In many electrochemical processes, the transport of charged species is governed by the Nernst-Planck equation, which includes terms for both diffusion and electrochemical migration. In this work, a multi-physics, multi-species model based on the smoothed particle hydrodynamics (SPH) method is presented to model the Nernst-Planck equation in systems with electrodeposition. Electrodeposition occurs when ions are deposited onto an electrode. These deposits create complex boundary geometries, which can be challenging for numerical methods to resolve. SPH is a particularly effective numerical method for systems with moving and deforming boundaries due to its particle nature. This paper discusses the SPH implementation of the Nernst-Planck equations with electrodeposition and verifies the model with an analytical solution and a numerical integrator. A convergence study of migration and precipitation is presented to illustrate the model’s accuracy, along with comparisons of the deposition growth front to experimental results.
{"title":"Smoothed particle hydrodynamics modeling of electrodeposition and dendritic growth under migration- and diffusion-controlled mass transport","authors":"Andrew Cannon, J. McDaniel, E. Ryan","doi":"10.1115/1.4056327","DOIUrl":"https://doi.org/10.1115/1.4056327","url":null,"abstract":"\u0000 In many electrochemical processes, the transport of charged species is governed by the Nernst-Planck equation, which includes terms for both diffusion and electrochemical migration. In this work, a multi-physics, multi-species model based on the smoothed particle hydrodynamics (SPH) method is presented to model the Nernst-Planck equation in systems with electrodeposition. Electrodeposition occurs when ions are deposited onto an electrode. These deposits create complex boundary geometries, which can be challenging for numerical methods to resolve. SPH is a particularly effective numerical method for systems with moving and deforming boundaries due to its particle nature. This paper discusses the SPH implementation of the Nernst-Planck equations with electrodeposition and verifies the model with an analytical solution and a numerical integrator. A convergence study of migration and precipitation is presented to illustrate the model’s accuracy, along with comparisons of the deposition growth front to experimental results.","PeriodicalId":15579,"journal":{"name":"Journal of Electrochemical Energy Conversion and Storage","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2022-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43630681","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Overdischarge is one of the main factors of lithium-ion battery failure, due to the inconsistency of lithium-ion battery in pack. However, the failure mechanism remains unclear. This paper introduces the X-ray computed tomography to explore the gas production and copper dissolution of lithium battery during overdischarge state. From tomographic images in two different cross-section directions, the internal structure changes of bulge deformation and copper deposition are observed to quantitatively analyze the relationship between copper deposition and overdischarge state of charge. The position distribution is analyzed by density distribution feature, which indicate that the gas production is mainly distribute in the middle of the battery, and the copper deposition is distribute around the outer side. The experimental result shows that X-ray CT is a nondestructive, quantitative, visual and effective way to study the internal structure and material distribution of the over-discharge battery. So as to effectively monitor the state of the lithium-ion battery, to avoid dangerous problems such as internal short circuits and thermal runaway.
{"title":"Research on overdischarge lithium-ion battery based on X-ray computed tomography","authors":"Xiaofan Zhang, Lifu Li, Shengqiang Li","doi":"10.1115/1.4056271","DOIUrl":"https://doi.org/10.1115/1.4056271","url":null,"abstract":"\u0000 Overdischarge is one of the main factors of lithium-ion battery failure, due to the inconsistency of lithium-ion battery in pack. However, the failure mechanism remains unclear. This paper introduces the X-ray computed tomography to explore the gas production and copper dissolution of lithium battery during overdischarge state. From tomographic images in two different cross-section directions, the internal structure changes of bulge deformation and copper deposition are observed to quantitatively analyze the relationship between copper deposition and overdischarge state of charge. The position distribution is analyzed by density distribution feature, which indicate that the gas production is mainly distribute in the middle of the battery, and the copper deposition is distribute around the outer side. The experimental result shows that X-ray CT is a nondestructive, quantitative, visual and effective way to study the internal structure and material distribution of the over-discharge battery. So as to effectively monitor the state of the lithium-ion battery, to avoid dangerous problems such as internal short circuits and thermal runaway.","PeriodicalId":15579,"journal":{"name":"Journal of Electrochemical Energy Conversion and Storage","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2022-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45623055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nathan Metzger, I. Vlassiouk, S. Smirnov, Gabriel Mariscal, Ryan Spragg, Xianglin Li
The two main technical limitations of direct methanol fuel cells (DMFCs) are the slow kinetic reactions of the methanol oxidation reaction (MOR) in the anode and the crossing over of unreacted methanol through the proton exchange membrane (PEM). It is common practice to use Nafion membranes as PEMs, which have high ion exchange capacity. However, Nafion-based membranes also have high fuel permeability, decreasing fuel utilization and reducing the potential power density. This manuscript focuses on using graphene-coated (Gr-coated) PEMs to reduce fuel crossover. Protons can permeate across graphene and thus it can be employed in various devices as a proton conductive membrane. Here we report efficiency of Gr-coated Nafions. We tested performance and crossover at three different temperatures with four different fuel concentrations and compared to a Nafion PEM that underwent that same test conditions. We found that the adhesion of Gr on to PEMs is not sufficient for prolong fuel cell operation resulting in Gr delamination at high temperatures leading to a higher fuel crossover values compared to lower temperature testing. The results for 7.5M methanol fuel show a reduction of up to 25% in methanol crossover, translating to a peak power density that increases from 3.9 to 9.5 mW/cm2 when using a Gr-Coated PEM compared to a Nafion PEM at 30°C.
{"title":"Experimental Studies of Graphene-Coated Polymer Electrolyte Membranes for Direct Methanol Fuel Cells","authors":"Nathan Metzger, I. Vlassiouk, S. Smirnov, Gabriel Mariscal, Ryan Spragg, Xianglin Li","doi":"10.1115/1.4056269","DOIUrl":"https://doi.org/10.1115/1.4056269","url":null,"abstract":"The two main technical limitations of direct methanol fuel cells (DMFCs) are the slow kinetic reactions of the methanol oxidation reaction (MOR) in the anode and the crossing over of unreacted methanol through the proton exchange membrane (PEM). It is common practice to use Nafion membranes as PEMs, which have high ion exchange capacity. However, Nafion-based membranes also have high fuel permeability, decreasing fuel utilization and reducing the potential power density. This manuscript focuses on using graphene-coated (Gr-coated) PEMs to reduce fuel crossover. Protons can permeate across graphene and thus it can be employed in various devices as a proton conductive membrane. Here we report efficiency of Gr-coated Nafions. We tested performance and crossover at three different temperatures with four different fuel concentrations and compared to a Nafion PEM that underwent that same test conditions. We found that the adhesion of Gr on to PEMs is not sufficient for prolong fuel cell operation resulting in Gr delamination at high temperatures leading to a higher fuel crossover values compared to lower temperature testing. The results for 7.5M methanol fuel show a reduction of up to 25% in methanol crossover, translating to a peak power density that increases from 3.9 to 9.5 mW/cm2 when using a Gr-Coated PEM compared to a Nafion PEM at 30°C.","PeriodicalId":15579,"journal":{"name":"Journal of Electrochemical Energy Conversion and Storage","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2022-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46417232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dongxiao Yang, Xiaodong Zhang, Yaguang Liu, Shili Song
Reverse electrodialysis - Multi-effect distillation(RED-MED) heat engine has received increasing attention in recent years, due to its ability of converting low temperature waste heat into salinity gradient energy, and then extracting electric power from it. In this work, the RED-MED coupled system was studied with a mathematical model, which was validated by our experimental results. The influences of RED channel length and the feed flow rate on the performance of the coupled system were studied. Furthermore, in the literature, only one of the two streams leaving RED, i.e. either the dilute or the concentrate, is split and partly mixed with another stream before being treated in MED. In this paper, a modified scheme is proposed, in which both the two streams were split, i.e. only a fraction of the concentrate solution was mixed with a fraction of the dilute. The purpose of the modification is to further reduce the total flow rate in MED. After the modification, both the energy efficiency and the heat exchange area requirement of MED increase. The optimum value of the split fraction was discussed. Results imply that while the studies reported in the literature mainly focus on the aspects closely related to the RED section, attention should also be paid to the overall scheme design of the RED-MED coupled system.
{"title":"A Modeling Study of RED-MED Salinity Gradient Heat Engine: the Conventional Scheme and A Modified Scheme","authors":"Dongxiao Yang, Xiaodong Zhang, Yaguang Liu, Shili Song","doi":"10.1115/1.4056270","DOIUrl":"https://doi.org/10.1115/1.4056270","url":null,"abstract":"\u0000 Reverse electrodialysis - Multi-effect distillation(RED-MED) heat engine has received increasing attention in recent years, due to its ability of converting low temperature waste heat into salinity gradient energy, and then extracting electric power from it. In this work, the RED-MED coupled system was studied with a mathematical model, which was validated by our experimental results. The influences of RED channel length and the feed flow rate on the performance of the coupled system were studied. Furthermore, in the literature, only one of the two streams leaving RED, i.e. either the dilute or the concentrate, is split and partly mixed with another stream before being treated in MED. In this paper, a modified scheme is proposed, in which both the two streams were split, i.e. only a fraction of the concentrate solution was mixed with a fraction of the dilute. The purpose of the modification is to further reduce the total flow rate in MED. After the modification, both the energy efficiency and the heat exchange area requirement of MED increase. The optimum value of the split fraction was discussed. Results imply that while the studies reported in the literature mainly focus on the aspects closely related to the RED section, attention should also be paid to the overall scheme design of the RED-MED coupled system.","PeriodicalId":15579,"journal":{"name":"Journal of Electrochemical Energy Conversion and Storage","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2022-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45887117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Synthesized biomass-based carbonaceous materials from Palmae plant wastes with self-adhesive properties, converted into coin-like shapes, are used as supercapacitor electrodes with high power and energy density, high specific capacitance, excellent electrical conductivity, low cost, and environmentally friendly. Therefore, this study aims to investigate a simple and cost-effective method to generate porous carbon activation from Palmae plant waste biomass, namely areca leaf midrib (ALM). Activated carbon (AC) material derived from ALM was obtained through pre-carbonization, alkaline chemical activation, and two-step pyrolysis, namely carbonization and physical activation at 600°C and 700°C in the N2 as well as CO2 atmosphere, respectively. Its physical properties show an sp2 structure with high graphitization or amorphousness and two sloping peaks in the hkl plane at an angle of 2θ, approximately 24° and 44°. The electrochemical properties of AC supercapacitor cells derived from ALM biomass have the highest specific capacitance value of 216 Fg−1 at a scan rate of 1 mVs−1 in a two-electrode system. Furthermore, the cell obtained a maximum energy density of 11 Whkg−1 and a power density of 196 W kg−1, respectively. Therefore, this study recommends an innovative and environmentally safe approach for producing high-performance supercapacitor cell electrodes for energy storage without adding nanomaterials and externally doped heteroatoms.
利用棕榈植物废弃物合成具有自粘特性的生物质基碳质材料，转化成硬币状，作为超级电容器电极，具有高功率和能量密度、高比电容、优异的导电性、低成本、环保等特点。因此，本研究旨在探索一种简单而经济的方法，从棕榈植物废弃物生物质，即槟榔叶中脉(ALM)中产生多孔碳活化。通过预炭化、碱性化学活化、两步热解，即在600°C N2和700°C CO2气氛下炭化和物理活化，得到ALM衍生的活性炭(AC)材料。其物理性质表现为高度石墨化或非晶化的sp2结构，在hkl平面上有两个倾角为2θ，约为24°和44°的倾斜峰。在双电极系统中，当扫描速率为1 mv−1时，由ALM生物质制成的交流超级电容器的电化学性能最高，比电容值为216 Fg−1。此外，该电池的最大能量密度为11 Whkg−1，功率密度为196 W kg−1。因此，本研究推荐了一种创新且环保的方法，可以在不添加纳米材料和外部掺杂杂原子的情况下生产用于储能的高性能超级电容器电池电极。
{"title":"The Self Adhesive Properties of Carbon Activated-Like Shape Coin Derived from Palmae Plant Waste and used as High-Performance Supercapacitor Electrodes","authors":"R. Farma, Bela Winalda, I. Apriyani","doi":"10.1115/1.4056268","DOIUrl":"https://doi.org/10.1115/1.4056268","url":null,"abstract":"\u0000 Synthesized biomass-based carbonaceous materials from Palmae plant wastes with self-adhesive properties, converted into coin-like shapes, are used as supercapacitor electrodes with high power and energy density, high specific capacitance, excellent electrical conductivity, low cost, and environmentally friendly. Therefore, this study aims to investigate a simple and cost-effective method to generate porous carbon activation from Palmae plant waste biomass, namely areca leaf midrib (ALM). Activated carbon (AC) material derived from ALM was obtained through pre-carbonization, alkaline chemical activation, and two-step pyrolysis, namely carbonization and physical activation at 600°C and 700°C in the N2 as well as CO2 atmosphere, respectively. Its physical properties show an sp2 structure with high graphitization or amorphousness and two sloping peaks in the hkl plane at an angle of 2θ, approximately 24° and 44°. The electrochemical properties of AC supercapacitor cells derived from ALM biomass have the highest specific capacitance value of 216 Fg−1 at a scan rate of 1 mVs−1 in a two-electrode system. Furthermore, the cell obtained a maximum energy density of 11 Whkg−1 and a power density of 196 W kg−1, respectively. Therefore, this study recommends an innovative and environmentally safe approach for producing high-performance supercapacitor cell electrodes for energy storage without adding nanomaterials and externally doped heteroatoms.","PeriodicalId":15579,"journal":{"name":"Journal of Electrochemical Energy Conversion and Storage","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2022-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45093270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lead-acid batteries have the advantages of wide temperature adaptability, large discharge power, and high safety factor. It is still widely used in electrochemical energy storage systems. In order to ensure the application of batteries under extreme working conditions, it is necessary to explore the degradation mechanism. In this study, the experimental battery is the same type of 2V-500Ah lead-acid battery produced by different manufacturers. Firstly, the three batteries were subjected to the same high temperature and high current cycle thermal shock test (50°C, 0.2C current), combined with quantitative analysis of plate active material and microscopic morphology observation. In addition, numerical studies are used to simulate the distribution of electrical parameters on the positive plate and grid. The above three parts are combined to study the causes of accelerated battery decay under high temperature and high current conditions. The results showed that the extreme conditions aggravated the non-uniformity of the potential distribution of the positive plate and the grid, which increased by 10.62% and 51.59%, respectively. The battery with higher remaining capacity has more a-PbO2 in the active material, and has a considerable amount of β-PbO2. The battery with the smallest remaining capacity has the largest volume of active material. The volume of the material affects the electrochemical reaction surface area. The larger the volume of the material, the higher the resistance of that part, which will lead to an increase in the overall impedance of the battery.
{"title":"Research on the mechanism of cathode failure of lead-acid battery under extreme conditions","authors":"Yaowei Li, Nawei Lyu, Yang Jin","doi":"10.1115/1.4056207","DOIUrl":"https://doi.org/10.1115/1.4056207","url":null,"abstract":"\u0000 Lead-acid batteries have the advantages of wide temperature adaptability, large discharge power, and high safety factor. It is still widely used in electrochemical energy storage systems. In order to ensure the application of batteries under extreme working conditions, it is necessary to explore the degradation mechanism. In this study, the experimental battery is the same type of 2V-500Ah lead-acid battery produced by different manufacturers. Firstly, the three batteries were subjected to the same high temperature and high current cycle thermal shock test (50°C, 0.2C current), combined with quantitative analysis of plate active material and microscopic morphology observation. In addition, numerical studies are used to simulate the distribution of electrical parameters on the positive plate and grid. The above three parts are combined to study the causes of accelerated battery decay under high temperature and high current conditions. The results showed that the extreme conditions aggravated the non-uniformity of the potential distribution of the positive plate and the grid, which increased by 10.62% and 51.59%, respectively. The battery with higher remaining capacity has more a-PbO2 in the active material, and has a considerable amount of β-PbO2. The battery with the smallest remaining capacity has the largest volume of active material. The volume of the material affects the electrochemical reaction surface area. The larger the volume of the material, the higher the resistance of that part, which will lead to an increase in the overall impedance of the battery.","PeriodicalId":15579,"journal":{"name":"Journal of Electrochemical Energy Conversion and Storage","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2022-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46536396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A new model for simulating battery temperature changes from the lower surface to the upper surface is proposed. The cell model is established with experimental calibration. Simultaneously, the Cell-to-Pack model is established through experimental benchmarking. In addition, the thermal properties of Cell-to-Pack and an ordinary battery pack that has an enclosure on the basis were compared under four different working conditions. The results indicate that adding an enclosure to the Cell-to-Pack has little effect on the thermal performance of the battery pack. Adding an enclosure to the Cell-to-Pack hardly improve the temperature uniformity of the battery under cooling conditions; the temperature difference between the upper and lower surfaces of the batteries at both ends of the module drops by approximately 0.5°C, while the central temperature difference is basically unchanged. Compared with fast charging without cooling, the battery temperature dropped by more than 12°C under the fast charge condition with cooling. More importantly, the specific energy and packaging efficiency of the battery dropped from 160.27Wh·kg−1 and 73.1% to 148.72 Wh·kg−1 and 67.8%, respectively, after the Cell-to-Pack was added with an enclosure.
{"title":"Experimental and Simulations Study of Thermal Performance of Cell-to-Pack Structure for a Li-ion Battery Pack","authors":"Kai Shen, Linsen Yang, Jieyu Sun, Chengshan Xu, Huaibin Wang, Yuejiu Zheng, Xuning Feng","doi":"10.1115/1.4056112","DOIUrl":"https://doi.org/10.1115/1.4056112","url":null,"abstract":"\u0000 A new model for simulating battery temperature changes from the lower surface to the upper surface is proposed. The cell model is established with experimental calibration. Simultaneously, the Cell-to-Pack model is established through experimental benchmarking. In addition, the thermal properties of Cell-to-Pack and an ordinary battery pack that has an enclosure on the basis were compared under four different working conditions. The results indicate that adding an enclosure to the Cell-to-Pack has little effect on the thermal performance of the battery pack. Adding an enclosure to the Cell-to-Pack hardly improve the temperature uniformity of the battery under cooling conditions; the temperature difference between the upper and lower surfaces of the batteries at both ends of the module drops by approximately 0.5°C, while the central temperature difference is basically unchanged. Compared with fast charging without cooling, the battery temperature dropped by more than 12°C under the fast charge condition with cooling. More importantly, the specific energy and packaging efficiency of the battery dropped from 160.27Wh·kg−1 and 73.1% to 148.72 Wh·kg−1 and 67.8%, respectively, after the Cell-to-Pack was added with an enclosure.","PeriodicalId":15579,"journal":{"name":"Journal of Electrochemical Energy Conversion and Storage","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2022-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42964402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Anion exchange membrane fuel cells (AEMFCs) are in development as a low-cost alternative to proton exchange membrane fuel cells (PEMFCs). AEMFCs produce water at the anode side and consume it at the cathode side, resulting in no cathode water-flooding like in PEMFCS. However, it brings complexity to water transportation behaviour and requires appropriate water balance to avoid membrane drying out. In this study, a two-dimensional two-phase multi-physics model has been developed to investigate the impacts of three key electrode parameters (porosity, catalyst loading, and ionomer content) that are responsible for water production and transport as well as the performance of an AEMFC. A piecewise constant function along the x-direction (reactant diffusion direction) is used to apply the gradient on the porosity and platinum loading. The present results show that a larger porosity gradient near the cathode gas-diffusion layer (GDL)/flow-channel interface and lower near the GDL/microporous layer (MPL) interface can enhance mass transport and water removal, which is benefited the AEMFC performance. However, anode GDL porosity gradients show a lower AEMFC performance compared to the cathode porosity gradients. Moreover, it was confirmed that for both electrodes, the performance of AEMFC was significantly dependent on each electrode parameter.
{"title":"Investigation of Gradient Platinum-Loading and Porosity Distribution for Anion Exchange Membrane Fuel Cells","authors":"H. Mousa, L. Xing, P. Das","doi":"10.1115/1.4056029","DOIUrl":"https://doi.org/10.1115/1.4056029","url":null,"abstract":"\u0000 Anion exchange membrane fuel cells (AEMFCs) are in development as a low-cost alternative to proton exchange membrane fuel cells (PEMFCs). AEMFCs produce water at the anode side and consume it at the cathode side, resulting in no cathode water-flooding like in PEMFCS. However, it brings complexity to water transportation behaviour and requires appropriate water balance to avoid membrane drying out. In this study, a two-dimensional two-phase multi-physics model has been developed to investigate the impacts of three key electrode parameters (porosity, catalyst loading, and ionomer content) that are responsible for water production and transport as well as the performance of an AEMFC. A piecewise constant function along the x-direction (reactant diffusion direction) is used to apply the gradient on the porosity and platinum loading. The present results show that a larger porosity gradient near the cathode gas-diffusion layer (GDL)/flow-channel interface and lower near the GDL/microporous layer (MPL) interface can enhance mass transport and water removal, which is benefited the AEMFC performance. However, anode GDL porosity gradients show a lower AEMFC performance compared to the cathode porosity gradients. Moreover, it was confirmed that for both electrodes, the performance of AEMFC was significantly dependent on each electrode parameter.","PeriodicalId":15579,"journal":{"name":"Journal of Electrochemical Energy Conversion and Storage","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2022-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45464533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jianlong Chen, Chenghao Zhang, Cong Chen, Chenlei Lu, Xuan Dongji
State of charge (SOC) of lithium-ion battery is an indispensable performance indicator in battery management system (BMS), which is essential to ensure the safe operation of the battery and avoid potential hazards. However, SOC can't be directly measured by sensors or tools. In order to accurately estimate the SOC, this paper proposes a convolutional neural network based on self-attention mechanism. Firstly, the one-dimensional convolution is introduced to extract features from battery voltage, current, and temperature data. Then the self-attention mechanism can reduce the dependence on external information and well capture the internal correlation of features extracted by the convolutional layer. Finally, the proposed method is validated on four dynamic driving conditions at five temperatures and compared with other two deep learning methods. The experimental results show that the proposed method has good accuracy and robustness.
{"title":"State-of-charge estimation of lithium-ion batteries using convolutional neural network with self-attention mechanism","authors":"Jianlong Chen, Chenghao Zhang, Cong Chen, Chenlei Lu, Xuan Dongji","doi":"10.1115/1.4055985","DOIUrl":"https://doi.org/10.1115/1.4055985","url":null,"abstract":"\u0000 State of charge (SOC) of lithium-ion battery is an indispensable performance indicator in battery management system (BMS), which is essential to ensure the safe operation of the battery and avoid potential hazards. However, SOC can't be directly measured by sensors or tools. In order to accurately estimate the SOC, this paper proposes a convolutional neural network based on self-attention mechanism. Firstly, the one-dimensional convolution is introduced to extract features from battery voltage, current, and temperature data. Then the self-attention mechanism can reduce the dependence on external information and well capture the internal correlation of features extracted by the convolutional layer. Finally, the proposed method is validated on four dynamic driving conditions at five temperatures and compared with other two deep learning methods. The experimental results show that the proposed method has good accuracy and robustness.","PeriodicalId":15579,"journal":{"name":"Journal of Electrochemical Energy Conversion and Storage","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2022-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47538572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
For the problem of performance gap between individual cells in retired lithium batteries after group use, which affects the usable capacity of battery pack, a grouping bi-directional equalization method based on variable domain fuzzy control is proposed. Equalization circuits based on single inductor and LC oscillation circuit are respectively used for inter-cell and inter-cell group, to achieve inter-cell equalization and inter-cell group equalization; Variable domain fuzzy control strategy is used to determine the reasonable range of operating current according to State of Health (SOH) of the battery, combined with the relationship between the capacity decay coefficient and the average operational range of State of Charge (SOC); the equalization current is dynamically adjusted according to its mathematical relationship with operating current. To verify the effectiveness of this equalization method, an experimental platform was built and verification simulations were performed. The result of experiments shows, the equalization speed is increased by 25%, comparing to fixed equalization current control strategy; the capacity decay is reduced by 6% and the service life is extended after experiments of 1200 charge-discharge cycles, comparing to traditional fuzzy equalization strategy.
{"title":"Balancing method of retired battery pack based on variable domain fuzzy control","authors":"Tiezhou Wu, Liuliang Chen, Yuhong Xu, Xiaoxing Zhang","doi":"10.1115/1.4055880","DOIUrl":"https://doi.org/10.1115/1.4055880","url":null,"abstract":"\u0000 For the problem of performance gap between individual cells in retired lithium batteries after group use, which affects the usable capacity of battery pack, a grouping bi-directional equalization method based on variable domain fuzzy control is proposed. Equalization circuits based on single inductor and LC oscillation circuit are respectively used for inter-cell and inter-cell group, to achieve inter-cell equalization and inter-cell group equalization; Variable domain fuzzy control strategy is used to determine the reasonable range of operating current according to State of Health (SOH) of the battery, combined with the relationship between the capacity decay coefficient and the average operational range of State of Charge (SOC); the equalization current is dynamically adjusted according to its mathematical relationship with operating current. To verify the effectiveness of this equalization method, an experimental platform was built and verification simulations were performed. The result of experiments shows, the equalization speed is increased by 25%, comparing to fixed equalization current control strategy; the capacity decay is reduced by 6% and the service life is extended after experiments of 1200 charge-discharge cycles, comparing to traditional fuzzy equalization strategy.","PeriodicalId":15579,"journal":{"name":"Journal of Electrochemical Energy Conversion and Storage","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2022-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47799609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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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