Aina Tian, Chen Yang, Yang Gao, Yan Jiang, C. Chang, Lujun Wang, Jiuchun Jiang
Battery aging is an inevitable macroscopic phenomenon in the use of the battery, which is characterized by capacity decline and power reduction. If the charging and discharging strategy does not adjusted with the aging state, it is easy to cause battery abuse and accelerate the decline. In order to avoid this situation, the aging model with consideration of the battery degradation is coupled into the pseudo-two-dimensional (P2D) model. An aging effect-aware finite element model that can describe battery physical information accurately is presented in this paper. The model parameters are divided into four parts: structure parameters, thermodynamic parameters, kinetic parameters and aging parameters. The identification experiments are designed based on the characteristics of these types of parameters. The decoupling and parameter identification methods of kinetic parameters according to the response characteristics of each parameter under specific excitation, and state of charge (SOC) partitioned range identification technology of aging parameters are proposed and verified. Finally, the aging effect-aware model and the identification parameters are verified under constant current (CC) and different dynamic conditions with different charge rate (C-rate). And the ability of the proposed model to track the aging trajectory in the whole life cycle is verified under various cycle conditions. The proposed model can be applied to aging mechanism analysis and health management from point of inner properties of the batteries.
{"title":"Aging effect-aware finite element model and parameter identification method of Lithium-ion battery","authors":"Aina Tian, Chen Yang, Yang Gao, Yan Jiang, C. Chang, Lujun Wang, Jiuchun Jiang","doi":"10.1115/1.4055463","DOIUrl":"https://doi.org/10.1115/1.4055463","url":null,"abstract":"\u0000 Battery aging is an inevitable macroscopic phenomenon in the use of the battery, which is characterized by capacity decline and power reduction. If the charging and discharging strategy does not adjusted with the aging state, it is easy to cause battery abuse and accelerate the decline. In order to avoid this situation, the aging model with consideration of the battery degradation is coupled into the pseudo-two-dimensional (P2D) model. An aging effect-aware finite element model that can describe battery physical information accurately is presented in this paper. The model parameters are divided into four parts: structure parameters, thermodynamic parameters, kinetic parameters and aging parameters. The identification experiments are designed based on the characteristics of these types of parameters. The decoupling and parameter identification methods of kinetic parameters according to the response characteristics of each parameter under specific excitation, and state of charge (SOC) partitioned range identification technology of aging parameters are proposed and verified. Finally, the aging effect-aware model and the identification parameters are verified under constant current (CC) and different dynamic conditions with different charge rate (C-rate). And the ability of the proposed model to track the aging trajectory in the whole life cycle is verified under various cycle conditions. The proposed model can be applied to aging mechanism analysis and health management from point of inner properties of the batteries.","PeriodicalId":15579,"journal":{"name":"Journal of Electrochemical Energy Conversion and Storage","volume":"1 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2022-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"63503807","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}
L. Hua, H. Fei, Linjie Zheng, Du Zhengyao, Tang Kewen
It is of great significance to develop efficient and robust oxygen evolution reaction (OER) electrocatalysts based on inexpensive and earth-abundant materials to enable water splitting as a future renewable energy source. Herein, the in situ grown CoMn-MOF-74 on nickel foam and their use as active electrodes for high-performance water-oxidation catalysis are reported. In alkaline media, the binder-free 3D electrode shows superior OER activity with a current density of 10 mA cm−2 at a small overpotential of 260 mV, a Tafel slope of 58.2 mV dec−1, as well as excellent stability, making it one of the most active OER catalysts. Such high performance is attributed to increased electrochemically-active areas, accelerated electron transport capability and the synergy between MOFs and Ni substrate. This work elucidates a promising electrode for electrochemical water oxidation and enriches direct application of MOF materials for future clean energy conversion and storage systems.
基于廉价且富含地球的材料开发高效、稳健的析氧反应（OER）电催化剂，使水分解成为未来的可再生能源，具有重要意义。本文报道了在泡沫镍上原位生长的CoMn-MOF-74及其作为高性能水氧化催化活性电极的应用。在碱性介质中，无粘合剂的3D电极显示出优异的OER活性，在260 mV的小过电位下，电流密度为10 mA cm−2，Tafel斜率为58.2 mV dec−1，以及优异的稳定性，使其成为最具活性的OER催化剂之一。这种高性能归因于增加的电化学活性区域、加速的电子传输能力以及MOFs和Ni衬底之间的协同作用。这项工作阐明了一种很有前途的电化学水氧化电极，并丰富了MOF材料在未来清洁能源转换和存储系统中的直接应用。
{"title":"In Situ Grown CoMn-Based Metal-Organic Framework on Nickel Foam as Efficient and Robust Electrodes for Electrochemical Oxygen Evolution Reaction","authors":"L. Hua, H. Fei, Linjie Zheng, Du Zhengyao, Tang Kewen","doi":"10.1115/1.4055462","DOIUrl":"https://doi.org/10.1115/1.4055462","url":null,"abstract":"\u0000 It is of great significance to develop efficient and robust oxygen evolution reaction (OER) electrocatalysts based on inexpensive and earth-abundant materials to enable water splitting as a future renewable energy source. Herein, the in situ grown CoMn-MOF-74 on nickel foam and their use as active electrodes for high-performance water-oxidation catalysis are reported. In alkaline media, the binder-free 3D electrode shows superior OER activity with a current density of 10 mA cm−2 at a small overpotential of 260 mV, a Tafel slope of 58.2 mV dec−1, as well as excellent stability, making it one of the most active OER catalysts. Such high performance is attributed to increased electrochemically-active areas, accelerated electron transport capability and the synergy between MOFs and Ni substrate. This work elucidates a promising electrode for electrochemical water oxidation and enriches direct application of MOF materials for future clean energy conversion and storage systems.","PeriodicalId":15579,"journal":{"name":"Journal of Electrochemical Energy Conversion and Storage","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2022-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43084965","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}
Buyi Zhang, Bei Fan, Zhi Huang, Kenneth Higa, V. Battaglia, R. Prasher
Dispersion drying is an essential step in an enormous number of research and industry fields, including self-assembly, membrane fabrication, printing, battery electrode fabrication, painting, and large-scale solar cell fabrication. The drying process of a dispersion directly influences the structure and properties of the resulting dried film. Thus, it is important to investigate the underlying physics of dispersion drying and the effects of different drying parameters. This article reviews modeling studies of coating drying processes, along with corresponding experimental observations. We have divided drying processes into two conceptual stages. In the first drying stage, liquid evaporation, particle sedimentation and Brownian motion compete and affect the particle distribution during drying and thus in the final film structure. We have included a comprehensive discussion of the influences of drying parameters, such as evaporation rate, particle sizes and temperature, on the above competition and the resulting film structure. A drying regime map describing where different drying phenomena dominate was formulated based on the literature. We also extended our discussion to the practical applications of battery slurry drying an essential step in conventional battery electrode manufacturing. In the second drying stage, the physics of porous drying and crack formation are reviewed. This review aims to provide a comprehensive understanding of dispersion drying mechanisms and to provide guidance in the design of film products with favorable structures and properties for targeted practical applications.
{"title":"A Review of Dispersion Film Drying Research","authors":"Buyi Zhang, Bei Fan, Zhi Huang, Kenneth Higa, V. Battaglia, R. Prasher","doi":"10.1115/1.4055392","DOIUrl":"https://doi.org/10.1115/1.4055392","url":null,"abstract":"\u0000 Dispersion drying is an essential step in an enormous number of research and industry fields, including self-assembly, membrane fabrication, printing, battery electrode fabrication, painting, and large-scale solar cell fabrication. The drying process of a dispersion directly influences the structure and properties of the resulting dried film. Thus, it is important to investigate the underlying physics of dispersion drying and the effects of different drying parameters. This article reviews modeling studies of coating drying processes, along with corresponding experimental observations. We have divided drying processes into two conceptual stages. In the first drying stage, liquid evaporation, particle sedimentation and Brownian motion compete and affect the particle distribution during drying and thus in the final film structure. We have included a comprehensive discussion of the influences of drying parameters, such as evaporation rate, particle sizes and temperature, on the above competition and the resulting film structure. A drying regime map describing where different drying phenomena dominate was formulated based on the literature. We also extended our discussion to the practical applications of battery slurry drying an essential step in conventional battery electrode manufacturing. In the second drying stage, the physics of porous drying and crack formation are reviewed. This review aims to provide a comprehensive understanding of dispersion drying mechanisms and to provide guidance in the design of film products with favorable structures and properties for targeted practical applications.","PeriodicalId":15579,"journal":{"name":"Journal of Electrochemical Energy Conversion and Storage","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2022-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47306733","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}
Solid oxide fuel cell(SOFC) is a clean and efficient energy utilization technology. Partial oxidation reforming(POX) can be used to simplify SOFC system structure, but its lower hydrogen production rate deteriorates system performance. A wise method may be combining anode off gas recirculation(AOGR) and cathode off gas recirculation(COGR) with POX. Thus, their influence on the coupled system of intermediate temperature SOFC and POX is researched in detail in this paper. Results show that the reforming process gradually changes from exothermic to endothermic as AOGR rate increases. Meanwhile, its oxygen demand declines sharply and the process can even be self-sustained without external air input at the AOGR rate of 0.5 and 0.6. The application of AOGR can improve electrical efficiency up to 51%, but at the expense of thermal efficiency. Excessive AOGR rates will result in decreased cell voltage and insufficient energy supply to the after-burner, so it should be restricted within a reasonable range and the best recommended value is 0.5. The application of COGR has little effect on fuel line parameters, so it cause little deterioration in electrical efficiency while improving thermal efficiency. Besides, cell voltage is also insensitive to it. The combination of AOGR and COGR can obtain better fuel economy and larger cogeneration scale simultaneously at the cost of a tiny electrical output power, while an optimal balance between three efficiencies is also achieved.
{"title":"Influence of off gas recirculation on the intermediate temperature SOFC with POX reformer","authors":"Siyuan Li, Zhe Zhang, Guo-xiang Li, Shuzhan Bai","doi":"10.1115/1.4055393","DOIUrl":"https://doi.org/10.1115/1.4055393","url":null,"abstract":"\u0000 Solid oxide fuel cell(SOFC) is a clean and efficient energy utilization technology. Partial oxidation reforming(POX) can be used to simplify SOFC system structure, but its lower hydrogen production rate deteriorates system performance. A wise method may be combining anode off gas recirculation(AOGR) and cathode off gas recirculation(COGR) with POX. Thus, their influence on the coupled system of intermediate temperature SOFC and POX is researched in detail in this paper. Results show that the reforming process gradually changes from exothermic to endothermic as AOGR rate increases. Meanwhile, its oxygen demand declines sharply and the process can even be self-sustained without external air input at the AOGR rate of 0.5 and 0.6. The application of AOGR can improve electrical efficiency up to 51%, but at the expense of thermal efficiency. Excessive AOGR rates will result in decreased cell voltage and insufficient energy supply to the after-burner, so it should be restricted within a reasonable range and the best recommended value is 0.5. The application of COGR has little effect on fuel line parameters, so it cause little deterioration in electrical efficiency while improving thermal efficiency. Besides, cell voltage is also insensitive to it. The combination of AOGR and COGR can obtain better fuel economy and larger cogeneration scale simultaneously at the cost of a tiny electrical output power, while an optimal balance between three efficiencies is also achieved.","PeriodicalId":15579,"journal":{"name":"Journal of Electrochemical Energy Conversion and Storage","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2022-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41998426","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}
Si material has a huge lithium storage capacity, but its huge volume change during charging and discharging makes it difficult to use. However, by nano-sizing Si material and building a coating structure, it can effectively reduce the capacity reduction caused by the expansion of Si material. In our experiment, dichlorodimethylsilane was used as the silicon source and carbon source for the deposition of silicon nanofibres and SiC-coated on a spherical graphite substrate, and then the SiC cladding was deposited without changing the temperature and silicon source, and only the C to H ratio in the atmosphere was controlled to build cladding layer. Simultaneous preparation of SiC@Si/G composites with silicon nanofibers and cladding structures by a single CVD process and single raw materials. The material has a silicon nanofiber structure and SiC coating structure. The presence of silicon is effective in providing very high capacity and the presence of the SiC layer is effective in improving the capacity retention of the composite material on the premise of increasing the Coulomb efficiency of the material. At a current density of 100 mAh g−1, the material has a reversible capacity of 647.3 mAh g−1 at first cycle. After 100 cycles, it has a 76.2 % retention rate. The electrodes can be extremely stable after cycling without significant swelling.
Si材料具有巨大的锂存储容量，但其在充放电过程中体积变化巨大，使用困难。而通过对Si材料进行纳米化，构建涂层结构，可以有效降低Si材料膨胀造成的容量降低。在我们的实验中，以二氯二甲基硅烷作为硅源和碳源，在球形石墨衬底上沉积硅纳米纤维和SiC包覆层，然后在不改变温度和硅源的情况下沉积SiC包覆层，仅控制大气中的C / H比来构建包覆层。采用单一CVD工艺和单一原料同时制备硅纳米纤维和包层结构SiC@Si/G复合材料该材料具有硅纳米纤维结构和SiC涂层结构。硅的存在可以有效地提供非常高的容量，SiC层的存在可以在提高材料库仑效率的前提下，有效地改善复合材料的容量保持。在电流密度为100 mAh g−1时，该材料在第一次循环时具有647.3 mAh g−1的可逆容量。经过100次循环后，它的留存率为76.2%。电极在循环后非常稳定，没有明显的肿胀。
{"title":"Preparation of SiC-coated silicon nanofiber/graphite composites as anode material for Li-ion batteries by CVD method","authors":"Mingqi Liu, Bei Liu, Rui Zhang, Zhiyong Xie, Peng Huang, Jiali Zhang","doi":"10.1115/1.4055312","DOIUrl":"https://doi.org/10.1115/1.4055312","url":null,"abstract":"\u0000 Si material has a huge lithium storage capacity, but its huge volume change during charging and discharging makes it difficult to use. However, by nano-sizing Si material and building a coating structure, it can effectively reduce the capacity reduction caused by the expansion of Si material. In our experiment, dichlorodimethylsilane was used as the silicon source and carbon source for the deposition of silicon nanofibres and SiC-coated on a spherical graphite substrate, and then the SiC cladding was deposited without changing the temperature and silicon source, and only the C to H ratio in the atmosphere was controlled to build cladding layer. Simultaneous preparation of SiC@Si/G composites with silicon nanofibers and cladding structures by a single CVD process and single raw materials. The material has a silicon nanofiber structure and SiC coating structure. The presence of silicon is effective in providing very high capacity and the presence of the SiC layer is effective in improving the capacity retention of the composite material on the premise of increasing the Coulomb efficiency of the material. At a current density of 100 mAh g−1, the material has a reversible capacity of 647.3 mAh g−1 at first cycle. After 100 cycles, it has a 76.2 % retention rate. The electrodes can be extremely stable after cycling without significant swelling.","PeriodicalId":15579,"journal":{"name":"Journal of Electrochemical Energy Conversion and Storage","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2022-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44289647","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}
Yan Wang, Hewu Wang, Qingshan Gao, Xiaohang Zhang, Xilong Zhang, Zunmin Liu
The heat pump system employed with a dual evaporator for battery cooling coupled with cabin comfort is an innovative thermal management method. It can be inferred that the refrigerant thermal load distribution can trigger temperature fluctuations for thermal performance of both battery and cabin. To trade-off between the thermal management demands of battery and cabin, this study proposed a strategy to promote the decreasing of battery temperature and to ensure battery thermal uniformity with a higher priority. Hence a transient refrigerant flow rate distribution scheme with a minimum flow rate to satisfy battery thermal demands was designed. The results showed a significant reduction in the temperature fluctuations for cabin thermal comfort and BTM thermal controlling. It offers a satisfactory reference for refrigerant thermal load distribution strategy applied with the heat pump system connected to the battery and cabin by the dual evaporator.
{"title":"Refrigerant flow distribution research for battery cooling coupled with cabin comfort based on dual-evaporator heat pump system for electric vehicle acceleration","authors":"Yan Wang, Hewu Wang, Qingshan Gao, Xiaohang Zhang, Xilong Zhang, Zunmin Liu","doi":"10.1115/1.4055274","DOIUrl":"https://doi.org/10.1115/1.4055274","url":null,"abstract":"\u0000 The heat pump system employed with a dual evaporator for battery cooling coupled with cabin comfort is an innovative thermal management method. It can be inferred that the refrigerant thermal load distribution can trigger temperature fluctuations for thermal performance of both battery and cabin. To trade-off between the thermal management demands of battery and cabin, this study proposed a strategy to promote the decreasing of battery temperature and to ensure battery thermal uniformity with a higher priority. Hence a transient refrigerant flow rate distribution scheme with a minimum flow rate to satisfy battery thermal demands was designed. The results showed a significant reduction in the temperature fluctuations for cabin thermal comfort and BTM thermal controlling. It offers a satisfactory reference for refrigerant thermal load distribution strategy applied with the heat pump system connected to the battery and cabin by the dual evaporator.","PeriodicalId":15579,"journal":{"name":"Journal of Electrochemical Energy Conversion and Storage","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2022-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46276350","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}
Waleed Zakri, Hassan Fagehi, Muapper Alhadri, A. Abutaleb, Siamak Farhad
Flexible lithium-ion batteries (LIBs) have a strong oncoming consumer market demand for use in wearable electronic devices, flexible smart electronics, roll-up displays, electronic shelf labels, active radio-frequency identification tags, implantable medical devices, and so forth. This market demand necessitates research and development of new flexible LIBs to fulfill the electrical energy and power requirements of these next-generation devices. In this study, we investigate the performance of a new flexible LIB made from semi-solid electrodes. The semi-solid electrodes are made by adding a mixture of electrode active material and conductive material to the organic liquid electrode. This gives a dense and viscous slurry so that all solid particles can move by acting pressure, shear, or bending forces to the battery. To study the performance of this battery we develop a 3D heterogeneous mathematical model that considers all necessary transport phenomena including the charge and mass transfer and electrochemical reactions at the continuum mechanics level on the reconstructed 3D structure of semi-solid electrodes. The finite element analysis (FEA) method was used to solve the governing equations using the COMSOL Multiphysics software package. The model is validated using experimental data for the flexible LIB made in the lab. Based on the developed model, several studies are conducted to understand the effect of the battery discharge rate and the operating temperature on the battery capacity. These studies recommend an operational range for the temperature and discharge rate for this flexible LIB.
{"title":"Three-dimensional Heterogeneous Modeling of a Flexible Lithium-ion Battery Made from Semi-Solid Electrodes","authors":"Waleed Zakri, Hassan Fagehi, Muapper Alhadri, A. Abutaleb, Siamak Farhad","doi":"10.1115/1.4055222","DOIUrl":"https://doi.org/10.1115/1.4055222","url":null,"abstract":"\u0000 Flexible lithium-ion batteries (LIBs) have a strong oncoming consumer market demand for use in wearable electronic devices, flexible smart electronics, roll-up displays, electronic shelf labels, active radio-frequency identification tags, implantable medical devices, and so forth. This market demand necessitates research and development of new flexible LIBs to fulfill the electrical energy and power requirements of these next-generation devices. In this study, we investigate the performance of a new flexible LIB made from semi-solid electrodes. The semi-solid electrodes are made by adding a mixture of electrode active material and conductive material to the organic liquid electrode. This gives a dense and viscous slurry so that all solid particles can move by acting pressure, shear, or bending forces to the battery. To study the performance of this battery we develop a 3D heterogeneous mathematical model that considers all necessary transport phenomena including the charge and mass transfer and electrochemical reactions at the continuum mechanics level on the reconstructed 3D structure of semi-solid electrodes. The finite element analysis (FEA) method was used to solve the governing equations using the COMSOL Multiphysics software package. The model is validated using experimental data for the flexible LIB made in the lab. Based on the developed model, several studies are conducted to understand the effect of the battery discharge rate and the operating temperature on the battery capacity. These studies recommend an operational range for the temperature and discharge rate for this flexible LIB.","PeriodicalId":15579,"journal":{"name":"Journal of Electrochemical Energy Conversion and Storage","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2022-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46724144","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}
Xiangjie Li, Yanfei Zhao, Yicheng Song, Junqian Zhang, Bo Lu
A macroscopic architecture design of lithium metal electrodes for solving the problem of extremely excessive lithium metal is proposed in this paper. By employing a simple mechanical processing method, macroscopic hollows within lithium foils are introduced, and consequently the amount of lithium metal is economized significantly. Cyclability of lithium foils with millimeter-size hollows is evaluated jointly via modeling and experiments. The results suggest that the well-designed macroscopic hollow causes controllable sacrifices of battery cycling performances and considerably boosts the utilization of lithium metal. The relationship of economization, cyclability and utilization of lithium metal is also discussed. The universality of the results is also verified in different battery systems. Meanwhile, the initial hollows are found to heal morphologically after a series of electrochemical cycles, and the existence of lithium metal in the healing product is also confirmed, indicating that hollows provide room for the in-plane lithium dendrite growth. Based on these findings, this work provides a new perspective on the architecture design of lithium metal electrodes.
{"title":"Macroscopic architecture design of lithium metal electrodes: impacts of millimeter-size hollows on economization, cyclability and utilization","authors":"Xiangjie Li, Yanfei Zhao, Yicheng Song, Junqian Zhang, Bo Lu","doi":"10.1115/1.4055195","DOIUrl":"https://doi.org/10.1115/1.4055195","url":null,"abstract":"\u0000 A macroscopic architecture design of lithium metal electrodes for solving the problem of extremely excessive lithium metal is proposed in this paper. By employing a simple mechanical processing method, macroscopic hollows within lithium foils are introduced, and consequently the amount of lithium metal is economized significantly. Cyclability of lithium foils with millimeter-size hollows is evaluated jointly via modeling and experiments. The results suggest that the well-designed macroscopic hollow causes controllable sacrifices of battery cycling performances and considerably boosts the utilization of lithium metal. The relationship of economization, cyclability and utilization of lithium metal is also discussed. The universality of the results is also verified in different battery systems. Meanwhile, the initial hollows are found to heal morphologically after a series of electrochemical cycles, and the existence of lithium metal in the healing product is also confirmed, indicating that hollows provide room for the in-plane lithium dendrite growth. Based on these findings, this work provides a new perspective on the architecture design of lithium metal electrodes.","PeriodicalId":15579,"journal":{"name":"Journal of Electrochemical Energy Conversion and Storage","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2022-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47474345","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}
Gang Qu, Wei Zhang, Q. Fu, Zuxiao Yu, Yuping Sheng, J. Chen
Currently, most of anode materials for lithium-ion batteries (LIBs) suffer from the problems of capacity degradation and reduction of cycle life due to the volume expansion and polarisation. Here we have successfully prepared helical carbon nanofibers (HCNFs) by a simple ethanol flame method (EFM) and tested their electrochemical performance as anode materials for LIBs. The results show that HCNFs possess high reversible capacity (specific capacity of 622.9 mAh·g−1 at a current density of 50 mA·g−1), good rate performance and excellent cycling stability (specific capacity of 395.6 mAh·g−1 after 100 cycles at a current density of 200 mA·g−1, coulombic efficiency of over 98 % and capacity retention of 94.41 %). HCNFs possess unique helical structure, which provide a strong support space for the intercalation/deintercalation in LIBs, and effectively alleviate the volume expansion and polarisation of the anode material. What's more, HCNFs exhibit excellent electrical conductivity and chemical stability. The facile preparation route and superior properties of HCNFs make it potential anode materials for LIBs.
{"title":"Electrochemical evaluation of helical carbon nanofibers prepared by ethanol flame method as anode materials of lithium-ion batteries","authors":"Gang Qu, Wei Zhang, Q. Fu, Zuxiao Yu, Yuping Sheng, J. Chen","doi":"10.1115/1.4055042","DOIUrl":"https://doi.org/10.1115/1.4055042","url":null,"abstract":"\u0000 Currently, most of anode materials for lithium-ion batteries (LIBs) suffer from the problems of capacity degradation and reduction of cycle life due to the volume expansion and polarisation. Here we have successfully prepared helical carbon nanofibers (HCNFs) by a simple ethanol flame method (EFM) and tested their electrochemical performance as anode materials for LIBs. The results show that HCNFs possess high reversible capacity (specific capacity of 622.9 mAh·g−1 at a current density of 50 mA·g−1), good rate performance and excellent cycling stability (specific capacity of 395.6 mAh·g−1 after 100 cycles at a current density of 200 mA·g−1, coulombic efficiency of over 98 % and capacity retention of 94.41 %). HCNFs possess unique helical structure, which provide a strong support space for the intercalation/deintercalation in LIBs, and effectively alleviate the volume expansion and polarisation of the anode material. What's more, HCNFs exhibit excellent electrical conductivity and chemical stability. The facile preparation route and superior properties of HCNFs make it potential anode materials for LIBs.","PeriodicalId":15579,"journal":{"name":"Journal of Electrochemical Energy Conversion and Storage","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2022-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48313151","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}
Benchmarks are provided for the evaluation of the effective coefficient for species diffusion, or electrical/thermal conduction, in structured porous media. The cases considered correspond to doubly-periodic rows of circular cylinders, for which a power series solution has been previously obtained, from complex variable theory. Both inline and staggered geometries are considered for three common configurations; inline square, rotated square, and equilateral geometries. From these mathematical solutions, values for the effective conduction/diffusion coefficient are readily constructed. The results are presented in terms of correlations for the ratio of effective-to-bulk conductivity/diffusivity, or microstructural parameter, as a function of porosity. It is shown that near identical results with the present analytical analysis are obtained using calculations based on a finite volume method, and also with a previous mathematical analysis for the case of inline square geometry. The present analytical solutions are also compared with two well-known correlations for random porous media, based on effective-medium and percolation theory. It is shown that agreement with the analytical solution, is not in general particularly good, and depends on the choice of parameters. The present results may be used as canonical data for comparative studies with numerical procedures used to enumerate microstructural parameters for arbitrary-shaped occlusions in random geometries.
{"title":"Effective diffusivity from analytical solution for banks of cylinders","authors":"S. Beale","doi":"10.1115/1.4055044","DOIUrl":"https://doi.org/10.1115/1.4055044","url":null,"abstract":"\u0000 Benchmarks are provided for the evaluation of the effective coefficient for species diffusion, or electrical/thermal conduction, in structured porous media. The cases considered correspond to doubly-periodic rows of circular cylinders, for which a power series solution has been previously obtained, from complex variable theory. Both inline and staggered geometries are considered for three common configurations; inline square, rotated square, and equilateral geometries. From these mathematical solutions, values for the effective conduction/diffusion coefficient are readily constructed. The results are presented in terms of correlations for the ratio of effective-to-bulk conductivity/diffusivity, or microstructural parameter, as a function of porosity. It is shown that near identical results with the present analytical analysis are obtained using calculations based on a finite volume method, and also with a previous mathematical analysis for the case of inline square geometry. The present analytical solutions are also compared with two well-known correlations for random porous media, based on effective-medium and percolation theory. It is shown that agreement with the analytical solution, is not in general particularly good, and depends on the choice of parameters. The present results may be used as canonical data for comparative studies with numerical procedures used to enumerate microstructural parameters for arbitrary-shaped occlusions in random geometries.","PeriodicalId":15579,"journal":{"name":"Journal of Electrochemical Energy Conversion and Storage","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2022-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47457814","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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