Nobel Lecture: John B. Goodenough, Nobel Prize in Chemistry 2019

TL;DR

Lithium-ion batteries produce electricity during discharge as lithium ions move internally from the anode to the cathode while electrons flow through an external circuit from a higher to a lower energy level. High voltage requires a low cathode energy level and a high anode energy level, but both must remain within the electrolyte bandgap to prevent internal electron leakage and short circuits.

Transcript

honorable laureates yours excellencies distinguished colleagues members of the Academy ladies and gentlemen this year's Nobel Prize in Chemistry is all about batteries and how to convert chemical energy provided in a very lightweight compact and high-capacity form into electricity and vice versa and by doing so creating a rechargeable world now the... Read More

Key Insights

• Lithium-ion batteries helped enable portable electronics by providing chemical energy in a lightweight, compact, high-capacity, and rechargeable form. Sony developed the lithium-ion battery system for the wireless revolution, supporting devices discussed in the lecture, including cell phones and laptops.
• Rechargeable battery development is a difficult systems problem because many components and requirements must work together in a suitable configuration. A successful design must address cost, stored electric power, energy density, voltage, current, ion transport, electron control, and safe operation.
• A lithium-ion cell has three major components: a negative electrode called the anode, a positive electrode called the cathode, and a polymeric separator soaked with liquid organic electrolyte. These components direct ions and electrons along different paths during charging and discharging.
• Charging moves lithium ions internally from the cathode to the anode while electrons travel from the cathode to the anode through an external circuit. The required energy is supplied as electricity from an electrical outlet, raising the electrons to a higher energy level.
• Discharging moves lithium ions internally from the anode to the cathode while electrons travel through the external circuit in the same overall direction. The electrons fall from a higher energy level at the anode to a lower level at the cathode, releasing usable electricity.
• The separator and electrolyte must conduct lithium ions while insulating against electrons. This separation forces electrons through the external circuit, where their energy can power a cell phone or drive an electric vehicle instead of leaking directly through the battery.
• Cell voltage is determined by the difference between the cathode and anode energy levels. Higher voltage requires the cathode level to be as low as possible and the anode level to be as high as possible, subject to the electrolyte’s stability limits.
• Electrode energy levels must remain within the electrolyte bandgap, bounded by its lowest unoccupied and highest occupied molecular orbitals. If an unsuitable level permits electrons to enter the electrolyte, internal leakage and a short circuit can result during charging.

Questions & Answers

Q: How does a lithium-ion battery generate electricity?

A lithium-ion battery generates electricity during discharge by moving lithium ions internally from the anode to the cathode while electrons travel from the anode to the cathode through an external circuit. The electrons move from a higher energy level at the anode to a lower energy level at the cathode. The released energy is extracted as electricity to power a cell phone or drive an electric vehicle.

Q: What are the main components of a lithium-ion battery?

A lithium-ion battery has three major components: a negative electrode called the anode, a positive electrode called the cathode, and a polymeric separator soaked with liquid organic electrolyte. The electrolyte and separator provide an internal path for lithium ions while blocking electrons. The external circuit, using conductors such as copper or aluminum wire, provides the separate path through which electrons move.

Q: What happens inside a lithium-ion battery during charging?

During charging, lithium ions move internally from the cathode to the anode. At the same time, electrons move from the cathode to the anode through the external circuit, with electricity supplied from an electrical outlet. The charging voltage slopes slightly upward because the energy difference between the cathode and anode levels increases as the charging process proceeds.

Q: What happens inside a lithium-ion battery during discharge?

During discharge, lithium ions move internally from the anode to the cathode, while electrons travel from the anode to the cathode through the external circuit. The electrons fall from a higher energy level to a lower one, releasing energy that can be used as electricity. The voltage slopes in the opposite direction from charging because the difference between the electrode energy levels decreases.

Q: Why must the separator block electrons in a lithium-ion battery?

The separator must block electrons so that charge moves internally only in the form of lithium ions. Electrons must instead pass through the external circuit, where their released energy becomes useful electricity. If electrons can leak through the electrolyte inside the cell, they bypass the intended circuit and may produce an internal short circuit rather than powering the connected device.

Q: How is lithium-ion battery voltage determined?

Lithium-ion battery voltage is determined by the difference between the cathode and anode energy levels. A larger voltage requires a cathode energy level that is as low as possible and an anode energy level that is as high as possible. Both levels must still fit within the electrolyte bandgap, so voltage cannot be increased without considering electrolyte stability and possible electron leakage.

Q: Why was the lithium cobalt oxide cathode important?

The lithium cobalt oxide cathode was important because it provided a high-voltage cathode and allowed the use of a carbon anode instead of a lithium anode, where dendrites could develop. Akira Yoshino recognized that the cathode material should be paired with a carbon anode. He demonstrated such a cell for Sony, which developed the system for the wireless revolution.

Q: How did Goodenough’s earlier oxide research support battery cathodes?

Goodenough’s work on transition-metal oxides extended from 1950 to 1980 and included magnetic materials for early computer memory, cooperative atomic orbital ordering, magnetic interactions, and solid sodium-ion electrolytes. His group also developed the NASICON structure, meaning sodium superionic conductor. These chemistry and physics studies established a foundation for developing oxide cathodes for lithium-ion batteries beginning in 1980.

Summary

The Nobel Prize in Chemistry for 2019 was awarded to John Goodenough, Stanley Whittingham, and Akira Yoshino for their contributions to the development of the modern lithium-ion battery. This breakthrough has revolutionized the way we live by powering mobile devices, electric vehicles, and renewable energy sources.

Questions & Answers

Q: What are the main challenges in developing efficient rechargeable batteries?

Developing efficient rechargeable batteries is a daunting and arduous task. It requires finding solutions to fit all the puzzle pieces together and create a good battery configuration. This is especially challenging for rechargeable batteries.

Q: How has the lithium-ion battery changed our world?

The lithium-ion battery has had a significant impact on our lives. It has been a major driver of the mobile revolution, allowing us to have access to our mobile devices wherever and whenever we need them. It has also facilitated the shift towards electric vehicles and has enabled the use of renewable energy sources. We can now access electricity without relying solely on the grid, which has dramatically changed the way we live.

Q: Who were the scientists involved in the discovery of lithium and the naming of the element?

Gustavus Magnus (Gus) and Johann Arfvedson discovered the element lithium almost 200 years ago on an island in the Stockholm archipelago. They proposed the name lithium, derived from the Greek word "lithos," meaning stone or rock.

Q: What is the significance of lithium-ion batteries in the mobile revolution?

Lithium-ion batteries have played a crucial role in the mobile revolution. They have powered portable electronic devices, such as cell phones and laptops, that have become an integral part of our daily lives.

Q: How are lithium-ion batteries transforming the transportation sector?

Lithium-ion batteries are increasingly used in electric vehicles, including large trucks and even aircraft. This shift towards electrically driven vehicles in the transportation sector is reducing our dependence on fossil fuels and contributing to a more sustainable future.

Q: How are lithium-ion batteries facilitating the use of renewable energy sources?

Lithium-ion batteries are being used as a complement to renewable energy sources, such as wind and solar energy. These renewable sources fluctuate over time, but with the help of lithium-ion batteries, we can store and access the electricity they generate whenever it is needed. This allows us to rely less on the traditional power grid and increases the use of renewable energy.

Q: Who is John Goodenough and what is his contribution to the development of the modern lithium-ion battery?

John Goodenough, born in 1922, is one of the recipients of the Nobel Prize in Chemistry for his contributions to the development of the modern lithium-ion battery. He is currently an active researcher at the University of Texas at Austin and continues to work on advancing lithium-ion battery technology.

Q: How does the lithium-ion battery work?

A lithium-ion battery consists of three major components: the negative electrode (anode), positive electrode (cathode), and a polymeric separator soaked with liquid organic electrolyte. During charging, lithium ions move from the cathode to the anode internally, while electrons move from the cathode to the anode through the external circuit to balance the charge. During discharging, the process is reversed, with lithium ions moving from the anode to the cathode and electrons flowing from the anode to the cathode through the external circuit.

Q: What factors need to be considered in designing a good battery?

Several factors need to be considered when designing a good battery. These include cost, energy density (the amount of electric power stored in the battery), power (the current times voltage), capacity, cycle life (the number of charge and discharge cycles a battery can withstand), and safety. Additionally, it is important to consider the environmental impact and the ability to recycle materials used in the battery.

Q: How do materials selection impact the performance of a battery?

The performance of a battery is heavily influenced by the materials used. Materials selection affects factors such as energy density, power, capacity, cycle life, and safety. Choosing the right materials is critical in designing a battery that meets the desired specifications and performance requirements.

Q: How are transition metal oxides important in the development of lithium-ion batteries?

Transition metal oxides play a crucial role in the development of lithium-ion batteries. They are used as cathode materials and can increase the voltage and energy density of the battery. The discovery of three classes of cathode materials by John Goodenough involved the study of transition metal oxides and their properties, laying the foundation for the practical implementation of lithium-ion batteries.

Takeaways

This year's Nobel Prize in Chemistry recognizes the groundbreaking contributions of John Goodenough, Stanley Whittingham, and Akira Yoshino in the development of the modern lithium-ion battery. Their discoveries have had far-reaching impacts on our daily lives, from powering our mobile devices to transforming the transportation and energy sectors. The development of efficient, safe, and renewable energy storage systems is crucial in reducing our reliance on fossil fuels and achieving a cleaner and more sustainable future. Interdisciplinary research and continuous advancements in battery technology will play a vital role in shaping the future of energy storage and ensuring a cleaner planet for future generations.

Summary & Key Takeaways

• The 2019 Nobel Prize in Chemistry recognized John Goodenough, Stanley Whittingham, and Akira Yoshino for discoveries leading to the modern lithium-ion battery. Their work helped create a rechargeable world by supporting portable electronics, electric vehicles, and storage that complements fluctuating renewable energy sources such as sunlight and wind.

• Goodenough’s earlier research on transition-metal oxides included magnetic materials for computer memory, cooperative atomic orbital ordering, magnetic interactions, and the NASICON sodium superionic conductor. This work combined physics and chemistry and established knowledge that later supported the development of oxide cathodes for lithium-ion batteries beginning in 1980.

• A lithium-ion battery contains an anode, cathode, and polymeric separator soaked with liquid organic electrolyte. During charging, lithium ions and electrons move toward the anode by different paths. During discharge, they return toward the cathode, and the electrons release usable energy while traveling through the external circuit.