Chang-Hyeon Kim, Managing Director at JENAX, "Leads the Next Generation of Battery Production Without the Risk of Fire"

Published : Thursday, February 20, 2020, 3:23 pm
ACROFAN=Jae-Yong Ryu | | SNS
- With the continuous R&D, Jenax dominates both manufacturing technology and essential materials of a nonflammable battery.
- With the mass production of a remarkable flexible battery, Jenax leaps forward as a significant player in the industry.
- By securing battery manufacturing capabilities without worrying about fire, Jenax aims for smart devices, electric vehicles, and even the ESS market.

Lithium-ion batteries are being used as necessities in various electronic devices and infrastructures because they are suitable for the high energy capacity, lightweight, and miniaturization required in the IT industry. The lithium-ion battery is in the spotlight for next-generation energy. To be specific, the lithium-ion battery market, which was $33 billion in 2017, is expected to grow up to $160 billion in 2025 with an annual growth of 25%.

In the lithium-ion battery market, there are three product groups, namely LCO(LiCoO2), LFP (Li-FePO4), and NCM/NCA, all of which are named based on cathode materials. These materials have both pros and cons. For instance, cobalt is expensive as it is a rare metal, while steel is inexpensive but low in performance.

Lithium-ion batteries have become the mainstream by various attempts of the industry. However, subsequent fire accidents of ESS (Energy Storage System) have increased consumers’ anxiety and products’ safety controversy. Therefore, the key in the battery industry is to keep performance high and fire risk low.

Jenax Inc., a battery manufacturing company, is drawing attention by offering solutions that can improve battery safety based on its unique stainless steel wire processing capability. "We are confident that our proprietary battery manufacturing technology using metal fibers will significantly improve the performance and safety of batteries by using nonflammable electrolytes as well as secondary batteries, which use gel electrolytes,” said Chang-Hyeon Kim, managing director at Jenax. “Our new products that overcome fire risk will be the center of innovation for all industries where batteries are used in the global market."

▲ Chang-Hyeon Kim, Managing Director of New Business Development at Jenax

Q. What is the technical level and the status of the current battery market?

As of now, small cylindrical cell has the most advanced technology in the field of battery market. This is because the price is low, and the performance deviation of the products is minimal. Small cylindrical cell has a capacity of 1-2Ah, so when a fire breaks out, the explosion will relatively be small, and can be easily extinguished. On the other hand, the pouch type usually used in electric vehicles or ESS has more than 20Ah, so it is easy to detonate like a bomb when a fire occurs.

Q. Jenax has been listed on KOSDAQ as a stainless steel wire business, but why did the company decide its new business as a battery?

In 1991, we started the stainless steel wire business, which is similar to making conventional wires. The company was established with the aim of marketing ropes, automotive wire parts, and stainless steel welding rods by making and twisting wires. And we were listed on KOSDAQ in 2002.

In the early days after the establishment, various attempts were made to overcome competition issues with Chinese companies in the market. Just in case customers ever needed, we even colored stainless steel in gold, purple, white, etc. Then in the early 2000s, the nanomaterial boom broke out. At that time, we tried to manufacture very thin metal fibers out of wires like a hair or a thread. Only two companies in the world, one each in Belgium and Japan, had such metal fiber manufacturing technology at the time.

In this business, companies typically manufacture relatively thick stainless steel wire, such as 0.1mm, 0.05mm, and 0.03mm. However, only two companies had the technology to produce wires less than 10 ㎛ thick, which is almost one-tenth of the thickness of a hair. At that time the imported products with metal filters made from finely cut metal fibers were 100% sold. So, we thought that we could sell wires expensively if we produced them thinly. We continued our research and development ever since. It took us eight years to develop this metal fiber technology which we first announced in Korea in 2010.

▲ Jenax is a company that started with the stainless steel wire business, so its related know-how has found a new growth engine.

Q. So, Jenax has started a new business with the capabilities it has at the material level. If there was any critical factor that led the company to a new business, please introduce us.

Jenax is the first company to ever produce metal fiber in Korea and third in the world. In 2010, we tried to make and use metal filters. Since stainless steel can withstand temperatures of 1000 to 1500 degrees, it can be used as a filter to remove impurities at high temperatures in the polysilicon manufacturing process used as a solar power material. There was no suitable product in Korea, so all the products had to be imported.

Moreover, stainless steel is resistant to not only heat but also corrosion. As a variety of chemicals are used in petrochemical plants, corrosion is likely to occur, so the metal filters made from metal fibers were used instead of ordinary filters. And the metal filters had been imported from Belgium, so we thought that we could apply our products here.

Because stainless steel conducts electricity well, it is also used to make textile clothes that require good electrical conductivity. All of the antistatic wear worn by KEPCO employees in charge of telegraph poles are imported, so we intended to apply our products at the industrial textiles used for the uniforms. Metal fibers can also be used for weaving cloth, a material used for making fencing uniform. As stainless steel has a feature of blocking heat, the raw material of the thermal shielding curtain in front of the furnace of POSCO (Pohang Iron & Steel Co.) is made of stainless steel metal fiber.

To release various products using metal fibers, we had to be affiliated with a textile company, so we cooperated with Kolon, Woongjin Chemical and other companies for making prototypes. That was the moment we realized that this product can be used as a secondary battery.

At the end of 2010, Dr. Chul-Hwan Kim (Chief Director, KITE Entrepreneurship Foundation) filed a patent about applying metal fiber material to the electrode side of a rechargeable battery. He also succeeded in improving the charge/discharge rate and increasing the energy density. With the idea of making metal fiber materials into various forms of wires and flexible battery, he was looking for a company that seeks such material. Fortunately, he saw Jenax’s announcement, contacted us, and started to work together.

▲ Jenax is presenting an ideal model for Korean manufacturing by conducting perfect industry-educational cooperation.

Q. The first step began with the collaboration with experts. Then, how things worked out at the time of cooperation?

Dr. Chul-Hwan Kim contacted Jenax to obtain the metal fiber materials and test the materials.

When he made the electrode by sprinkling the electrode active materials onto the metal fiber and evaluated, it was confirmed that the capacity becomes larger than the battery using the aluminum foil form. Therefore, he asked to supply the material stably. It was the first time that the materials produced by Jenax could be also used in secondary batteries. The secondary battery has become a hot topic since we noticed that Jenax's metal fibers could be used to improve battery performance by placing electrode materials in a three-dimensional framework.

At that time, Dr. Chul-Hwan Kim was making a sell-off deal with LG Display about his business of electronic ink. He progressed the research by hoping that if he made a battery with the idea of a new secondary battery using metal fiber in the form of fiber, he would make a revolutionary performance improvement on the secondary battery.

Dr. Chul-Hwan Kim's original patent was transferred to Jenax. Three patents were filed between July and October 2010. In January 2011, we signed a memorandum of understanding (MOU) regarding the transfer of patent rights and decided to commercialize this patent technology at Jenax. Because the CEO of Jenax made a bold decision, things could go quickly.

▲ The flexible battery is expected to be commercialized in various forms with excellent performance and stability.

Q. Since when have you been working at Jenax? Please introduce us about the research and work that you have undertaken.

I joined on December 1, 2010, and worked as a director in patent verification and completion tasks. In order to make a battery using metal fiber, it is essential to find out which form of implementation would be appropriate, so I started the research on this first.

To study batteries in Korea, I thought it would be good to start at Daedeok Research Complex, which has a well-established research base. There was a team that researched batteries within ETRI (Korea Electronics and Telecommunications Research Institute), and my junior was on the team. So, I could conduct the tests with his help. I even transferred the technology developed by the team to complement technology.

I joined on December 1, 2010, and worked as a director in patent verification and completion tasks. In order to make a battery using metal fiber, it is essential to find out which form of implementation would be appropriate, so I started the research on this first.

To study batteries in Korea, I thought it would be good to start at Daedeok Research Complex, which has a well-established research base. There was a team that researched batteries within ETRI (Korea Electronics and Telecommunications Research Institute), and my junior was on the team. So, I could conduct the tests with his help. I even transferred the technology developed by the team to complement technology.

Since the first year was a period of getting direction, I had to find out what method to use for implementing as a real battery and how to use metal fiber material as a rechargeable battery. I mixed anode aluminum, cathode copper, separator, active material, and conductive material.

The electrons move to the current collector, and the lithium-ions move to the separator. A vital factor of battery performance is how fast lithium-ions and electrons move. The shorter the distance, the faster they move, and the better the battery's performance improves. The electrons go through the conductive material, so thickening the electrode will degrade performance. For example, how many times would it take to travel 50㎛ passing through 30㎚ sized conductive material particles? In this process, the resistance within the battery will be quite high.

However, for better battery performance, thinning the electrode to 50㎛ or less reduces its energy density. The energy density of the battery is closely related to the thickness of the electrode. Until this time, due to the battery performance, the electrode became thinner, and a lot of subsidiary materials that are not related to capacities such as separators and metal foils had to be used. Therefore, the energy density of the battery was low.

Nevertheless, if it is possible to make electrodes thick, move electrons fast, and maintain battery performance at the same time, you can use fewer subsidiary materials and increase energy density as a result. If you put metal fibers that conduct electricity very well in every corner of the active material and the electron produced by the active material gets on the metal fiber road right next to it, it will move quickly, resulting in a very low resistance of the electrode.

Q. How did you implement your ideas from the field in reality?

Metal fiber is in the form of a cotton ball. You first make the electrode into the positive and negative electrode by inserting the cathode active material, adding the separator, making the battery, and implementing the performance. At this time, there was a trial and error phase by studying how to insert the active material appropriately.

If the cotton ball is too thick, the travel distance of lithium-ion will be farther, and the performance of the battery will degrade. Therefore, we made various attempts to develop a way to make it thinner at the material level. We experimented with various temperature, pressure, size, and we even made it with just powder as the dry process. Then, we found that when electrode material was dispersed in a solvent using the wet process and applied to the metal fiber, it was evenly distributed on the metal fiber, which consequently showed a great performance. Since then, things got faster.

By applying the metal fiber, even if the electrode thickness is 2-3 times thicker than the existing system, it is confirmed that the battery can perform well. Even if the electrode thickness of 50㎛ thickens to 100~150㎛, it still performs well. By the way, I wondered if it would be thinner. In order to make the cotton ball thin, I thought that laying a thin sheet of short metal fibers would be the solution. I even tried to grind a cotton ball by using a kitchen mixer to make a fiber material in powder form and used it. This is how I obtained the fiber material in powder form. With this, I made the same electrode thickness and compared it, and as a result, the charge and discharge rate increased greatly.

The existing products typically require two hours to be fully charged. The metal fiber, in powder form with narrowed electrode, charged a battery at 70% in 12 minutes. In other words, a battery can be charged up to 20~30% in a single minute. The moment that can be called motivation for developing the material “metal powder” finally came.

▲ Jenax has realized things that existing batteries could not attempt to commercialize due to deterioration or threat of fire.

Q. We can say that you made the leap. What happened next?

I immediately found a way to mass-produce metal powder. I tried the idea of making it short and sprinkling it in an air-laid way. I also tried to disperse it in the solvent when making active materials.

With the metal fiber in the form of long-fiber, I tested to make it evenly re-absorb in a non-woven structure through the textile industry partners. In 2011 and 2012, I contacted a relevant institute, asked for permission to use their equipment, and started testing.

The uniformity of metal fibers into metal powder was achieved through the research conducted from September 2011 to the second half of 2012. In this uniformization process, quality management was a significant factor. In order to integrate with a rechargeable battery, the process must have been established stably.

I confirmed what kind of structure would be appropriate when the metal fiber is used as a rechargeable battery. I also researched how the battery performance improved at battery performance evaluation.

Q. Objectively, what level do you think Jenax is at now?

Even if the next generation of smartphones become smaller, Jenax would be able to fit a battery of the appropriate capacity in reduced size. Jenax also enables solution companies such as batteries and charging to gain the capability to run and utilize at lower power. All related patents are being filed and secured in-house.

Jenax solutions provide customized products according to customer needs. Whether it's energy density, fast charging, or discharging, Jenax can newly implement what you couldn't get in the past.

Q. There is an announcement that Jenax will directly mass-produce and sell flexible batteries. Please introduce us about the story related to this business.

Because metal fiber was used to make cloth, it has a steady performance even when physical bending force is applied. As a result of experiments in 2013, we softened the packing material and went through the steps of commercialization.

Basically, the electrode is in the form of a cloth. It's the same principle that, when we were playing in childhood, the mud got on our clothes and it didn't wash off. If you make a metal fiber into a form of cloth and add an active material, the particles will not fall no matter how much you bend. This is the basic theory of the flexible battery.

In the past, the active material was applied to the foil, so if it was bent by force, it fell. But when the active material was applied to the metal fiber, the active material, and the conductive particles did not fall off. Ensuring that the active material adheres well was the first challenge, and Jenax provided an answer with its own technology. The next step was the packaging. At first, we experimented with the snack pack, which is the softest among the materials that use aluminum, but it didn’t last long as it is not made for a rechargeable battery. Jenax has contacted a manufacturer with a technology to make a thin aluminum pouch and tested with them and completed commercialization by 2014.

▲ In the existing form of electron transference, there was a considerable limitation for product expansion.

▲ Jenax caught two birds, which are performance and safety, with the introduction of metal fiber.

Q. How do you plan to develop a flexible battery business?

At the beginning of the business, we thought of supplying metal fiber to rechargeable battery manufacturers, but, as the flexible battery was developed, the CEO of Jenax decided to run the business him/herself.

Since the battery business is like a comprehensive art, one good material cannot solve all the problems of a rechargeable battery. Nevertheless, the CEO has shown a strong commitment that we must do the flexible battery business. So, we started to manufacture the finished flexible battery products.

Jenax can apply its technology in the areas of EV, ESS, and flexible batteries by utilizing metal fiber materials with their exclusive technical capabilities. The plan is to start its own flexible battery business and ultimately achieve the finished battery products for the material business.

▲ Jenax flexible battery can be ideally applied for various electronic devices manufactured in a curved form.

Q. It's great to bend flexibly, but it's amazing that it won't catch fire even if you hit it with a hammer or a stone. Your expectation of the flexible battery must be high.

When consumers use flexible batteries, their biggest concern is fire from external shocks. It is important that the battery must be developed in the way it does not ignite and flares up even in dangerous situations. Jenax has implemented a technology that will never start a fire on a battery, even if it's pinned with a nail or taken into water or fire. Throughout the battery business, this technology has become a significant, and the performance based on this technology will appeal to customers.

Active materials, separators, and electrolytes used in finished product research must all be optimized at the design stage to become products that can be used by customers. You need to look at the general picture, including cell production and defect checking. Since early 2014, Jenax has faced many difficulties but made technological innovations with continuous R&D at the company-wide level. From 2015, we focused on flexible batteries and started research for mass production of finished products.

This finished product was presented to the world at the “CES 2015” exhibition and also presented at the “Wearable Expo Japan” in January of the same year. We took thousands of brochures to both exhibitions, but they were exhausted early. On top of that, the excited response from local companies has confirmed the potential and marketability of flexible batteries in the wearable device market. Not only the leading companies that have seen the actual products, but large Korean and Chinese companies are also showing great interest. We have joined the battery industry and market through conducting support projects for customers who have contacted us.

▲ Jenax flexible batteries have excellent physical properties that work even if wrinkled or folded. In addition, since the company has reduced the fire risk, it is expected to play an active role in the electric vehicle battery and ESS market.

Meanwhile, on January 29th, 2020, Jenax has announced that MyungSung TNS will be granted a patent co-license for rechargeable battery technology, and MyungSung TNS will pay a technology transfer fee for it. The two companies will accelerate their entry into the global EV battery market, starting with the supply of innovated LFP rechargeable batteries to the Chinese EV market. What’s more, they signed a memorandum of understanding (MOU) for the development of next-generation rechargeable battery technology and are speeding up the joint research.

Copyright © acrofan All Right Reserved

    Acrofan     |     Contact Us :     |     Contents API : RSS

Copyright © Acrofan All Right Reserved