Pub Date : 2018-06-27DOI: 10.5772/INTECHOPEN.73131
Ya-Qin Wang, Guoxin Zhang
This chapter includes elaborately selected recent literatures on electrochemical energy storing in symmetric supercapacitors (SSCs) with high operating voltages (voltage >1.6 V) and high specific energy. SSCs are a typical sort of electrochemical capacitors with larger energy density than conventional capacitors; by involving electrode materials with stable interfaces (for instance, nitrogen-doped carbon materials) and electrolytes with wide safe potential window (for instance, ionic liquids), they can supply competitive energy relative to batteries. Fundamentals of SSCs are first introduced, aiming at clarifying some critical interfacial phenomena that are critical to enhance overall capacitive performance. State-of-the-art SSCs are included as demonstrations from the aspects of both enhanced capacitances and expanded voltages. We also provide a few feasible strategies for the design high-voltage/energy SSCs such as using inactive electrode materials.
{"title":"Toward High-Voltage/Energy Symmetric Supercapacitors via Interface Engineering","authors":"Ya-Qin Wang, Guoxin Zhang","doi":"10.5772/INTECHOPEN.73131","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.73131","url":null,"abstract":"This chapter includes elaborately selected recent literatures on electrochemical energy storing in symmetric supercapacitors (SSCs) with high operating voltages (voltage >1.6 V) and high specific energy. SSCs are a typical sort of electrochemical capacitors with larger energy density than conventional capacitors; by involving electrode materials with stable interfaces (for instance, nitrogen-doped carbon materials) and electrolytes with wide safe potential window (for instance, ionic liquids), they can supply competitive energy relative to batteries. Fundamentals of SSCs are first introduced, aiming at clarifying some critical interfacial phenomena that are critical to enhance overall capacitive performance. State-of-the-art SSCs are included as demonstrations from the aspects of both enhanced capacitances and expanded voltages. We also provide a few feasible strategies for the design high-voltage/energy SSCs such as using inactive electrode materials.","PeriodicalId":369044,"journal":{"name":"Supercapacitors - Theoretical and Practical Solutions","volume":"21 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113988893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-06-27DOI: 10.5772/INTECHOPEN.73000
L. Thekkekara
Direct laser writing is a single-step fabrication technique for the micro and nanostructures even below the sub-diffraction limits. In recent times, the technique is adapted to the fabrication of on-chip energy storages with additional features of flexibility and stretchability. The major category of the energy storages taken into consideration for laser writing belongs to the family of supercapacitors which is known for the high rate of charge transfer, longer life spans and lesser charging times in comparison with traditional batteries. The technology explores the possibilities of non-explosive all solid-state energy storage integration with portable and wearable applications. These features can enable the development of self-powered autonomous devices, vehicles and self-reliant infrastructures. In this chapter, we discuss the progress, challenges and perspectives of micro-supercapacitors fabricated using direct laser writing.
{"title":"Direct Laser Writing of Supercapacitors","authors":"L. Thekkekara","doi":"10.5772/INTECHOPEN.73000","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.73000","url":null,"abstract":"Direct laser writing is a single-step fabrication technique for the micro and nanostructures even below the sub-diffraction limits. In recent times, the technique is adapted to the fabrication of on-chip energy storages with additional features of flexibility and stretchability. The major category of the energy storages taken into consideration for laser writing belongs to the family of supercapacitors which is known for the high rate of charge transfer, longer life spans and lesser charging times in comparison with traditional batteries. The technology explores the possibilities of non-explosive all solid-state energy storage integration with portable and wearable applications. These features can enable the development of self-powered autonomous devices, vehicles and self-reliant infrastructures. In this chapter, we discuss the progress, challenges and perspectives of micro-supercapacitors fabricated using direct laser writing.","PeriodicalId":369044,"journal":{"name":"Supercapacitors - Theoretical and Practical Solutions","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131711153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-06-27DOI: 10.5772/INTECHOPEN.71565
S. Khan, R. Rajkumar, Wong YeeWan, A. Syed
This research provides a platform for a novel innovative approach toward an off-grid energy harvesting system for Maglev VAWT. This stand-alone system can make a difference for using small-scale electronic devices. The configuration presents a 200 W 12 V 16 Pole AFPMSG attached to Maglev VAWT of 14.5 cm radius and 60 cm of height. The energy harvesting circuit shows better efficiency in charging battery in all aspects compared to direct charging of battery regardless with or without converter. Based on analysis and results carried out in this research, all feasibility studies and information are provided for the next barrier.
{"title":"Supercapacitor-Based Hybrid Energy Harvesting for Low-Voltage System","authors":"S. Khan, R. Rajkumar, Wong YeeWan, A. Syed","doi":"10.5772/INTECHOPEN.71565","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.71565","url":null,"abstract":"This research provides a platform for a novel innovative approach toward an off-grid energy harvesting system for Maglev VAWT. This stand-alone system can make a difference for using small-scale electronic devices. The configuration presents a 200 W 12 V 16 Pole AFPMSG attached to Maglev VAWT of 14.5 cm radius and 60 cm of height. The energy harvesting circuit shows better efficiency in charging battery in all aspects compared to direct charging of battery regardless with or without converter. Based on analysis and results carried out in this research, all feasibility studies and information are provided for the next barrier.","PeriodicalId":369044,"journal":{"name":"Supercapacitors - Theoretical and Practical Solutions","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129595638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-06-27DOI: 10.5772/INTECHOPEN.73680
Fenghua Guo, N. Gupta, Xiaowei Teng
Supercapacitors are a class of energy storage devices that store energy by either ionic adsorption via an electrochemical double layer capacitive process or fast surface redox reaction via a pseudocapacitive process. Supercapacitors display fast charging and discharging performance and excellent chemical stability, which fill the gap between high energy density batteries and high-power-density electrostatic capacitors. In this book chapter, the authors have presented the current studies on improving the capacitive storage capacity of various electrode materials for supercapacitors, mainly focusing on the metal oxide electrode materials. In particular, the approaches that mathematically simulate the behavior of interaction between electrode materials and charge carriers subject to potentiodynamic conditions (e.g., cyclic voltammetry) have been described. These include a general relationship between current and voltage to describe overall electrokinetics during the charge transfer process and a more comprehensive numerical modeling that studies ionic transport and electrokinetics within a spherical solid particle. The two aforementioned types of mathematical analyses can provide fundamental understanding of the parameters governing the electrode reaction and mass transfer in the electrode material, and thus shed light on how to improve the storage capacity of supercapacitors.
{"title":"Enhancing Pseudocapacitive Process for Energy Storage Devices: Analyzing the Charge Transport Using Electro-kinetic Study and Numerical Modeling","authors":"Fenghua Guo, N. Gupta, Xiaowei Teng","doi":"10.5772/INTECHOPEN.73680","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.73680","url":null,"abstract":"Supercapacitors are a class of energy storage devices that store energy by either ionic adsorption via an electrochemical double layer capacitive process or fast surface redox reaction via a pseudocapacitive process. Supercapacitors display fast charging and discharging performance and excellent chemical stability, which fill the gap between high energy density batteries and high-power-density electrostatic capacitors. In this book chapter, the authors have presented the current studies on improving the capacitive storage capacity of various electrode materials for supercapacitors, mainly focusing on the metal oxide electrode materials. In particular, the approaches that mathematically simulate the behavior of interaction between electrode materials and charge carriers subject to potentiodynamic conditions (e.g., cyclic voltammetry) have been described. These include a general relationship between current and voltage to describe overall electrokinetics during the charge transfer process and a more comprehensive numerical modeling that studies ionic transport and electrokinetics within a spherical solid particle. The two aforementioned types of mathematical analyses can provide fundamental understanding of the parameters governing the electrode reaction and mass transfer in the electrode material, and thus shed light on how to improve the storage capacity of supercapacitors.","PeriodicalId":369044,"journal":{"name":"Supercapacitors - Theoretical and Practical Solutions","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121430414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-06-27DOI: 10.5772/INTECHOPEN.76339
Cheng Lian, Honglai Liu
The most urgent issue for supercapacitor is to improve their energy density so that they can better compete with batteries. To design materials and interfaces for supercapacitor with higher energy density requires a deeper understanding of the factors and contributions affecting the total capacitance. In our recent works, the classical density functional theory (CDFT) was developed and applied to study the electrode/electrolyte interface behaviors, to understand capacitive energy storage. For porous electrode materials, we studied the pore size effect, curvature effect, and the surface modification of porous materials on the capaci- tance. Thought CDFT, we have found that the curvature effects on convex and concave EDLs are drastically different and that materials with extensive convex surfaces will lead to maximized capacitance; CDFT also predicts oscillatory variation of capacitance with pore size, but the oscillatory behavior is magnified as the curvature increases; an increase in the ionophobicity of the nanopores leads to a higher capacity for energy storage, and a pore-like impurity can enter the pore, makes the pore ionophobic and storage more energy. We also find the mixture effect, which makes more counterions pack on and more co-ions leave from the electrode surface, leads to an increase of the counterion density within the EDL and thus a larger capacitance.
{"title":"Classical Density Functional Theory Insights for Supercapacitors","authors":"Cheng Lian, Honglai Liu","doi":"10.5772/INTECHOPEN.76339","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.76339","url":null,"abstract":"The most urgent issue for supercapacitor is to improve their energy density so that they can better compete with batteries. To design materials and interfaces for supercapacitor with higher energy density requires a deeper understanding of the factors and contributions affecting the total capacitance. In our recent works, the classical density functional theory (CDFT) was developed and applied to study the electrode/electrolyte interface behaviors, to understand capacitive energy storage. For porous electrode materials, we studied the pore size effect, curvature effect, and the surface modification of porous materials on the capaci- tance. Thought CDFT, we have found that the curvature effects on convex and concave EDLs are drastically different and that materials with extensive convex surfaces will lead to maximized capacitance; CDFT also predicts oscillatory variation of capacitance with pore size, but the oscillatory behavior is magnified as the curvature increases; an increase in the ionophobicity of the nanopores leads to a higher capacity for energy storage, and a pore-like impurity can enter the pore, makes the pore ionophobic and storage more energy. We also find the mixture effect, which makes more counterions pack on and more co-ions leave from the electrode surface, leads to an increase of the counterion density within the EDL and thus a larger capacitance.","PeriodicalId":369044,"journal":{"name":"Supercapacitors - Theoretical and Practical Solutions","volume":"80 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124948683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-06-27DOI: 10.5772/INTECHOPEN.73053
Jeeyoung Yoo
Pure ionic liquids (ILs) and IL mixtures in organic solvents have been investigated for higher operating voltages around 3.0–4.0 V. ILs have design flexibility due to the numerous possible combinations of anions and cations. Current research on ILs as electrolytes has focused on several ILs, including imidazolium and pyrrolidinium. At early stages, various ILs have been studied as salts of electrolyte with organic solvents like acetonitrile and propylene carbonate. Neat ILs have been applied for high-performance electrolyte, and some of them have been used as electrolyte (1-ethyl 3-methylimidazolium tetrafluoroborate). These liquid electrolytes need additional encapsulation; therefore, SCs applied ILs face difficulty in integration and manufacturing flexible devices. These drawbacks can be solved by adopting a polymer electrolyte because the ILs maintain the conductivity even when solidified, unlike a typical organic electrolyte. Common polymer matrixes such as PVdF, PMMA, and PVA have been suggested to embed ILs. Poly(ionic liquid) (PIL) is also studied. PIL is a polymer electrolyte containing a polymer backbone and an IL species in the monomer repeat unit. PIL-based polymer electrolytes have high ionic conductivity, wide electrochemical windows, and high thermal stability.
{"title":"Ionic Liquid for High Voltage Supercapacitor","authors":"Jeeyoung Yoo","doi":"10.5772/INTECHOPEN.73053","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.73053","url":null,"abstract":"Pure ionic liquids (ILs) and IL mixtures in organic solvents have been investigated for higher operating voltages around 3.0–4.0 V. ILs have design flexibility due to the numerous possible combinations of anions and cations. Current research on ILs as electrolytes has focused on several ILs, including imidazolium and pyrrolidinium. At early stages, various ILs have been studied as salts of electrolyte with organic solvents like acetonitrile and propylene carbonate. Neat ILs have been applied for high-performance electrolyte, and some of them have been used as electrolyte (1-ethyl 3-methylimidazolium tetrafluoroborate). These liquid electrolytes need additional encapsulation; therefore, SCs applied ILs face difficulty in integration and manufacturing flexible devices. These drawbacks can be solved by adopting a polymer electrolyte because the ILs maintain the conductivity even when solidified, unlike a typical organic electrolyte. Common polymer matrixes such as PVdF, PMMA, and PVA have been suggested to embed ILs. Poly(ionic liquid) (PIL) is also studied. PIL is a polymer electrolyte containing a polymer backbone and an IL species in the monomer repeat unit. PIL-based polymer electrolytes have high ionic conductivity, wide electrochemical windows, and high thermal stability.","PeriodicalId":369044,"journal":{"name":"Supercapacitors - Theoretical and Practical Solutions","volume":"4 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128975052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-12-20DOI: 10.5772/INTECHOPEN.71003
S. Lombardo, J. Phillips
The discharge time dependence of key parameters of electrostatic capacitors employing a dielectric composed of the oxide film formed on titanium via anodization, saturated with various aqueous ion solutions, that is tube-super dielectric materials (T-SDM), was thoroughly documented for the first time. The capacitance, dielectric constant, and energy density of novel paradigm supercapacitors (NPS) based on T-SDM saturated with various concentrations of NaNO 3 , NH 4 Cl, or KOH were all found to roll-off with decreasing dis- charge time in a fashion well described by simple power law relations. In contrast, power density, also well described by a simple power law, was found to increase with decreasing discharge time, in fact nearly reaching 100 W/cm 3 for both 30 wt% KOH and NaNO 3 solu-tion-based capacitors at 0.01 s, excellent performance for pulsed power. For all capacitors, the dielectric constant was tested, which was greater than 10 5 for discharge times >0.01 s, confirming the materials are in fact T-SDM. The energy density for most of the capacitors was greater than 80 J/cm 3 of dielectric at a discharge time of 100 s, once again demonstrating that these capacitors are competitive for energy storage not only with existing com- mercial supercapacitors but also with the best prototype carbon-based supercapacitors.
{"title":"Performance of Aqueous Ion Solution/Tube-Super Dielectric Material-Based Capacitors as a Function of Discharge Time","authors":"S. Lombardo, J. Phillips","doi":"10.5772/INTECHOPEN.71003","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.71003","url":null,"abstract":"The discharge time dependence of key parameters of electrostatic capacitors employing a dielectric composed of the oxide film formed on titanium via anodization, saturated with various aqueous ion solutions, that is tube-super dielectric materials (T-SDM), was thoroughly documented for the first time. The capacitance, dielectric constant, and energy density of novel paradigm supercapacitors (NPS) based on T-SDM saturated with various concentrations of NaNO 3 , NH 4 Cl, or KOH were all found to roll-off with decreasing dis- charge time in a fashion well described by simple power law relations. In contrast, power density, also well described by a simple power law, was found to increase with decreasing discharge time, in fact nearly reaching 100 W/cm 3 for both 30 wt% KOH and NaNO 3 solu-tion-based capacitors at 0.01 s, excellent performance for pulsed power. For all capacitors, the dielectric constant was tested, which was greater than 10 5 for discharge times >0.01 s, confirming the materials are in fact T-SDM. The energy density for most of the capacitors was greater than 80 J/cm 3 of dielectric at a discharge time of 100 s, once again demonstrating that these capacitors are competitive for energy storage not only with existing com- mercial supercapacitors but also with the best prototype carbon-based supercapacitors.","PeriodicalId":369044,"journal":{"name":"Supercapacitors - Theoretical and Practical Solutions","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129629234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-12-20DOI: 10.5772/INTECHOPEN.70694
R. Ramachandran, Fei Wang
Due to low energy characteristics such as energy density and cyclic life, it is mandatory to enhance the energy characteristics of the supercapacitors (ESs). Electrolytes have been recognized as the most prominent ingredients in electrochemical supercapacitor perfor- mance. Most commercially available ESs use organic electrolytes and have some advantage like wide operating voltage. However, compared with aqueous alternatives, organic electrolytes are expensive, flammable, and, in some cases, toxic. It is reliable to assert that even though aqueous electrolytes examined by a cramped working voltage, the ions pres- ent in them are yet capable of incredibly faster carrier rates than organic electrolytes and can achieve better performance of ESs. Thus, efforts turned toward enlarging the work - ing voltage window of aqueous electrolytes to increase overall operating potential and energy density of supercapacitor devices. This book chapter comprises the latest accom - plishments in this area and provides an insight into the aqueous electrolyte advancement.
{"title":"Electrochemical Capacitor Performance: Influence of Aqueous Electrolytes","authors":"R. Ramachandran, Fei Wang","doi":"10.5772/INTECHOPEN.70694","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.70694","url":null,"abstract":"Due to low energy characteristics such as energy density and cyclic life, it is mandatory to enhance the energy characteristics of the supercapacitors (ESs). Electrolytes have been recognized as the most prominent ingredients in electrochemical supercapacitor perfor- mance. Most commercially available ESs use organic electrolytes and have some advantage like wide operating voltage. However, compared with aqueous alternatives, organic electrolytes are expensive, flammable, and, in some cases, toxic. It is reliable to assert that even though aqueous electrolytes examined by a cramped working voltage, the ions pres- ent in them are yet capable of incredibly faster carrier rates than organic electrolytes and can achieve better performance of ESs. Thus, efforts turned toward enlarging the work - ing voltage window of aqueous electrolytes to increase overall operating potential and energy density of supercapacitor devices. This book chapter comprises the latest accom - plishments in this area and provides an insight into the aqueous electrolyte advancement.","PeriodicalId":369044,"journal":{"name":"Supercapacitors - Theoretical and Practical Solutions","volume":"101 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132921318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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