overcome traditional models’ limitations in extracting long-term dependency. Innovative particle filter algorithms were proposed to handle the nonlinearity, uncertainty, and dynamic changes in predicting remaining battery life. Results showed that for LiNiMnCoO2 positive electrode datasets, the model’s max SOC estimation error was 2.68% at 10 °C and 2.15% at 30 °C. For LiFePO4 positive electrode datasets, the max error was 2.79% at 10 °C (average 1.25%) and 2.35% at 30 °C (average 0.94%). In full lifecycle calculations, the particle filter algorithm predicted battery capacity with 98.34% accuracy and an RMSE of 0.82%. In conclusion, the improved Transformer and TDSE algorithm enable advanced battery state prediction, and the particle filter algorithm effectively predicts remaining battery life, enhancing the adaptability and robustness of lithium battery state analysis and offering technical support for energy storage station management. Full article
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17 pages, 2734 KiB  
Article
Fabrication and Performance Study of 3D-Printed Ceramic-in-Gel Polymer Electrolytes
by Xiubing Yao, Wendong Qin, Qiankun Hun, Naiyao Mao, Junming Li, Xinghua Liang, Ying Long and Yifeng Guo
Gels 2025, 11(7), 534; https://doi.org/10.3390/gels11070534 - 10 Jul 2025
Viewed by 249
Abstract
Solid-state electrolytes (SSEs) have emerged as a promising solution for next-generation lithium-ion batteries due to their excellent safety and high energy density. However, their practical application is still hindered by critical challenges such as their low ionic conductivity and high interfacial resistance at [...] Read more.
Solid-state electrolytes (SSEs) have emerged as a promising solution for next-generation lithium-ion batteries due to their excellent safety and high energy density. However, their practical application is still hindered by critical challenges such as their low ionic conductivity and high interfacial resistance at room temperature. The innovative application of 3D printing in the field of electrochemistry, particularly in solid-state electrolytes, endows energy storage devices with attractive characteristics. In this study, ceramic-in-gel polymer electrolytes (GPEs) based on PVDF-HFP/PAN@LLZTO were fabricated using a direct ink writing (DIW) 3D printing technique. Under the optimal printing conditions (printing speed of 40 mm/s and fill density of 70%), the printed electrolyte exhibited a uniform and dense sponge-like porous structure, achieving a high ionic conductivity of 5.77 × 10−4 S·cm−1, which effectively facilitated lithium-ion transport. A structural analysis indicated that the LLZTO fillers were uniformly dispersed within the polymer matrix, significantly enhancing the electrochemical stability of the electrolyte. When applied in a LiFePO4|GPEs|Li cell configuration, the electrolyte delivered excellent electrochemical performance, with high initial discharge capacities of 168 mAh·g−1 at 0.1 C and 166 mAh·g−1 at 0.2 C, and retained 92.8% of its capacity after 100 cycles at 0.2 C. This work demonstrates the great potential of 3D printing technology in fabricating high-performance GPEs. It provides a novel strategy for the structural design and industrial scalability of lithium-ion batteries. Full article
(This article belongs to the Special Issue Research Progress and Application Prospects of Gel Electrolytes)
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15 pages, 3755 KiB  
Article
Zero Emissions Analysis for a Hybrid System with Photovoltaic and Thermal Energy in the Balearic Islands University
by Pere Antoni Bibiloni-Mulet, Andreu Moià-Pol, Jacinto Vidal-Noguera, Iván Alonso, Víctor Martínez-Moll, Yamile Díaz Torres, Vicent Canals, Benito Mas and Carles Mulet-Forteza
Solar 2025, 5(3), 31; https://doi.org/10.3390/solar5030031 - 4 Jul 2025
Viewed by 296
Abstract
The University of the Balearic Islands is undertaking a significant energy transition toward a zero-emissions model, motivated by escalating energy costs and strong institutional commitments to climate neutrality. This study investigates the technical and operational feasibility of deploying 7.1 MWp of photovoltaic capacity [...] Read more.
The University of the Balearic Islands is undertaking a significant energy transition toward a zero-emissions model, motivated by escalating energy costs and strong institutional commitments to climate neutrality. This study investigates the technical and operational feasibility of deploying 7.1 MWp of photovoltaic capacity across the campus, integrated with Li-FePO4 battery systems and thermal energy storage. Through a detailed analysis of hourly energy demand, PV generation profiles, and storage constraints, the research evaluates how these technologies can be optimized to meet campus needs. A linear optimization model is applied to assess system performance under the constraint of a 3 MW grid export limit. Furthermore, the potential of demand-side electrification, implemented via a centralized HVAC plant and a 4th–5th generation district heating and cooling network, is analyzed in terms of its ability to maximize on-site PV self-consumption and reduce reliance on grid electricity during non-generation periods. Full article
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13 pages, 1661 KiB  
Article
Optimization of the Inorganic Salts in Coenzyme Q10 Fermentation Medium of Rhodobacter sphaeroides Based on Uniform Design and Artificial Neural Network and Genetic Algorithm
by Yi Zheng, Yujun Xiao, Shuling Tang, Junpeng Li, Yingzi Wu and Yong Zhou
Fermentation 2025, 11(7), 383; https://doi.org/10.3390/fermentation11070383 - 2 Jul 2025
Viewed by 574
Abstract
Coenzyme Q10 (CoQ10) has attracted widespread attention in recent years due to its momentous physiological functions. Microbial fermentation is the major method in CoQ10 industrial production, and Rhodobacter sphaeroides is the main strain for the production of CoQ10 [...] Read more.
Coenzyme Q10 (CoQ10) has attracted widespread attention in recent years due to its momentous physiological functions. Microbial fermentation is the major method in CoQ10 industrial production, and Rhodobacter sphaeroides is the main strain for the production of CoQ10 by fermentation. Optimization of the culture medium is a popular solution to improve the metabolite production. Culture medium is the material basis for microbial growth and product synthesis, of which inorganic salts are a key ingredient. Uniform design (UD), artificial neural network (ANN), and genetic algorithm (GA) are the main research methods. Through uniform design (UD) and artificial neural network/genetic algorithm (ANN-GA) progressive optimization, an optimal formulation of the inorganic salts in fermentation medium was obtained (g·L−1): MgSO4 12, NaCl 2.5, FeSO4 1.6, KH2PO4 0.8, MnSO4 0.1, CaCl2 0.1. Ultimately, the fermentation yield of CoQ10 could reach 255.36 mg·L−1. ANN-GA exhibited a superior prediction capability compared to UD. Compared to UD, the optimization results of ANN-GA had a smaller relative error (ANN-GA 1.23%; UD 3.01%) and a higher increase rate in the fermentation level of CoQ10 (ANN-GA 4.1%; UD 2.04%). R. sphaeroides had a high demand for Mg2+. Full article
(This article belongs to the Section Industrial Fermentation)
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14 pages, 1552 KiB  
Article
Effect of Oxidative Roasting on Selective Leaching of Lithium from Industrially Shredded Lithium Iron Phosphate Blackmass
by Ayesha Tasawar, Daniel Dotto Munchen, Alexander Birich, Rungsima Yeetsorn and Bernd Friedrich
Metals 2025, 15(7), 739; https://doi.org/10.3390/met15070739 - 30 Jun 2025
Viewed by 337
Abstract
The increasing need-based demand for lithium iron phosphate (LFP) batteries in electric vehicles and energy storage systems necessitates the development of efficient and sustainable recycling methods. This study investigates the effect of oxidative roasting on lithium extraction from industrially sourced LiFePO4 (LFP) [...] Read more.
The increasing need-based demand for lithium iron phosphate (LFP) batteries in electric vehicles and energy storage systems necessitates the development of efficient and sustainable recycling methods. This study investigates the effect of oxidative roasting on lithium extraction from industrially sourced LiFePO4 (LFP) blackmass containing high graphite content (~46%) and mixed electrode materials. Roasting at 650 °C for one hour converted LiFePO4 into water-soluble Li3Fe2(PO4)3 and Fe2O3, while reducing carbon and fluorine levels. However, contrary to expectations, mild-acid leaching (pH 2, 40 g/L, 20 °C) of roasted blackmass did not improve lithium recovery compared to unroasted material, yielding approximately 33% extraction efficiency. Strong-acid leaching (pH 0, H2SO4/H2O2) achieved over 95% lithium recovery but also resulted in significant co-dissolution of iron and other impurities. Our XRD and SEM analyses showed that some lithium-containing phases remained in the residue after water leaching, while acid leaching left mainly iron oxide and graphite. These results suggest that, for complex and graphite-rich industrial blackmass, roasting may not always deliver the expected boost in lithium recovery. Our findings highlight the need to tailor recycling processes to the specific characteristics of battery waste and suggest that direct hydrometallurgical methods could be more effective for complex, impurity-rich LFP blackmass streams. Full article
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35 pages, 14682 KiB  
Article
Fast-Balancing Passive Battery Management System with Remote Monitoring for the Automotive Industry
by Ionuț-Constantin Guran, Adriana Florescu, Nicu Bizon and Lucian Andrei Perișoară
Electronics 2025, 14(13), 2606; https://doi.org/10.3390/electronics14132606 - 27 Jun 2025
Viewed by 323
Abstract
Batteries have become the main power source in today’s automotive systems. This paper proposes the design of a fast-balancing passive battery management system (BMS) with remote monitoring for the automotive domain. This system is designed for four series-connected lithium iron phosphate (LiFePO4) cells, [...] Read more.
Batteries have become the main power source in today’s automotive systems. This paper proposes the design of a fast-balancing passive battery management system (BMS) with remote monitoring for the automotive domain. This system is designed for four series-connected lithium iron phosphate (LiFePO4) cells, which are the preferred choice in the automotive industry. The results show that the proposed BMS can monitor the cell voltages with an error lower than 0.12%, and it can perform the balancing operation successfully with maximum currents of 750 mA during both charging and discharging cycles, not only for LiFePO4 cells, but also for lithium-ion (Li-ion) cells. Furthermore, the cell voltages are sent over the controller area network (CAN) interface for remote monitoring. Full article
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21 pages, 3199 KiB  
Article
Sustainable Hydrochar from Orange Peel and Bagasse: A Wet Pyrolysis Approach for Efficient Fe2+ and Mn2+ Removal from Water Using a Factorial Design
by Karina Sampaio da Silva, Marcela de Oliveira Brahim Cortez, Luísa Faria Monteiro Mazzini, Ueslei G. Favero, Leonarde do Nascimento Rodrigues, Renê Chagas da Silva, Maria C. Hespanhol and Renata Pereira Lopes Moreira
Processes 2025, 13(7), 2040; https://doi.org/10.3390/pr13072040 - 27 Jun 2025
Viewed by 388
Abstract
Water pollution is a global concern, especially due to iron and manganese, which, at high concentrations, affect water quality by altering taste, odor, and color. This work explores the sustainable synthesis of hydrochar from orange peel and bagasse using hydrothermal carbonization (HTC) and [...] Read more.
Water pollution is a global concern, especially due to iron and manganese, which, at high concentrations, affect water quality by altering taste, odor, and color. This work explores the sustainable synthesis of hydrochar from orange peel and bagasse using hydrothermal carbonization (HTC) and a 23 factorial design to optimize Fe2+ and Mn2+ removal for water treatment polishing. HTC was performed by varying (1) temperature (100–200 °C), (2) residence time (8–14 h), and (3) activation agent (H3PO4 or NaOH), with a central point at 150 °C for 11 h without activation. Characterization was performed using FTIR, TGA, SEM, nitrogen adsorption (BET) for surface area determination, elemental analysis, Brønsted acidity measurements, and zeta potential analysis. The hydrochar synthesized at 100 °C for 14 h with NaOH (HC6) showed the best Fe2+ and Mn2+ removal performance. The equilibrium time was 400 min, with pseudo-first-order kinetics best fitting the Fe2+ adsorption data, while pseudo-second-order kinetics provided the best fit for Mn2+ adsorption. The adsorption process was best described by the Freundlich and Langmuir isotherms, with maximum adsorption capacities (qmax) of 21.44 and 33.67 mg g−1 for Fe2+ and Mn2+, respectively. It can be concluded that HTC-derived hydrochars offer a sustainable and efficient solution for Fe2+ and Mn2+ removal. This strategy presents a potentially valuable approach for sustainable water treatment, offering advantages for industrial application by operating at lower temperatures and eliminating the need for biomass drying, thereby reducing energy consumption and environmental impact. Full article
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15 pages, 1787 KiB  
Article
Probing Solid-State Interface Kinetics via Alternating Current Electrophoretic Deposition: LiFePO4 Li-Metal Batteries
by Su Jeong Lee and Byoungnam Park
Appl. Sci. 2025, 15(13), 7120; https://doi.org/10.3390/app15137120 - 24 Jun 2025
Viewed by 319
Abstract
This work presents a comprehensive investigation into the interfacial charge storage mechanisms and lithium-ion transport behavior of Li-metal all-solid-state batteries (ASSBs) employing LiFePO4 (LFP) cathodes fabricated via alternating current electrophoretic deposition (AC-EPD) and Li1.3Al0.3Ti1.7(PO4) [...] Read more.
This work presents a comprehensive investigation into the interfacial charge storage mechanisms and lithium-ion transport behavior of Li-metal all-solid-state batteries (ASSBs) employing LiFePO4 (LFP) cathodes fabricated via alternating current electrophoretic deposition (AC-EPD) and Li1.3Al0.3Ti1.7(PO4)3 (LATP) as the solid-state electrolyte. We demonstrate that optimal sintering improves the LATP–LFP interfacial contact, leading to higher lithium diffusivity (~10−9 cm2∙s−1) and diffusion-controlled kinetics (b ≈ 0.5), which directly translate to better rate capability. Structural and electrochemical analyses—including X-ray diffraction, scanning electron microscopy, cyclic voltammetry, and rate capability tests—demonstrate that the cell with LATP sintered at 900 °C delivers the highest Li-ion diffusivity (~10−9 cm2∙s−1), near-ideal diffusion-controlled behavior (b-values ~0.5), and superior rate capability. In contrast, excessive sintering at 1000 °C led to reduced diffusivity (~10−10 cm2∙s−1). The liquid electrolyte system showed higher b-values (~0.58), indicating the inclusion of surface capacitive behavior. The correlation between b-values, diffusivity, and morphology underscores the critical role of interface engineering and electrolyte processing in determining the performance of solid-state batteries. This study establishes AC-EPD as a viable and scalable method for fabricating additive-free LFP cathodes and offers new insights into the structure–property relationships governing the interfacial transport in ASSBs. Full article
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15 pages, 4154 KiB  
Article
Femtosecond Laser-Modulated Oxygen Vacancies in LiFePO4 Thick Electrodes for Rapid Ion Transport
by Xiaowei Han, Lu Chen, Hongshui Wang, Ban Chen, Tai Yang, Donghui Wang and Chunyong Liang
Coatings 2025, 15(7), 738; https://doi.org/10.3390/coatings15070738 - 20 Jun 2025
Viewed by 417
Abstract
Although thick electrodes hold significant potential for enhancing battery energy density, their practical application is limited by restricted ion transport kinetics. Constructing porous structures within thick electrodes is a widely adopted strategy to address this limitation, but it often compromises mass retention and [...] Read more.
Although thick electrodes hold significant potential for enhancing battery energy density, their practical application is limited by restricted ion transport kinetics. Constructing porous structures within thick electrodes is a widely adopted strategy to address this limitation, but it often compromises mass retention and mechanical integrity. In this study, a microchannel structure that balances the electrochemical and mechanical properties of the electrode was identified through simulation and precisely fabricated using femtosecond laser technology. Furthermore, the ultra-short pulse duration and high pulse energy of femtosecond lasers introduce oxygen vacancies into the electrode material, thereby enhancing its electrical conductivity. The obtained electrode exhibited excellent electrochemical performance under high-rate charging and discharging conditions, achieving significantly enhanced cycling stability and capacity retention, with a capacity 1.99 times greater than that of the unstructured electrode after 100 cycles. Meanwhile, the mechanical stability of the laser-processed electrode was maintained. This study provides new insights into the structural design and processing of the thick electrode and contributes to advancements in the field of energy storage. Full article
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