The science inside lithium-ion batteries - with the Faraday Institution

Summary

Professor Lois Piper from WMG delves into the intricacies of lithium-ion battery technology, highlighting lithium's role as the lightest metal with the highest electrochemical potential for energy storage. The script explains the battery's key components, including the active materials, electrodes, and the process of lithium ion movement for energy storage and release. It also touches on current manufacturing challenges and potential improvements in electrode production and battery aging for enhanced performance and reduced environmental impact.

Takeaways

• 🔋 Lithium's Unique Properties: Lithium is the lightest and smallest metal with the highest electrochemical potential, which allows for high energy storage in terms of weight and volume.
• 🌐 Active Materials: The key components of a lithium-ion battery include layered oxide (cathode) and graphite (anode), which facilitate the movement of lithium ions and electrons.
• 🎨 Slurry Preparation: Active materials are mixed into a slurry, an ink-like substance, to ensure even distribution on metal foils.
• 📏 Metal Foils: The slurry is coated onto aluminum foil for the cathode and copper foil for the anode to create the electrodes.
• 🍔 Sandwich Structure: A separator is added between the electrodes to prevent a short circuit, forming a sandwich-like structure.
• 🔩 Cell Formats: Batteries can be assembled in various formats, such as cylindrical or pouch cells, which are common in mobile phones.
• 💧 Liquid Electrolyte: The battery is completed by adding a liquid electrolyte, which allows lithium ions to move between the electrodes.
• 🔄 Charging and Discharging: Energy storage and release involve the movement of lithium ions and electrons between the cathode and anode, forming and breaking bonds.
• 🛠️ Manufacturing Process: The process includes coating, drying, pressing, cutting, and stacking electrodes, followed by the addition of electrolyte and a formation cycle to activate the battery.
• 🚀 Future Improvements: Advancements in dry electrode manufacturing and more efficient battery formation and aging methods could significantly reduce the carbon footprint and improve performance and cost-effectiveness of lithium-ion batteries.
• 🚗 Electric Vehicle Applications: Battery packs, formed by connecting individual cells, are crucial for electric vehicles and other large-scale energy storage applications.

Q & A

What is the main topic discussed in the video transcript?

The main topic is the functioning and manufacturing process of lithium-ion batteries.

Who is the speaker in the video, and what is their position?

The speaker is Lois Piper, a professor of battery innovation at WMG.

Why is lithium considered important in lithium-ion batteries?

Lithium is the lightest and smallest metal with the highest electrochemical potential, enabling high energy storage in terms of weight and volume.

What are the key components of a lithium-ion battery mentioned in the transcript?

The key components are the layered oxide (source of lithium), graphite, positive electrode, negative electrode, separator, and liquid electrolyte.

How are the active materials used in a lithium-ion battery?

Active materials are made into a slurry (ink) and coated onto metal foils. The positive electrode is coated with metal oxide ink, and the negative electrode with graphite slurry.

What role does the separator play in a lithium-ion battery?

The separator physically separates the positive and negative electrodes to prevent a short circuit while allowing lithium ions to pass through.

Describe the formation process of a lithium-ion battery.

The battery components are assembled into formats like cylindrical cells or pouch cells, filled with liquid electrolyte, and then go through a formation cycle to activate the battery and ensure good interfaces between electrodes and electrolyte.

What improvements are suggested for lithium-ion battery manufacturing?

Improvements include developing dry electrode manufacturing to reduce carbon footprint and finding more efficient ways to form and age batteries to enhance performance and reduce costs.

How does the intercalation process work in a lithium-ion battery?

Intercalation involves lithium ions moving in and out of the anode and cathode materials, forming and breaking bonds to store and release energy.

What are the different formats for lithium-ion batteries mentioned, and where are they commonly used?

The formats mentioned are cylindrical cells, commonly used in various electronic devices, and pouch cells, often used in mobile phones.

Outlines

00:00

🔋 Understanding Lithium-Ion Battery Components and Operation

Professor Lois Piper from WMG discusses the fundamental aspects of lithium-ion batteries, emphasizing the importance of lithium's light weight and high electrochemical potential for energy storage. The key components include the active materials such as layered oxides and graphite, which facilitate the movement of lithium ions and electrons. The process involves creating a slurry from these materials, coating them onto metal foils to form electrodes, and then assembling them with a separator to prevent direct contact. The video script outlines the steps to create a functional battery, including the addition of a liquid electrolyte, which enables lithium movement between electrodes. The charging and discharging process is explained as the breaking and reforming of bonds within the electrodes, releasing chemical energy for various applications.

05:03

🚗 Enhancing Lithium-Ion Battery Production for Electric Vehicles

The script addresses the manufacturing considerations of current lithium-ion battery technology, highlighting areas for improvement to reduce the carbon footprint and enhance performance. It suggests that advancements in dry electrode manufacturing could significantly cut down energy expenditure and improve the environmental impact of battery production. Additionally, the script points out the need for more efficient methods of forming and aging batteries to boost their performance. The speaker anticipates that over the next decade, these developments could lead to substantial progress in both performance and cost reduction for lithium-ion batteries, which are crucial for electric vehicle applications.

Keywords

💡Lithium

Lithium is the lightest and smallest metal with the highest electrochemical potential, making it crucial for high energy storage in lithium-ion batteries. Its small size allows for efficient energy storage and release, which is essential for the battery's performance. The video emphasizes lithium's role in the battery's ability to store energy in terms of weight and volume.

💡Electrochemical potential

Electrochemical potential refers to the ability of a substance to undergo a chemical reaction that results in the movement of electrons, which is fundamental to the operation of batteries. In lithium-ion batteries, lithium's high electrochemical potential allows it to store and release a significant amount of energy, crucial for powering devices like phones and electric vehicles.

💡Layered oxide

Layered oxide is a type of material used in the positive electrode of lithium-ion batteries. It acts as a source of lithium ions, which are essential for the battery's operation. In the video, the layered oxide is mentioned as the starting point from which lithium ions are extracted and moved to the graphite electrode.

💡Graphite

Graphite is used in the negative electrode of lithium-ion batteries. It stores lithium ions during the charging process and releases them during discharging. The video describes how graphite works in conjunction with the layered oxide to facilitate the movement of lithium ions, contributing to the battery's ability to store and release energy.

💡Slurry

A slurry is a mixture of the active materials in a liquid form, which is then coated onto metal foils to create the electrodes of the battery. The video explains how these slurries are essential for evenly distributing active materials on the metal foils, ensuring efficient battery operation.

💡Separator

A separator is a physical barrier placed between the positive and negative electrodes to prevent short circuits while allowing lithium ions to pass through. The video mentions the separator's role in maintaining safety and functionality in the battery by keeping the electrodes apart.

💡Electrolyte

The electrolyte is a liquid that facilitates the movement of lithium ions between the electrodes. It is essential for the battery's operation, allowing ions to travel back and forth during charging and discharging. In the video, the electrolyte's addition is described as a critical step in forming the battery.

💡Intercalation

Intercalation refers to the reversible process of lithium ions moving in and out of the electrode materials during charging and discharging. The video explains how this process enables the storage and release of energy in lithium-ion batteries, highlighting its importance in the battery's functionality.

💡Formation cycle

The formation cycle is a slow initial charging process that activates the battery by ensuring good interfaces between the electrodes and the electrolyte. The video details this process as crucial for the battery's performance, as it helps to establish the necessary electrochemical pathways for efficient operation.

💡Battery packs

Battery packs are assemblies of multiple battery cells connected together to provide the required power for larger applications, such as electric vehicles. The video discusses how individual cells are combined into packs, emphasizing their role in delivering sufficient energy for high-demand uses.

Highlights

The key to the success of the lithium-ion battery is the lithium inside.

Lithium is the lightest and smallest metal with the highest electrochemical potential.

Lithium's properties translate into high energy storage in terms of weight and volume.

Active materials in a lithium-ion battery include layered oxide and graphite.

The layered oxide acts as a source of lithium, and graphite is used to store lithium.

Electrodes are coated with a slurry (ink) onto metal foils for good distribution of active materials.

Positive electrode is coated with metal oxide ink on aluminum foil.

Negative electrode is coated with graphite slurry on copper foil.

A separator is added to prevent short circuits by physically separating the electrodes.

Electrodes are rolled into different formats, such as cylindrical cells and pouch cells.

Lithium ions move between the electrodes through a liquid electrolyte.

Intercalation involves the reversible movement of lithium ions in and out of electrode structures.

During charging, lithium ions move from the cathode to the anode, forming new compounds.

Electrons travel around the circuit and rejoin lithium ions in new material phases in the anode.

Energy is released when lithium ions and electrons return to the cathode material.

Slurry is mixed in large vats and coated onto foils before being dried and collected as rolls.

Electrodes are cut and pressed to fit various battery formats like cylindrical cells.

Electrolyte is added, and a formation cycle ensures good interfaces between electrodes and electrolyte.

Formed cells are connected to create battery packs for electric vehicles.

Future improvements include reducing carbon footprint with dry electrode manufacturing.

More efficient formation and aging processes can enhance battery performance and reduce costs.

Transcripts

key to the success of the lithium ion

battery is the lithium

inside hi I'm Lois Piper I'm professor

of battery Innovation here at wmg and I

work on lithium ion battery

[Music]

research if we look at the periodic

table lithium is our lightest and

smallest metal with the highest

electrochemical potential this

translates into the ability to have high

energy storage in terms of weight and

volume volume so let's consider the key

components in a lithium ion battery well

first off we have to consider the active

materials so in this case what we have

is the layered oxide which also acts as

a source of lithium and we have the

graphite and the idea is we want to take

lithium from inside here and put it

inside the graphite and take advantage

of the electrons going on the outside

the only issue is this is still not a

battery so what we do is we make it into

a

slurry basically an ink

these inks are then coated onto metal

foils and the reason for that is to give

us a good distribution of the active

material onto our metal foils so here we

have the positive electrode where we

have coated that ink and dried it onto

an alumin fo so this is our metal oxide

which acts as our source as lithium on

the other side we have a negative

electrode where we coated the graphite

slurry and dried it on onto a copper

foil the idea is we want to connect this

together in a battery this is still not

the battery the issue we have here is

the concern that we generate a Shaw by

them touching we need to have that

physical separation so that's where we

add the

separator so we make a

sandwich and that

sandwich is then wrapped into different

formats so here we have our format for a

cylindrical cell which is something you

might be quite familiar with the idea is

then we take this rolled Swiss roll of

our electrode negative and positive

sandwich and place it into the casing

then we can add the liquid electrolyte

that allows the lithium to go back and

forth between the electrodes we also

have more pouch cell style and those

pouch styles are ones like in your

mobile phone and in those cases we can

view them as lasagna layers are

stoed so key components and our lithium

iron battery are essentially these

electrodes where we have our active

materials the idea is we're going to

break and reform Bonds in each of these

electrodes as a means of storing and

releasing energy when we charge up the

battery we're putting energy in and what

we're doing was taking Lithium ions from

the cathode material the positive

layered metal oxide they're going to

break from their electron and we're

going to have lithium ions go into the

bulk of the anode material and form a

new

compound and at the same time the

electrons are going to go around the

circuit and reform with them in new

material phases in the anode then when

we want to release that energy we're

going to have the reverse the lithium

and electrons moving in such a way that

they return back to the cathode material

and this is what we mean by intercation

the ability to reversibly and very

easily drive lithium in and out of a h

structure back and forth as a means of

generating new bonds and re breaking

those bonds to release chemical energy

that we use for driving our Technologies

such as phones laptops cars and

housesold

items so this is where we mix the

slurry so in these big fats here we make

a mix that mix is then translated

onto our coaters you can see the foils

that we coat

onto they then come through these

ovens and then we collect them as a roll

down

here and we then take it to calendar and

slitting instruments on this

side to cut or slit the electrodes to

fit the formats like cylindrical format

and then we also use these calendar rols

to squish the electrodes back to the

right density so once the electrodes

have been coated and dried and then

pressed after this stage they are cut

and stacked in the arrangements to suit

the

formats we then apply the addition of

electrolyte we go through what's known

as a formation cycle this is a slow

process to activate the battery by

ensuring good interfaces between the

electrode and the electrolyte and once

we've got that then when we have our

form cells these cells are then

connected together to form our battery

packs and packs are what we're

interested in with regards to our

electric

vehicles if we consider the

manufacturing considerations of current

lithium ion battery technology there's a

lot of things we can do to improve we

expend a lot of energy at the moment

using slurries where we have to drve

them to form the right sort of

electrodes so any progress in dry

electrod manufacturing will really help

with reducing the carbon footprint of L

iron battery production the second

component is if we can utilize more

efficient ways in which we can form and

age those batteries to improve

performance so these are two key areas

where in the next decade great strides

in terms of performance and cost

reduction could be achieved with those

developments