Lithium Batteries

Advanced Technologies and Applications

Bruno Scrosati, K. M. Abraham, Walter A. van Schalkwijk, Jusef Hassoun

• Publisher: Wiley
• Year: 2013
• ISBN:
  9781118615393
• Edition: 1
• Topic: Physical Sciences
• Subtopic: Physical & Theoretical Chemistry

Explains the current state of the science and points the way to technological advances

First developed in the late 1980s, lithium-ion batteries now power everything from tablet computers to power tools to electric cars. Despite tremendous progress in the last two decades in the engineering and manufacturing of lithium-ion batteries, they are currently unable to meet the energy and power demands of many new and emerging devices. This book sets the stage for the development of a new generation of higher-energy density, rechargeable lithium-ion batteries by advancing battery chemistry and identifying new electrode and electrolyte materials.

The first chapter of Lithium Batteries sets the foundation for the rest of the book with a brief account of the history of lithium-ion battery development. Next, the book covers such topics as:

• Advanced organic and ionic liquid electrolytes for battery applications
• Advanced cathode materials for lithium-ion batteries
• Metal fluorosulphates capable of doubling the energy density of lithium-ion batteries
• Efforts to develop lithium-air batteries
• Alternative anode rechargeable batteries such as magnesium and sodium anode systems

Each of the sixteen chapters has been contributed by one or more leading experts in electrochemistry and lithium battery technology. Their contributions are based on the latest published findings as well as their own firsthand laboratory experience. Figures throughout the book help readers understand the concepts underlying the latest efforts to advance the science of batteries and develop new materials. Readers will also find a bibliography at the end of each chapter to facilitate further research into individual topics.

Lithium Batteries provides electrochemistry students and researchers with a snapshot of current efforts to improve battery performance as well as the tools needed to advance their own research efforts.

CHAPTER 1

ELECTROCHEMICAL CELLS: BASICS

Hubert Gasteiger, Katharina Krischer, and Bruno Scrosati

1 ELECTROCHEMICAL CELLS AND ION TRANSPORT

2 CHEMICAL AND ELECTROCHEMICAL POTENTIAL

2.1 TEMPERATURE DEPENDENCE OF THE REVERSIBLE CELL VOLTAGE

2.2 CHEMICAL POTENTIAL

2.3 ELECTROCHEMICAL POTENTIAL

2.4 THE NERNST EQUATION

2.5 ELECTROCHEMICAL DOUBLE LAYER

3 OHMIC LOSSES AND ELECTRODE KINETICS

3.1 OHMIC POTENTIAL LOSSES

3.2 KINETIC OVERPOTENTIAL

3.3 THE BUTLER–VOLMER EQUATION

4 CONCLUDING REMARKS

BIBLIOGRAPHY

1 ELECTROCHEMICAL CELLS AND ION TRANSPORT

An electrochemical cell is a device with which electrical energy is converted into chemical energy, or vice versa. We can consider two types: electrolytic cells, in which electric energy is converted into chemical energy (corresponding to the charging of a battery), and galvanic cells, in which chemical energy is converted into electric energy (corresponding to a battery in discharge). In its most basic structure, an electrochemical cell is formed by two electrodes, one positive and one negative, separated by an ionically conductive and electronically insulating electrolyte, which may be a liquid, a liquid imbibed into a porous matrix, an ionomeric polymer, or a solid. At the negative electrode, an oxidation or anodic reaction occurs during discharge (e.g., the release of electrons and lithium ions from a graphite electrode: LiC6 → C6 + Li+ + e−), while the process is reversed during charge, when a reduction or cathodic reaction occurs at the negative electrode (e.g., C6 + Li+ + e− → LiC6). Even though the negative electrode is in principle an anode during discharge and a cathode during charge, the negative electrode is commonly referred to as an anode in the battery community (i.e., the discharge process is taken as the nominal defining process). Similarly, a reduction or cathodic reaction occurs at the positive electrode during discharge (e.g., the uptake of lithium ions and electrons by iron phosphate: FePO4 + Li+ + e− → LiFePO4), and thus the positive electrode is commonly referred to as a cathode, even though, of course, an anodic process occurs on the positive electrode during charge. Since this convention can be somewhat confusing, referring to the electrodes as a negative or positive electrode would elminate the ambiguity introduced by using the terms anode and cathode.

Figure 1 schematizes an HCl/H2/Cl2 electrolytic cell. The electrochemical processes are the cathodic reduction of hydrogen ions (protons) at the negative electrode (2H+ + 2e− → H2) and the anodic oxidation of the chloride ions at the positive electrode (2Cl− → Cl2 + 2e−). These two half-cell reactions can be added up to the overall reaction of this electrolytic cell: namely, the evolution of chlorine and hydrogen from hydrochloric acid (used industrially to recycle waste HCl in chemical plants): 2HCl → H2 + Cl2. As illustrated in Figure 1, an electrochemical reaction leads to a flow of electrons in the external circuit which is balanced by the migration of positive ions (cations) to the cathode and of negative ions (anions) to the anode; the principle of electroneutrality demands that the external electronic current must be matched by an internal ionic current (i.e., by the sum of the cation flow to the cathode and the anion flow to the anode).

FIGURE 1 Electrolytic cell, illustrating the decomposition of aqueous hydrochloric acid into hydrogen and chlorine. Here, aqueous HCl serves as an ionically conducting and electronically insulating electrolyte, facilitating the overall reaction: 2HCl → Cl2 + H2.

The reversible cell voltage, Ecell,rev, also referred to as the electromotoric force (emf), can be obtained from the Gibbs free energy change of the reaction,

:

(1)

where n is the number of electrons involved in the electrochemical reaction (for Fig. 1, n = 2) and F is the Faraday constant, equal to 96,485 As/mol. The standard Gibbs free energy of reaction,

, can readily be obtained from the standard Gibbs free energies of formation, ΔGf0, as i...

Table of contents

• Cover
• Series
• Title Page
• Copyright
• Contributors
• Preface
• Chapter 1: Electrochemical Cells: Basics
• Chapter 2: Lithium Batteries: from early stages to the future
• Chapter 3: Additives in Organic Electrolytes for Lithium Batteries
• Chapter 4: Electrolytes for Lithium-Ion Batteries with High-Voltage Cathodes
• Chapter 5: Core–Shell Structure Cathode Materials for Rechargeable Lithium Batteries
• Chapter 6: Problems and expectancy in Lithium Battery technologies
• Chapter 7: Fluorine-Based Polyanionic Compounds for High-Voltage Electrode Materials
• Chapter 8: Lithium–Air and Other Batteries Beyond Lithium-Ion Batteries
• Chapter 9: Aqueous Lithium–Air Systems
• Chapter 10: Polymer electrolytes for lithium–air batteries
• Chapter 11: Kinetics of the Oxygen Electrode in Lithium–Air Cells
• Chapter 12: Lithium-ion batteries and supercapacitors for use in hybrid electric vehicles
• Chapter 13: Li4Ti5O12 for High-Power, Long-Life, and Safe Lithium-Ion Batteries
• Chapter 14: Safe Lithiium Rechargeable Batteries Based On Ionic Liquids
• Chapter 15: Electrolytic Solutions for Rechargeable Magnesium Batteries
• Chapter 16: Rechargeable Sodium and Sodium-Ion Batteries
• Index
• The Electrochemical Society Series