Elżbieta Frąckowiak

Supercapacitors : materials, systems, and applications

GENERAL PRINCIPLES OF ELECTROCHEMISTRY Equilibrium Electrochemistry Ionics Dynamic Electrochemistry GENERAL PROPERTIES OF ELECTROCHEMICAL CAPACITORS Introduction Capacitor Principles Electrochemical Capacitors Summary ELECTROCHEMICAL TECHNIQUES Electrochemical Apparatus Electrochemical Cell Electrochemical Interface: Supercapacitors Most Used Electrochemical Techniques ELECTRICAL DOUBLE-LAYER CAPACITORS AND CARBONS FOR EDLCS Introduction The Electrical Double Layer Types of Carbons Used for EDLCs Capacitance versus Pore Size Evidence of Desolvation of Ions Performance Limitations: Pore Accessibility or Saturation of Porosity Beyond the Double-Layer Capacitance in Microporous Carbons Conclusions MODERN THEORIES OF CARBON-BASED ELECTROCHEMICAL CAPACITORS Introduction Classical Theories Recent Developments Concluding Remarks ELECTRODE MATERIALS WITH PSEUDOCAPACITIVE PROPERTIES Introduction Conducting Polymers in Supercapacitor Application Metal Oxide/Carbon Composites Pseudocapacitive Effect of Heteroatoms Present in the Carbon Network Nanoporous Carbons with Electrosorbed Hydrogen Electrolytic Solutions - A Source of Faradaic Reactions Conclusions - Profits and Disadvantages of Pseudocapacitive Effects LI-ION-BASED HYBRID SUPERCAPACITORS IN ORGANIC MEDIUM Introduction Voltage Limitation of Conventional EDLCs Hybrid Capacitor Systems Material Design for NHC Conclusion ASYMMETRIC AND HYBRID DEVICES IN AQUEOUS ELECTROLYTES Introduction Aqueous Hybrid (Asymmetric) Devices Aqueous Asymmetric Electrochemical Capacitors Tantalum Oxide-Ruthenium Oxide Hybrid Capacitors Perspectives EDLCS BASED ON SOLVENT-FREE IONIC LIQUIDS Introduction Carbon Electrode/Ionic Liquid Interface Ionic Liquids Carbon Electrodes Supercapacitors Concluding Remarks MANUFACTURING OF INDUSTRIAL SUPERCAPACITORS Introduction Cell Components Cell Design Module Design Conclusions and Perspectives SUPERCAPACITOR MODULE SIZING AND HEAT MANAGEMENT UNDER ELECTRIC, THERMAL, AND AGING CONSTRAINTS Introduction Electrical Characterization Thermal Modeling Supercapacitor Lifetime Supercapacitor Module Sizing Methods Applications TESTING OF ELECTROCHEMICAL CAPACITORS Introduction Summaries of DC Test Procedures Applicatin of the Test Procedures to Carbon/Carbon Devices Testing of Hybrid, Pseudocapacitive Devices Relationships between AC Impedance and DC Testing Uncertainties in Ultracapacitor Data Interpretation Summary RELIABILITY OF ELECTROCHEMICAL CAPACITORS Introduction Reliability Basics Cell Reliability System Reliability Assessment of Cell Reliability Reliability of Practical Systems Increasing System Reliability System Design Example MARKET AND APPLICATIONS OF ELECTROCHEMICAL CAPACITORS Introduction: Principles and History Commerical Designs: DC Power Applications Energy Conservation and Energy Harvesting Applications Technology Combination Applications Electricity Grid Applications Conclusions

Supercapacitor based on activated carbon and polyethylene oxide–KOH–H2O polymer electrolyte

For the first time, a totally solid state electric double layer capacitor has been fabricated using an alkaline polymer electrolyte and an activated carbon powder as electrode material. The polymer electrolyte serves both as separator as well as electrode binder. The capacitor has a three-layer structure: electrode–electrolyte–electrode with a final thickness of ca. 1.5–2 mm, diameter of 1.8 cm (surface of 2.5 cm2) and a mass of ca. 300–500 mg. Cyclic voltammetry, galvanostatic cycling and impedance spectroscopy have been used for the determination of the electrochemical performance of prototype capacitors and a capacity of ca. 1.7–3.0 F for a 1 V voltage range has been measured.

Passivation of zinc in alkaline solution effected by chromates and CrO3-graphite system

Electrochemical properties of porous zinc electrode in alkaline solution have been modified by the additive of chromium compounds such as chromates and CrO3–graphite system. Insertion of chromates inside the zinc electrode caused the limited solubility of the anodic dissolution products and their retention in the electrode interior. Different behaviour of the passivated zinc electrode was observed depending on cation of the used chromate. The improvement of cyclic performance of zinc has also been noted after the electrode is admixed with CrO3–graphite system containing intercalated/incorporated oxide. Electrochemical properties of zinc electrode strongly depend on the way of chromium insertion to active material of anode. Anodic and cathodic charges have been measured during potentiodynamic cycles for the observation of passivating effect.