Advanced Fluoride-Based Materials for Energy Conversion

Tsuyoshi Nakajima, Henri Groult

• Publisher: Elsevier
• Year: 2015
• Print ISBN: 9780128006795
• eBook ISBN: 9780128007129
• Topic: Technology & Engineering
• Subtopic: Inorganic Chemistry
• Index: Technology & Engineering

Advanced Fluoride-Based Materials for Energy Conversion provides thorough and applied information on new fluorinated materials for chemical energy devices, exploring the electrochemical properties and behavior of fluorinated materials in lithium ion and sodium ion batteries, fluoropolymers in fuel cells, and fluorinated carbon in capacitors, while also exploring synthesis applications, and both safety and stability issues.As electronic devices, from cell phones to hybrid and electric vehicles, are increasingly common and prevalent in modern lives and require dependable, stable chemical energy devices with high-level functions are becoming increasingly important. As research and development in this area progresses rapidly, fluorine compounds play a critical role in this rapid progression. Fluorine, with its small size and the highest electronegativity, yields stable compounds under various conditions for utilization as electrodes, electrolytes, and membranes in energy devices.The book is an ideal reference for the chemist, researcher, technician, or academic, presenting valuable, current insights into the synthesis of fluorine compounds and fluorination reactions using fluorinating agents.- Provides thorough and applied information on new fluorinated materials for chemical energy devices- Describes the emerging role of stable energy devices with high-level functions and the research surrounding the technology- Ideal for the chemist, research, technician, or academic seeking current insights into the synthesis of fluorine compounds and fluorination reactions using fluorinating agents

Chapter 1

High Performance Lithium-Ion Batteries Using Fluorinated Compounds

Zonghai Chen, Zhengcheng Zhang, and Khalil Amine Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL, USA

Abstract

Safe lithium ion batteries with long life and high energy density have long been a promising energy storage technology for emerging applications in automobiles and smart grids. Development of functionalized electrolytes is an effective approach to dramatically improve the performance of these batteries. In this chapter, several classes of fluorinated electrolyte components will be introduced and their mechanism to improve the battery performance discussed. The fluorinated compounds include (1) electrolyte additives that form a stable artificial solid-electrolyte interphase, (2) fluorinated redox shuttles for overcharge protection and automatic capacity balance of lithium ion batteries, and (3) fluorinated solvents to enable high voltage cathode materials.

Keywords

Battery safety; Electrolyte; High voltage cathode; Lithium-ion battery; Redox shuttle; Solid-electrolyte interphase

Chapter Outline

1.1 Introduction 1

1.2 Stabilization of Lithiated Anodes 2

1.2.1 Modification of SEI Layer 5

1.2.2 Artificial SEI Layer 7

1.3 Fluorinated Redox Shuttles 13

1.4 High Voltage Electrolytes 19

1.5 Closing Remarks 29

Acknowledgments 29

References 30

1.1. Introduction

Lithium-ion batteries have been the dominant energy storage technology for powering modern portable electronics. There is also a global effort on R&D of advanced lithium-ion batteries for propulsion and stationary applications in smart grids. The major technological barriers that hinder the realization of these emerging applications include (1) high cost, (2) insufficient life, (3) insufficient energy density, and (4) intrinsically poor safety characteristics. These barriers can be partially tackled by developing advanced electrode materials with a better structural stability, developing materials with higher energy density, and/or using low-cost starting materials and manufacturing processes. High energy-density materials are of great interest since they can lead to an overall reduction in the battery size, resulting in a large saving on other materials like the electrolyte and separator. These barriers can also be addressed by developing functionalized electrolytes that suppress the side reactions between the electrode materials and the electrolytes; these side reactions are the major contributors to the degradation of battery performance.

The current lithium-ion batteries generally use graphitic carbons as the anode material, a lithium transition metal oxide as the cathode material, and a solution of LiPF₆ in a blend solvent of alkyl carbonates as the electrolyte. The electrolyte in the battery is used as the lithium-ion conducting medium to transport lithium ions between the anode and cathode. The chemical–electrochemical reactions leading to performance degradation, as well as a potential safety hazard, mostly occur at the interface between the electrode material and the nonaqueous electrolyte, where the electrolyte components can act as either the reactant or the dilution medium that promotes detrimental reactions [1,2]. In an ideal system, the solvent should have a combination of several physical–chemical properties. First, it should be able to dissolve a fairly high concentration of lithium salts for high lithium-ion conductivity. Second, the energy level of the highest occupied molecular orbital (HOMO) of the solvents should be low enough for good resistance to oxidation by the delithiated cathode. Third, the energy level of the lowest unoccupied molecular orbital (LUMO) of the solvents should be high enough to prevent the reduction by lithiated anode materials. So far, an electrolyte that meets the above three requirements has not been identified. For instance, the LUMOs of currently used carbonates are substantially lower than the Fermi energy level of lithium, and hence, they are thermodynamically incompatible with lithium metal and lithiated graphite. The long-term stability of lithiated graphite with the presence of nonaqueous electrolytes can only be kinetically achieved with the presence of the solid-electrolyte interphase (SEI) [3–5], which is a thin layer of an organic–inorganic composite deposited on the surface of a graphitic electrode and acts as a kinetic barrier to protect the lithiated graphite from rapid reaction with the nonaqueous electrolyte. Recently, a massive effort has been devoted to developing cathode materials with high specific capacity and high voltage to meet the energy requirements for plug-in hybrid electric vehicles and full electric vehicles [6–10]. These R&D efforts have pushed the working potential of the cathode materials beyond the thermodynamic limit of the carbonate solvents, and an advanced electrolyte is highly desired to enable high-voltage cathodes [11,12]. Even within a well-characterized lithium-ion chemistry, the working potential of electrode materials can be driven beyond the electrochemically stable window of solvents during overcharge abuse, which can occur during the normal operation of an off-balance lithium-ion battery pack [13–16].

In this chapter, emphasis will be placed on advanced electrolytes with fluorinated components, including (1) advanced electrolyte additives that stabilize lithiated anodes; (2) fluorinated redox shuttles for overcharge protection and automatic capacity balance of the lithium-ion battery pack; and (3) advanced high-volt...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Contributors
• Preface
• Chapter 1. High Performance Lithium-Ion Batteries Using Fluorinated Compounds
• Chapter 2. Electrochemical Behavior of Surface-Fluorinated Cathode Materials for Lithium Ion Battery
• Chapter 3. Fluoride Cathodes for Secondary Batteries
• Chapter 4. Fluorosulfates and Fluorophosphates As New Cathode Materials for Lithium Ion Battery
• Chapter 5. Fluorohydrogenate Ionic Liquids, Liquid Crystals, and Plastic Crystals
• Chapter 6. Novel Fluorinated Solvents and Additives for Lithium-Ion Batteries
• Chapter 7. Safety Improvement of Lithium Ion Battery by Organofluorine Compounds
• Chapter 8. Artificial SEI for Lithium-Ion Battery Anodes: Impact of Fluorinated and Nonfluorinated Additives
• Chapter 9. Surface Modification of Carbon Anodes for Lithium Ion Batteries by Fluorine and Chlorine
• Chapter 10. Application of Polyvinylidene Fluoride Binders in Lithium-Ion Battery
• Chapter 11. Electrodeposition of Polypyrrole on CFx Powders Used as Cathode in Primary Lithium Battery
• Chapter 12. New Nano-C–F Compounds for Nonrechargeable Lithium Batteries
• Chapter 13. Recent Advances on Quasianhydrous Fuel Cell Membranes
• Chapter 14. The Use of Per-Fluorinated Sulfonic Acid (PFSA) Membrane as Electrolyte in Fuel Cells
• Chapter 15. Surface-Fluorinated Carbon Materials for Supercapacitor
• Chapter 16. Fluorine Chemistry for Negative Electrode in Sodium and Lithium Ion Batteries
• Chapter 17. Application of Carbon Materials Derived from Fluorocarbons in an Electrochemical Capacitor
• Index