Invented by LEE; Jin Hyon, PAIK; Un Gyu, SONG; Tae Seup, KIM; Ji Woon, KIM; Min Sung, CHO; Chae Woong

Let’s dive into a new and exciting patent about a special type of electrode for rechargeable lithium batteries. This isn’t just a small change – it could make batteries work better, last longer, and be safer, all thanks to a new way of making the part of the battery that holds and moves electricity. We’ll break down what’s happening in the world of batteries, what scientists already knew, and then what this invention brings to the table.

Background and Market Context

Batteries are everywhere. From phones and laptops to cars and even power tools, we rely on them daily. As our devices get smarter and more powerful, we want batteries that charge faster, last longer, and don’t break down. More people are using electric vehicles and bigger gadgets, so the need for better batteries keeps growing.

Right now, lithium-ion batteries rule the market. They are great because they can be recharged many times, have lots of energy in a small package, and don’t weigh much. This makes them perfect for things you carry, like phones, and for big things, like electric cars. But these batteries can have problems. They might wear out quickly, not hold enough charge, or even become unsafe if they get too hot or damaged.

One of the most important parts inside a battery is called the electrode. This is where the magic happens – it’s the place that stores energy and lets it flow when you need it. Most electrodes today are made using a “wet” process, where powders are mixed with liquids to form a paste. This paste is spread on a sheet and then dried. But this method uses chemicals that can be bad for the environment and cost a lot to handle safely. Plus, it can make batteries heavier and limit how much energy they can store.

To fix these problems, researchers have been working on “dry” electrode methods. This means making the electrode without those wet chemicals. It’s cleaner, cheaper, and can help make batteries that work even better. But making dry electrodes isn’t easy. It’s hard to get the powders to stick together and form a strong film that can handle lots of charging and discharging. If the film is too weak, the battery will break down faster. If it’s not conductive enough, the battery won’t deliver enough power.

This new patent tackles these challenges head-on. It focuses on a special kind of carbon, called porous carbon black, and a way to mix it with other powders to make a strong, efficient, and reliable electrode – all without the mess of wet chemicals. This could be a big step forward for the battery industry.

Scientific Rationale and Prior Art

Why is making a better electrode so tough? To answer that, we need to know what an electrode does and how it’s made. The electrode is a thin sheet inside the battery that helps move lithium ions back and forth as the battery charges and discharges. It’s made of three main things: an active material (where the energy is stored), a binder (which holds everything together), and a conductive additive (which helps electricity move easily).

Traditionally, the binder is a sticky chemical that helps glue all the powders together. In wet processes, the binder is dissolved in a solvent, mixed with other powders, and then spread onto a sheet. The solvent is then dried away, leaving a film. But the leftover binder can sometimes make it harder for electricity to flow, and the solvents can be bad for both the environment and workers.

With dry methods, there’s no solvent. The powders are just mixed together, and the binder is “fibrillated” – which means it’s stretched and pulled into tiny threads that help hold everything together. But without the liquid, getting the binder to stick well is much harder. If the binder doesn’t form lots of tiny fibers, the electrode won’t be strong enough, and parts of it might fall apart during use.

To help with this, scientists have tried different kinds of binders and conductive additives. Carbon black is a common choice for the conductive additive. It’s a fine black powder that helps electricity move through the electrode. But not all carbon black is the same. Some types have more surface area, and some have more pores (tiny holes). These differences can change how well the binder sticks and how well the electrode works.

Other patents and research have looked at using carbon black with different properties. Some have used carbon black with high surface areas to help the binder stick better. Others have tried mixing in other types of carbon, like nanotubes or fibers. But these methods still struggle to balance strength and conductivity, especially in dry electrodes. Sometimes the electrode is strong but doesn’t conduct well, or it conducts well but is too weak.

What’s new here is the focus on the pore size and surface area of the carbon black. This patent shows that by carefully controlling these features, you can make the binder form more fibers, which strengthens the electrode and makes it conduct better. The patent also covers a new way to make this special carbon black, by heat-treating it for just the right amount of time to get the best mix of surface area and pores.

This isn’t just about picking any carbon black off the shelf. The process in this patent creates a material that is super porous, with specific peaks in pore size that help the binder do its job better. No prior art describes this exact combination of features, especially in dry electrode films for lithium batteries. That’s what makes this invention stand out.

Invention Description and Key Innovations

Now, let’s look at what this patent actually claims and why it matters. The invention is all about making a “freestanding dry electrode film” for rechargeable lithium batteries. This film includes three main parts:

1. Electrode active material (the energy storage part),
2. Binder (the glue),
3. Conductive additive (the helper for electricity flow).

The big breakthrough is the use of a “porous carbon black-based compound” as the conductive additive. What’s special about this carbon black? It has a very high surface area – at least 600 square meters per gram. That means there’s a lot of space for things to stick to. Even more important, it has two main groups of pores: one set of tiny holes (1 to 10 nanometers wide) and one set of bigger holes (10 to 100 nanometers wide). When you plot this on a graph that shows how many pores there are at each size, you see two big peaks – this is unique.

This structure helps in two ways. The tiny pores give the binder lots of places to grab onto, which helps it form more fibers. The bigger pores make it easier for lithium ions to move through the electrode, which means faster charging and better performance. By having both types of pores, you get a film that is both strong and conducts electricity very well.

The patent also explains how to make this special carbon black. You start with a regular carbon black powder and heat it in a furnace at a temperature below 650 degrees Celsius, for up to 90 minutes. If you heat it for too long, the pores start to close up, and you lose the special structure. If you don’t heat it long enough, the pores don’t form as well. The process is carefully controlled to get just the right kind of porosity and surface area.

The binder used here is usually a type of plastic called PTFE (polytetrafluoroethylene), which is known for being tough and slippery. In this process, the PTFE is fibrillated – stretched into tiny threads that help hold the electrode together. The special carbon black helps this happen more easily, so you don’t need as much binder, keeping the electrode light and conductive.

The final electrode film is strong, thanks to the extra fibers, and it allows electricity and lithium ions to move easily. Tests show that batteries made with this electrode last longer, charge faster, and work better at high power. In side-by-side tests with regular carbon black (or with carbon black that was heated for too long or not at all), the new material performed much better. It had lower resistance, higher strength, and kept working well even after many cycles of charging and discharging.

What’s also important is that this process uses no solvents. This makes it cleaner, safer, and cheaper to make. There’s less risk of fire or pollution, and the whole manufacturing process is faster and simpler. This is a big deal for battery makers who want to scale up production and meet new environmental standards.

In summary, the key innovations in this patent are:

– Using a carbon black with a very high surface area and a special mix of pore sizes.

– Controlling the heat treatment to get just the right structure.

– Making a strong, conductive dry electrode film that works better than anything before.

– Doing all of this without solvents, making battery production safer and greener.

Conclusion

This new patent shows a smart way to make lithium battery electrodes that are stronger, more conductive, and easier to make. By carefully designing the carbon black additive and using a dry process, this invention solves big problems in battery manufacturing. It means batteries could last longer, charge faster, and be made with less impact on the environment. As the demand for better batteries keeps growing, inventions like this will be key to powering our future devices and vehicles. If you’re involved in battery research, manufacturing, or even just interested in green technology, keep an eye on this new approach – it could change the way batteries are made for years to come.

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