Abstract This study proposes a stepped channel liquid-cooled battery thermal management system based on lightweight. The impact of channel width, cell-to-cell lateral spacing, contact height, and contact angle on the effectiveness of the TCS is investigated through using numerical simulation. The weight sensitivity factor is adopted to evaluate the effect of TCS weight (mTCS) on the maximum temperature (Tmax) of battery pack. Results suggest that the channel width plays the most critical role, followed by cell-to-cell lateral spacing and contact angle, while the contact height has minimal influence. Four parameters that affect the thermal balance performance of battery pack, including the number of channels, and baffles, baffle angle, and coolant inlet velocity, are presented using orthogonal experiment. Results indicate that the number of channels and baffle angle have a significant influence on the thermal balance of battery pack, while thermal performance is largely insensitive to coolant inlet velocity and number of baffles. Based on the analysis stated in this work, an improved design of the TCS is presented that reduces weight by 54.08% while increasing Tmax only by 2.52 K.
{"title":"Lithium battery liquid-cooled thermal management system of stepped-channel based on lightweight","authors":"Long Zhou, Shengnan Li, Ankur Jain, Guoqiang Chen, Desui Guo, Jincan Kan, Yong Zhao","doi":"10.1115/1.4063848","DOIUrl":"https://doi.org/10.1115/1.4063848","url":null,"abstract":"Abstract This study proposes a stepped channel liquid-cooled battery thermal management system based on lightweight. The impact of channel width, cell-to-cell lateral spacing, contact height, and contact angle on the effectiveness of the TCS is investigated through using numerical simulation. The weight sensitivity factor is adopted to evaluate the effect of TCS weight (mTCS) on the maximum temperature (Tmax) of battery pack. Results suggest that the channel width plays the most critical role, followed by cell-to-cell lateral spacing and contact angle, while the contact height has minimal influence. Four parameters that affect the thermal balance performance of battery pack, including the number of channels, and baffles, baffle angle, and coolant inlet velocity, are presented using orthogonal experiment. Results indicate that the number of channels and baffle angle have a significant influence on the thermal balance of battery pack, while thermal performance is largely insensitive to coolant inlet velocity and number of baffles. Based on the analysis stated in this work, an improved design of the TCS is presented that reduces weight by 54.08% while increasing Tmax only by 2.52 K.","PeriodicalId":15579,"journal":{"name":"Journal of Electrochemical Energy Conversion and Storage","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135570124","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}
Xiaoyu Liu, Lang Chen, Lijun Zhu, Jian Wang, Long Chen, Xiankai Zeng, Ziang Song, Lujun Wang
Abstract Battery state of charge (SOC) estimation is one of the main functions of the battery management system in electric vehicles. If the actual SOC of the battery differs significantly from the estimated value, it can lead to improper battery usage, resulting in unexpected rapid voltage drops or increases, which can affect driving safety. Therefore, high-accuracy SOC estimation is of great importance for battery management and usage. Currently used SOC estimation methods suffer from issues such as strong dependence on model parameters, error propagation from measurements, and sensitivity to initial values. In this study, we propose a high-precision SOC estimation strategy based on deep belief network (DBN) feature extraction and extended Kalman filter (EKF) for smooth output. The proposed strategy has been rigorously tested under different temperature conditions using the dynamic stress test (DST) and urban dynamometer driving schedule (US06) driving cycles. The mean absolute error (MAE) and root-mean-square error (RMSE) of the proposed strategy are controlled within 1.1% and 1.2%, respectively. This demonstrates the high-precision estimation achieved. To further validate the generality of this strategy, we also apply it to graphene batteries and conduct tests under US06 and highway fuel economy test (HWFET) driving cycles at temperatures of 25 °C and −10 °C. The test results show MAE of 0.47% and 2.01%, respectively.
{"title":"High-Accuracy Battery SOC Estimation Strategy Based on Deep Belief Network Cascaded with Extended Kalman Filter","authors":"Xiaoyu Liu, Lang Chen, Lijun Zhu, Jian Wang, Long Chen, Xiankai Zeng, Ziang Song, Lujun Wang","doi":"10.1115/1.4063431","DOIUrl":"https://doi.org/10.1115/1.4063431","url":null,"abstract":"Abstract Battery state of charge (SOC) estimation is one of the main functions of the battery management system in electric vehicles. If the actual SOC of the battery differs significantly from the estimated value, it can lead to improper battery usage, resulting in unexpected rapid voltage drops or increases, which can affect driving safety. Therefore, high-accuracy SOC estimation is of great importance for battery management and usage. Currently used SOC estimation methods suffer from issues such as strong dependence on model parameters, error propagation from measurements, and sensitivity to initial values. In this study, we propose a high-precision SOC estimation strategy based on deep belief network (DBN) feature extraction and extended Kalman filter (EKF) for smooth output. The proposed strategy has been rigorously tested under different temperature conditions using the dynamic stress test (DST) and urban dynamometer driving schedule (US06) driving cycles. The mean absolute error (MAE) and root-mean-square error (RMSE) of the proposed strategy are controlled within 1.1% and 1.2%, respectively. This demonstrates the high-precision estimation achieved. To further validate the generality of this strategy, we also apply it to graphene batteries and conduct tests under US06 and highway fuel economy test (HWFET) driving cycles at temperatures of 25 °C and −10 °C. The test results show MAE of 0.47% and 2.01%, respectively.","PeriodicalId":15579,"journal":{"name":"Journal of Electrochemical Energy Conversion and Storage","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135804889","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}
Abstract In this study, triphenylphosphine boron trifluoride (BF3 · PPh3) was synthesized to be used as an electrolyte additive in Li/LiCoO2 half-cells. Fourier-transform infrared spectroscopy, X-ray diffraction, nuclear magnetic resonance, and X-ray photoelectron spectroscopy analysis techniques were used to determine the structure and composition of the synthesized substance. The battery performance was investigated by adding certain amounts of BF3 · PPh3 in 1 M LiPF6-ethylene carbonate/dimethyl carbonate/diethyl carbonate (1:1:1 by volume) electrolyte. CR2032 coin cells were assembled with the electrodes and electrolytes prepared in the laboratory. The electrochemical behaviors of the battery were investigated via cyclic voltammetry and charge–discharge tests. The addition of 0.5 wt% and 1 wt% BF3 · PPh3 in the electrolyte improved the lithium-ion battery’s ionic conductivity and capacity retention. The results show that BF3 · PPh3 has potential applications in lithium-ion batteries.
摘要本研究合成了三苯基膦三氟化硼(BF3·PPh3)作为Li/LiCoO2半电池的电解质添加剂。采用傅里叶变换红外光谱、x射线衍射、核磁共振、x射线光电子能谱等分析技术对合成物质的结构和组成进行了测定。在1 M lipf6 -碳酸乙烯/碳酸二甲酯/碳酸二乙酯(体积比1:1:1)电解质中加入一定量的BF3·PPh3，考察电池性能。用实验室制备的电极和电解质组装CR2032硬币电池。通过循环伏安法和充放电试验对电池的电化学行为进行了研究。在电解液中分别添加0.5 wt%和1 wt%的BF3·PPh3，提高了锂离子电池的离子电导率和容量保持率。结果表明，BF3·PPh3在锂离子电池中具有潜在的应用前景。
{"title":"DEVELOPMENT OF BORON CONTAINING ELECTROLYTE ADDITIVE FOR LITHIUM ION BATTERIES","authors":"Zahid Sarigol, Gulay Ozkan, Goksel Ozkan","doi":"10.1115/1.4063429","DOIUrl":"https://doi.org/10.1115/1.4063429","url":null,"abstract":"Abstract In this study, triphenylphosphine boron trifluoride (BF3 · PPh3) was synthesized to be used as an electrolyte additive in Li/LiCoO2 half-cells. Fourier-transform infrared spectroscopy, X-ray diffraction, nuclear magnetic resonance, and X-ray photoelectron spectroscopy analysis techniques were used to determine the structure and composition of the synthesized substance. The battery performance was investigated by adding certain amounts of BF3 · PPh3 in 1 M LiPF6-ethylene carbonate/dimethyl carbonate/diethyl carbonate (1:1:1 by volume) electrolyte. CR2032 coin cells were assembled with the electrodes and electrolytes prepared in the laboratory. The electrochemical behaviors of the battery were investigated via cyclic voltammetry and charge–discharge tests. The addition of 0.5 wt% and 1 wt% BF3 · PPh3 in the electrolyte improved the lithium-ion battery’s ionic conductivity and capacity retention. The results show that BF3 · PPh3 has potential applications in lithium-ion batteries.","PeriodicalId":15579,"journal":{"name":"Journal of Electrochemical Energy Conversion and Storage","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134948046","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}
Abstract Anode materials based on hard carbon are the focus of research in the field of batteries, and bio-hard carbon is one of the most important materials. In this study, we use the invasive species Spartina alterniflora as raw material and doped with nano-graphite to produce high-performance anode materials. It can achieve a first coulomb efficiency of 67%, which is nearly 10% higher than Spartina alterniflora without nano-graphite doped. The specific capacity is close to 300 mA h g−1 under the current of 20 mA g−1. By comparison, we found that the modified Spartina alterniflora has great sodium storage capacity, and the study also proved that Spartina alterniflora material can be modified into a high-performance anode material with high economic value.
摘要基于硬碳负极材料的重点研究领域的电池,和bio-hard碳是最重要的材料之一。本研究以入侵物种互花米草为原料，掺杂纳米石墨制备高性能阳极材料。其第一库仑效率可达67%，比未掺杂纳米石墨的互花米草提高近10%。在20ma g−1电流下，比容量接近300ma h g−1。通过比较，我们发现经改性的互花米草具有很大的储钠能力，研究也证明了互花米草材料可以改性为具有较高经济价值的高性能阳极材料。
{"title":"Nano graphite-doped <i>Spartina alterniflora</i>-based hard carbon as high performance anode for sodium-ion batteries","authors":"Hongkuan Cheng, Qihang Shu, Huanyu Wei, Xingzhang Luo, Suzhen Huang, Zheng Zheng","doi":"10.1115/1.4063397","DOIUrl":"https://doi.org/10.1115/1.4063397","url":null,"abstract":"Abstract Anode materials based on hard carbon are the focus of research in the field of batteries, and bio-hard carbon is one of the most important materials. In this study, we use the invasive species Spartina alterniflora as raw material and doped with nano-graphite to produce high-performance anode materials. It can achieve a first coulomb efficiency of 67%, which is nearly 10% higher than Spartina alterniflora without nano-graphite doped. The specific capacity is close to 300 mA h g−1 under the current of 20 mA g−1. By comparison, we found that the modified Spartina alterniflora has great sodium storage capacity, and the study also proved that Spartina alterniflora material can be modified into a high-performance anode material with high economic value.","PeriodicalId":15579,"journal":{"name":"Journal of Electrochemical Energy Conversion and Storage","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134948216","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}
Jiahao Zhang, Jiadui Chen, Ling He, Dan Liu, Kai Yang, Qinghua Liu
Abstract The estimation of state of charge (SOC) is a critical issue in the energy management of electric vehicle (EV) power batteries. However, the current accuracy of SOC estimation methods does not meet the requirements of practical applications. Therefore, this study proposes an improved lithium-ion battery SOC estimation method that combines deep residual shrinkage network (DRSN) and bidirectional gated recurrent unit (BiGRU) to enhance the SOC estimation accuracy. First, we insert the bidirectional gated recurrent unit neural network between the global average pooling layer and the output fully connected layer of the deep residual shrinkage network. This improvement enhances the model’s expressiveness, robustness, and data learning effect. Second, we develop a new activation function called “∂_swish” to replace the original ReLU activation function in the deep residual shrinkage network. The ∂_swish activation function improves the accuracy of the deep network model and reduces the risk of overfitting by utilizing its regularization effect. Finally, we conduct experimental tests at three different temperatures using the FUDS driving cycle dataset and the DST-US06-FUDS continuous driving cycle dataset. The algorithm model’s convergence speed is verified by comparing it with other models. The results show that compared to other models, the proposed method significantly improves SOC estimation accuracy at three different temperatures. In addition, the method demonstrates a high convergence speed.
{"title":"State of charge estimation of lithium–ion battery based on IDRSN and BiGRU","authors":"Jiahao Zhang, Jiadui Chen, Ling He, Dan Liu, Kai Yang, Qinghua Liu","doi":"10.1115/1.4063173","DOIUrl":"https://doi.org/10.1115/1.4063173","url":null,"abstract":"Abstract The estimation of state of charge (SOC) is a critical issue in the energy management of electric vehicle (EV) power batteries. However, the current accuracy of SOC estimation methods does not meet the requirements of practical applications. Therefore, this study proposes an improved lithium-ion battery SOC estimation method that combines deep residual shrinkage network (DRSN) and bidirectional gated recurrent unit (BiGRU) to enhance the SOC estimation accuracy. First, we insert the bidirectional gated recurrent unit neural network between the global average pooling layer and the output fully connected layer of the deep residual shrinkage network. This improvement enhances the model’s expressiveness, robustness, and data learning effect. Second, we develop a new activation function called “∂_swish” to replace the original ReLU activation function in the deep residual shrinkage network. The ∂_swish activation function improves the accuracy of the deep network model and reduces the risk of overfitting by utilizing its regularization effect. Finally, we conduct experimental tests at three different temperatures using the FUDS driving cycle dataset and the DST-US06-FUDS continuous driving cycle dataset. The algorithm model’s convergence speed is verified by comparing it with other models. The results show that compared to other models, the proposed method significantly improves SOC estimation accuracy at three different temperatures. In addition, the method demonstrates a high convergence speed.","PeriodicalId":15579,"journal":{"name":"Journal of Electrochemical Energy Conversion and Storage","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134948204","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}
Abstract Lithium-ion batteries (LIBs) are widely used in electric vehicles, energy storage power stations and other portable devices for their high energy densities, long cycle life and low self-discharge rate. However, they still face several challenges. Low-temperature environments have slowed down the use of LIBs by significantly deteriorating their normal performance. This review aims to resolve this issue by clarifying the phenomenon and reasons of the deterioration of LIBs performance at low temperatures. From the perspective of system management, this review summarizes and analyzes the common performance-improving methods from two aspects including preheating and charging optimization, then depicts the future development of methods in this regard. This review is expected to inspire further studies for the improvement of the LIB performance at low temperatures.
{"title":"A review on low-temperature performance management of lithium-ion batteries","authors":"Jincheng Zhan, Yifei Deng, Yaohui Gao, Jiaoyi Ren, Yuang Liu, Rao Shun, Weifeng Li, Zhenhai Gao, Yupeng Chen","doi":"10.1115/1.4063611","DOIUrl":"https://doi.org/10.1115/1.4063611","url":null,"abstract":"Abstract Lithium-ion batteries (LIBs) are widely used in electric vehicles, energy storage power stations and other portable devices for their high energy densities, long cycle life and low self-discharge rate. However, they still face several challenges. Low-temperature environments have slowed down the use of LIBs by significantly deteriorating their normal performance. This review aims to resolve this issue by clarifying the phenomenon and reasons of the deterioration of LIBs performance at low temperatures. From the perspective of system management, this review summarizes and analyzes the common performance-improving methods from two aspects including preheating and charging optimization, then depicts the future development of methods in this regard. This review is expected to inspire further studies for the improvement of the LIB performance at low temperatures.","PeriodicalId":15579,"journal":{"name":"Journal of Electrochemical Energy Conversion and Storage","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135696210","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}
Abstract An environmental-friendly supercapacitor based on aqueous electrolyte was fabricated. Electrodes with conductive spider nest–shaped three-dimensional(3D)porous structure was prepared for the assembly of symmetric supercapacitors. The nickel foam was modified by multiwalled carbon nanotubes and β-cyclodextrin. The construction of spider nest was stabilized via the chemical bond inside carbon nanotubes, π-π stack effects among carbon nanotubes, and physical adsorption between nickel foam and carbon nanotubes substrate. The role of β-cyclodextrin is dispersant to prevent agglomeration of carbon nanotubes, thereby enhancing electroactive surface area of nickel foam, and improving the specific capacitance of the electrodes. Furthermore, the electrodes exhibited excellent rate capability. The obtained symmetrical supercapacitors exhibited excellent power density of 17561.3 W kg−1, good specific capacitance of 398.8 F g−1, and energy density of 154.8 Wh kg−1 for 4000 cycles with outstanding cycling stability. In addition, the specific capacitance, energy density, and power density of the supercapacitor operating in seawater were found to be 100.2 F g−1, 17.8 Wh kg−1, and 2568 Wh kg−1, respectively, for 3000 cycles. Overall, our findings indicate that the supercapacitor could stably operate in seawater and shows potential for use as an eco-friendly power supply to marine engineering equipment.
摘要制备了一种基于水电解质的环境友好型超级电容器。制备了具有导电蜘蛛巢状三维多孔结构的电极，用于对称超级电容器的组装。采用多壁碳纳米管和β-环糊精对泡沫镍进行改性。通过碳纳米管内部的化学键、碳纳米管之间的π-π堆叠效应以及泡沫镍与碳纳米管衬底之间的物理吸附来稳定蜘蛛网的结构。β-环糊精起到分散剂的作用，防止碳纳米管团聚，从而增大泡沫镍的电活性表面积，提高电极的比电容。此外，电极表现出优异的速率性能。所制得的对称型超级电容器具有优异的功率密度(17561.3 W kg−1)、良好的比电容(398.8 F g−1)和能量密度(154.8 Wh kg−1)，可循环4000次，且具有良好的循环稳定性。此外，在海水中运行3000次时，超级电容器的比电容、能量密度和功率密度分别为100.2 F g−1、17.8 Wh kg−1和2568 Wh kg−1。总的来说，我们的研究结果表明，超级电容器可以在海水中稳定运行，并显示出作为海洋工程设备的环保电源的潜力。
{"title":"Supercapacitors based on spider nest shaped nickel foam electrodes operating in seawater","authors":"Haiying Li, Yuchen Hui, Zunbin Xia, Huixin Wang","doi":"10.1115/1.4063612","DOIUrl":"https://doi.org/10.1115/1.4063612","url":null,"abstract":"Abstract An environmental-friendly supercapacitor based on aqueous electrolyte was fabricated. Electrodes with conductive spider nest–shaped three-dimensional(3D)porous structure was prepared for the assembly of symmetric supercapacitors. The nickel foam was modified by multiwalled carbon nanotubes and β-cyclodextrin. The construction of spider nest was stabilized via the chemical bond inside carbon nanotubes, π-π stack effects among carbon nanotubes, and physical adsorption between nickel foam and carbon nanotubes substrate. The role of β-cyclodextrin is dispersant to prevent agglomeration of carbon nanotubes, thereby enhancing electroactive surface area of nickel foam, and improving the specific capacitance of the electrodes. Furthermore, the electrodes exhibited excellent rate capability. The obtained symmetrical supercapacitors exhibited excellent power density of 17561.3 W kg−1, good specific capacitance of 398.8 F g−1, and energy density of 154.8 Wh kg−1 for 4000 cycles with outstanding cycling stability. In addition, the specific capacitance, energy density, and power density of the supercapacitor operating in seawater were found to be 100.2 F g−1, 17.8 Wh kg−1, and 2568 Wh kg−1, respectively, for 3000 cycles. Overall, our findings indicate that the supercapacitor could stably operate in seawater and shows potential for use as an eco-friendly power supply to marine engineering equipment.","PeriodicalId":15579,"journal":{"name":"Journal of Electrochemical Energy Conversion and Storage","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135696204","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}
Abstract The porosity of the cathode in a lithium-oxygen battery is a crucial parameter that influences oxygen transport and active surface area availability. This study explores various cathode models with different initial porosity distributions and analyses the porosity evolution during discharge. The objective is to maximize the active surface area utilization of the cathode and increase the battery's discharge capacity. The simulations employ a recently developed Lattice Boltzmann method (LBM) model proposed by Chen et al. (Chen, S., B. Yang, and C. Zheng, Simulation of double-diffusive convection in fluid-saturated porous media by lattice Boltzmann method. International Journal of Heat and Mass Transfer, 2017. 108: p. 1501-1510.), which is capable of handling spatial and temporal variations in diffusion coefficient values. The results demonstrate that a hierarchical porous cathode provides a better specific capacity than a uniform porous cathode with the same average initial porosity. The specific capacity increases as the magnitude of initial porosity variation in the domain increases. Furthermore, incorporating oxygen channels improves oxygen transport in the cathode and offers a better specific capacity than the hierarchical porous cathode. A combination of hierarchical porous media and oxygen channels delivers the best specific capacity among all the other cathode models, as it efficiently balances oxygen transport and active surface area.
锂氧电池正极孔隙率是影响氧传输和活性表面积利用率的重要参数。研究了不同初始孔隙率分布的阴极模型，分析了放电过程中孔隙率的演变规律。目标是最大限度地提高阴极的有效表面积利用率，增加电池的放电容量。本文采用Chen等人(Chen, S.， B. Yang, C. Zheng)提出的晶格玻尔兹曼方法(Lattice Boltzmann method, LBM)模型模拟饱和多孔介质中双扩散对流。国际传热与传质学报，2017。108: p. 1501-1510.)，它能够处理扩散系数值的空间和时间变化。结果表明，在平均初始孔隙率相同的情况下，分层多孔阴极比均匀多孔阴极具有更好的比容量。比容随孔隙度变化幅度的增大而增大。此外，结合氧通道改善了阴极中的氧运输，并提供了比分层多孔阴极更好的比容量。分层多孔介质和氧通道的组合在所有其他阴极模型中提供了最好的比容量，因为它有效地平衡了氧运输和活性表面积。
{"title":"Lattice Boltzmann Simulations of non-homogeneous Li-O2 Battery Cathode: the effect of spatial and temporal porosity variations","authors":"Ajeesh Mohan T, Jithin M, Malay Das","doi":"10.1115/1.4063489","DOIUrl":"https://doi.org/10.1115/1.4063489","url":null,"abstract":"Abstract The porosity of the cathode in a lithium-oxygen battery is a crucial parameter that influences oxygen transport and active surface area availability. This study explores various cathode models with different initial porosity distributions and analyses the porosity evolution during discharge. The objective is to maximize the active surface area utilization of the cathode and increase the battery's discharge capacity. The simulations employ a recently developed Lattice Boltzmann method (LBM) model proposed by Chen et al. (Chen, S., B. Yang, and C. Zheng, Simulation of double-diffusive convection in fluid-saturated porous media by lattice Boltzmann method. International Journal of Heat and Mass Transfer, 2017. 108: p. 1501-1510.), which is capable of handling spatial and temporal variations in diffusion coefficient values. The results demonstrate that a hierarchical porous cathode provides a better specific capacity than a uniform porous cathode with the same average initial porosity. The specific capacity increases as the magnitude of initial porosity variation in the domain increases. Furthermore, incorporating oxygen channels improves oxygen transport in the cathode and offers a better specific capacity than the hierarchical porous cathode. A combination of hierarchical porous media and oxygen channels delivers the best specific capacity among all the other cathode models, as it efficiently balances oxygen transport and active surface area.","PeriodicalId":15579,"journal":{"name":"Journal of Electrochemical Energy Conversion and Storage","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136060933","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}
Zhigang He, Xianggan Ni, Chaofeng Pan, Weiquan Li, Shaohua Han
Abstract Under different usage scenarios of various electric vehicles (EVs), it becomes difficult to estimate the battery state of health (SOH) quickly and accurately. This paper proposes a SOH estimation method based on EVs' charging process history data. First, data processing processes for practical application scenarios are established. Then the health indicators (HIs) that directly or indirectly reflect the driver's charging behavior in the charging process are used as the model's input, and the ensemble empirical mode decomposition (EEMD) is introduced to remove the noise brought by capacity regeneration. Subsequently, the maximum information coefficient (MIC) - principal component analysis (PCA) algorithm is employed to extract significant HIs. Eventually, the global optimal nonlinear degradation relationship between HIs and capacity is learned based on Bayesian optimization (BO)-Gaussian process regression (GPR). Approximate battery degradation models for practical application scenarios are obtained. This paper validates the proposed method from three perspectives: models, vehicles, and regions. The results show that the method has better prediction accuracy and generalization capability and lower computational cost, which provides a solution for future online health state prediction based on a large amount of real-time operational data.
{"title":"Power batteries state of health estimation of pure electric vehicles for charging process","authors":"Zhigang He, Xianggan Ni, Chaofeng Pan, Weiquan Li, Shaohua Han","doi":"10.1115/1.4063430","DOIUrl":"https://doi.org/10.1115/1.4063430","url":null,"abstract":"Abstract Under different usage scenarios of various electric vehicles (EVs), it becomes difficult to estimate the battery state of health (SOH) quickly and accurately. This paper proposes a SOH estimation method based on EVs' charging process history data. First, data processing processes for practical application scenarios are established. Then the health indicators (HIs) that directly or indirectly reflect the driver's charging behavior in the charging process are used as the model's input, and the ensemble empirical mode decomposition (EEMD) is introduced to remove the noise brought by capacity regeneration. Subsequently, the maximum information coefficient (MIC) - principal component analysis (PCA) algorithm is employed to extract significant HIs. Eventually, the global optimal nonlinear degradation relationship between HIs and capacity is learned based on Bayesian optimization (BO)-Gaussian process regression (GPR). Approximate battery degradation models for practical application scenarios are obtained. This paper validates the proposed method from three perspectives: models, vehicles, and regions. The results show that the method has better prediction accuracy and generalization capability and lower computational cost, which provides a solution for future online health state prediction based on a large amount of real-time operational data.","PeriodicalId":15579,"journal":{"name":"Journal of Electrochemical Energy Conversion and Storage","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135742204","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}
Huanwei Xu, Shi-Shuang Xiong, Wei Li, Lingfeng Wu, Zhonglai Wang
Temperature is a critical factor affecting the performance and safety of battery packs of electric vehicles (EVs). The design of liquid cooling plates based on mini-channels has always been the research hotspots of battery thermal management systems (BTMS). This paper investigates the effect of adding vortex generators (VGs) to the liquid cooling channel on the heat dissipation capacity and temperature uniformity of the battery. The shape of the vortex generators (triangle, trapezoid, and semicircle), placement position (middle, inlet, and outlet of the channel), different flow rates, and different number of channels on the heat dissipation of the battery are systematically analysed. The research results indicate that: (1) The semi-circular vortex generator has better heat dissipation and a relatively lower impact on pressure drop than the triangular and trapezoidal vortex generators (2) The effect of adding vortex generators is more obvious when the flow rate is small in the cooling channels. When the flow velocity is 0.025 m/s, the heat dissipation performance can be increased by 7.4%. (3) When the cross-sectional area of the inlet is fixed, the heat dissipation effect of more channels is better. The average temperature of three and seven cooling channels decreases with a decrease of 8.87%. (4) The temperature difference can be effectively reduced when the vortex generators are concentrated near the outlet of the flow outlet. Its temperature difference is lower than that when the vortex generators are placed near the inlet, with a decrease of 10.5%.
{"title":"Heat transfer improvement of prismatic lithium-ion batteries via a mini-channel liquid-cooling plate with vortex generators","authors":"Huanwei Xu, Shi-Shuang Xiong, Wei Li, Lingfeng Wu, Zhonglai Wang","doi":"10.1115/1.4063324","DOIUrl":"https://doi.org/10.1115/1.4063324","url":null,"abstract":"\u0000 Temperature is a critical factor affecting the performance and safety of battery packs of electric vehicles (EVs). The design of liquid cooling plates based on mini-channels has always been the research hotspots of battery thermal management systems (BTMS). This paper investigates the effect of adding vortex generators (VGs) to the liquid cooling channel on the heat dissipation capacity and temperature uniformity of the battery. The shape of the vortex generators (triangle, trapezoid, and semicircle), placement position (middle, inlet, and outlet of the channel), different flow rates, and different number of channels on the heat dissipation of the battery are systematically analysed. The research results indicate that: (1) The semi-circular vortex generator has better heat dissipation and a relatively lower impact on pressure drop than the triangular and trapezoidal vortex generators (2) The effect of adding vortex generators is more obvious when the flow rate is small in the cooling channels. When the flow velocity is 0.025 m/s, the heat dissipation performance can be increased by 7.4%. (3) When the cross-sectional area of the inlet is fixed, the heat dissipation effect of more channels is better. The average temperature of three and seven cooling channels decreases with a decrease of 8.87%. (4) The temperature difference can be effectively reduced when the vortex generators are concentrated near the outlet of the flow outlet. Its temperature difference is lower than that when the vortex generators are placed near the inlet, with a decrease of 10.5%.","PeriodicalId":15579,"journal":{"name":"Journal of Electrochemical Energy Conversion and Storage","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2023-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47923316","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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