Marisa Kuntanawong – ENTEC

Sunisa Buakeaw

Mon, 15 Nov 2021 05:27:57 +0000

Sunisa Buakeaw

Postdoctoral researcher

Education

Bachelor of Science (Second Class Honor 2014), Materials Science and Nanotechnology, Khon Kaen University, Thailand
Doctor of Science (2021), Materials Science and Nanotechnology, Khon Kaen University, Thailand

Expertise

Energy storage materials and technology
Fabrication & Characterization of Nanomaterials for Li-ion Batteries
Sn-based materials for energy storage: Li-ion battery and beyond lithium battery

Email:

sunisa.bua@ncr.nstda.or.th

Pidpong Janta

Mon, 15 Nov 2021 04:46:23 +0000

Pidpong Janta

Research Assistant

Education

Expertise

Email:

pidpong.jan@entec.or.th

Sareena Mhadmhan

Mon, 15 Nov 2021 04:28:57 +0000

Sareena Mhadmhan

Postdoctoral researcher

Education

Expertise

Email:

sareena.mha@ncr.nstda.or.th

Bowornchai Chareonteraboon

Mon, 15 Nov 2021 04:25:04 +0000

Bowornchai Chareonteraboon

Research Assistant

Education

Expertise

Email:

bowornchai.cha@entec.or.th

Chonnipa Puratane

Mon, 15 Nov 2021 04:17:01 +0000

Chonnipa Puratane

Research Assistant

Education

Expertise

Email:

chonnipa.pur@entec.or.th

Electric cars and energy storage technology

Tue, 21 Sep 2021 05:46:57 +0000

Interviewed by Dr. Buncha Thanaboonsombut

Thai Transcript by Mrs. Orawan Sumriddetkajorn

English translation by Ms. Patchareeya Rerkchavee

By Dr. Pimpa Limthongkul, Team Leader of Energy Storage Technology Research Team, Energy Innovation Research Group of ENTEC

Q: We have known that you had studied and researched on energy technology, especially the batteries, since you studied a Ph.D or before that and then came to work at MTEC. Could you tell us about your educational background?

A:

I’ve been working on batteries since 1997 and it was the first year of my Ph.D. in Materials Science department at MIT (Massachusetts Institute of Technology).

Q: At that time, what was the topic of your research study?

A:

In 1997, at that time, the most common batteries were single-use alkaline batteries or a very large cell phone battery. However, in 1992, it was the beginning of laptop computers which used lithium-ion batteries. The lithium-ion battery was very new at the time. Even in 1997, it had not been used in anything else other than mobile phones and laptops as portable electronic devices.

Q: As you work in a materials science, would you have to design systems, study various materials and batteries along with consult experts from other scientific disciplines?

A:

Most people usually think of batteries as an electrochemical system. The most familiar one, for an example, is the lead-acid batteries used in cars. However, the materials used in energy storage do not have to be liquid, but they could be a wide range of materials. Even the lithium-ion batteries also employ a variety of materials as well.
Although it is called lithium-ion, there are various materials in the system itself, such as carbon and lithium-storage agents. For example, Professor Yoshino [1] at Sony who had invented the storage of lithium in carbon, thus initiating a widespread use of lithium-ion batteries, which won him the Nobel Prize in Chemistry in 2019. However, the anode is also another material, a type of oxide compound invented by two other Nobel laureates, John Goodenough [2] and Professor Whittingham [3].

At that time, I was a scholarship student majoring in materials science and had been assigned to study ceramics. So I had to study the materials, especially ceramics, related to batteries. It is a variety of inorganic substances in batteries that can be used to store electrical charges.

Q: Since at that time, this technology was very new, so when you returned to Thailand, it would be quite difficult because our industry were not ready. How did you adapt yourself? Or how did you apply your knowledge to guide the direction of the development of battery energy storage systems?

A:

I studied for 5 years and returned to Thailand in 2002. At that time, there was virtually no battery research in Thailand because the research would require a lot of instruments. Therefore, we decided to collaborate with foreign partners and later we worked with various companies. At the end of my study, there was a company called A123 Systems established by my advisor and his team. We had made cathode materials and launched a startup company at MIT, which still operates today. Later, we worked with the company and learned basic knowledge from professors of MIT. In 2002, Thailand had very few investors, therefore, it was very difficult to get funding from private companies. I remembered that my first fund was 200,000 baht, which I had spent half of a total fund on a scale. So the rest of the money wasn’t enough to buy other equipment, as well as I couldn’t hide other people. Thus, I had to do it all by myself together with collaborating with the professors, in which sometimes I went to his lab to work. I also helped develop the part of an energy system and the fuel cell part for my leader, Dr. Sumittra Charojrochkul[4], by developing materials for solid oxide fuel cells.

[4] Sumittra Charojrochkul, Director of Energy Innovation Research Group of ENTEC

Q: Is it an application of your knowledge with closely-related subjects?

A:

Yes, it is. It actually employs the same basic knowledge, but depending on what systems you want to focus, all can be applied.

Q: Well, could it be said that you were the one who set up the infrastructure in the early stage and were the key person in technology, as well as built connections with foreign partners, especially the United States?

A:

I’m not sure, but all I could say is that I was the only one who had worked on lithium-ion battery when I came back. I’m also the one who set up cell production at the lab at MIT with my advisor. I did everything on my own starting from creating tools, a tester, cells by studying from the research paper until I was able to teach others.

Q: All of which must be considered beneficial for both MIT and Thailand because the system was set up from scratch?

A:

Yes, it was. It was quite difficult. We had learnt everything because no one had experience in those days. That is to say, there were no course on the science of batteries. So we couldn’t find anyone to teach us how to assemble the cells. At that time, there were only a few company selling testing equipment. In China, Research in this area had not yet begun. We didn’t get funding to purchase the tools because my advisor hadn’t been recognized as an expert in this field yet. However, he is very famous now because he had set up about 4-5 companies and 4 of them are energy companies.

Q: It normally takes time to build a team. How did you train people who didn’t have direct background for this field? And how did you work with other researchers and research assistants to create a team working on batteries?

A:

Actually, there are many people who have background in the field of fuel cell. In the beginning, Thailand had sent quite a number of people to study fuel cell technology. The knowledge of fuel cell could be easily adapted to be used in battery technology and vice versa. Sometimes, people ask whether our work would be obsolete if fuel cell became trendy. But we think we could catch up later. If fuel cells becomes more and more important, we still have people who have good background on its technology. They could perform materials characterization and share the information obtained.

I would like to add a few notes here. Right now, we have 4 or 5 new researchers at ENTEC who graduated in the battery field. I also train our assistants to work as a team. That is, there are always at least 2 researchers in a project, and both do not have expertise in the same field. For example, one with background in organic chemistry are paired with the other who has background in inorganic chemistry. One with expertise in mechanical design are paired with one who has background in electrical engineering. If a project’s main focus is on organic electrolyte, then a researcher in this field will lead and the other with inorganic chemistry will support. They will learn the system together because we can’t look at battery as a single or stand-alone material. A battery must be view as a system.

Therefore, the advantage of our team at NSTDA is that we have people who have knowledge in many disciplines working as a team, sharing ideas and discussing regularly.

Q: Let me ask you about the electric vehicles – what are the conditions that would encourage people to buy electric vehicles?

A:

Users would consider many aspects when buying electric vehicles. The most important ones are its price and ease of maintenance. Most of them would prefer the service center to be nearby and the infrastructure to be reliable, for example, support in case that their car is broken in the middle of the road. However, I would like to stress that the rise of electric vehicles must start with acceptable price for other aspects, such as reliability, could be supported by technology.

The battery price has dropped very fast, about 3 times lower compared to that of 10 years ago. We have seen the cost curve coming down quite a lot over the past few years. Changes happen quite fast. If we look back on the news about automobiles 3 years ago, we will see that it is different from the situation today.

Q: How far can electric cars go on one charge?

A:

As for a pure electric vehicle with no engine, it can travel about 300-500 kilometers on a single charge. A person living in Bangkok drives 40 kilometers per day on average, so this is OK. But if one drives to other provinces, such as Chiangmai which is about 700 kilometers from Bangkok, there must be charging points provided on the way. Also, there might be some concerns not only about the charging point but also about the charging time because it might take a couple of times to charge the battery and each time would take half an hour, which is longer than filling up with petrol which takes only 2 minutes. However, there is a fast-charging system which might take 15 minutes and can drive for 100-200 kilometers. All these issues are of interest to be communicated by the technologists.

Q: Is it possible to increase the battery capacity so that the electric vehicle could travel more than 300-500 km?

A:

The battery capacity depends on the weight and size of the vehicle that is able to support the amount of battery cells. The more number of cells, the greater the distance, but the weight and price will be higher as well. Therefore, when designing a car, one need to look at the requirements, the price that the customer is willing to pay, the weight of the car that must be carried over the time as well as the energy efficiency.

Q: Does the government or the industry have a policy to increase the number of charging stations in order to boost up the confidence in using electric vehicles?

A:

Well, the charging station is like a chicken-and-egg problem. If there were a lot of electric vehicles, there would be a lot of charging stations as well. In fact, there is a plan to install 1,000 charging stations around the country, including fast charging stations. As for highways, if the filling station were replaced by charging station or providing charging service, then the users would be more confident.

However, charging at home would not be a problem, but for charging at hotels would require infrastructure or being specified in the building code for the construction of a hotel or condominium. For example, newly-constructed houses everywhere in England are required by law to possess the charging system. In Thailand, the committee of the National Automobile Industry, an authority in charge of the transition to electric vehicle industry, is now considering about the charging stations.

Q: Has the plan been approved yet? If not, when it will be released?

A:

Not yet, we are working on it right now but the plan should be released around the end of 2021. I would say we are not the ultimate decision makers, but as a part of the working group, we are hoping that within this year the decision will be made since the situations are rapidly changing. Therefore, if our plans were to delay, we would have to keep updating and take appropriate actions, otherwise we might lose a huge opportunity.

Q: If one looks at Tesla, which focuses on producing luxury cars for high-end customers, and then expanding its business by building a battery factory because batteries are the core component of electric cars. As for China which champions the use of electric cars, it has a policy to transform an entire city from using combustion engine cars to electric vehicles. These two strategic model seems to be quite opposite. For Thailand, what kind of model would we use?

A:

This is all about the vision of the new s-curve industry, that is to focus on the big goals. Tesla wants to build electric vehicles because they believe that electric vehicles will be the future. However, Tesla was not the first brand to build electric car because there are many companies that has made them ages ago even the cost curve of the battery was not down and the technology is not yet mature.

Tesla waited until the cost of batteries dropped. The company started building a high-end electric vehicle model because it can deliver high torque and have an acceleration at a level of racing cars and thus can be sold with a high price. However, people don’t see it as necessary since it’s not the only type of car in the market, as well as it doesn’t have enough reliability in case that the car couldn’t be use. All in all, Tesla did intend to build electric vehicles.

In China, the electric vehicle industry has emerged from the fact that batteries are safer and more reliable. Because in the past, when the battery was not considered safe enough, it couldn’t be used in the car. The industry had to wait until the scientists who has got Nobel prizes had figured out the ways to make batteries become safer. Apart from being safe, batteries also have more capacity and are cheaper, therefore, the development of various materials for battery has initiated the electric vehicles industry.

The first 10 years (1992-2002) after I graduated, the battery employed lithium cobalt oxide (LCO), which was the only cathode material that could release high energy. However, since this material was very dangerous, it was then used at a small level. Later, there were various materials, such as lithium iron phosphate (LFP), lithium-ion manganese oxide (LMO), and lithium nickel manganese oxide (LNMO), all of which were safer and people have been assured to put them in cars.

For example, BYD (BYD Auto Co., Ltd.), one of the first company in China that manufacture electric cars, first started producing electric buses and then began to produce an electric taxi, which we used at Suvarnabhumi Airport. The company started its production using LFP and was at first being an OEM (Original Equipment Manufacturer) for other companies. However, in the end, the company decided to switch from battery company to car manufacturing company. That is, the company had started in different ways compared to Tesla. Tesla saw itself as an automotive maker and then bought the battery, and later started to design a battery pack to put in the car. On the other hand, BYD had started from producing the battery first and then transformed itself to be a car manufacturer.

To stress this point, Tesla itself said that its competitors are not car companies, but Apple and Google. The creation of a new industry from automotive industry. In the future, the important things will be digitization, the management of the entire network, as well as the energy issue, all these will change very quickly in the automotive industry.

Q: Do you have any comments on hybrid cars? As some companies view electric vehicles as an end-point, but during the transition of 5-10 years, they place importance on hybrid vehicles since the infrastructure is not yet ready?

A:

Thailand also supports the production of hybrid cars as well such as we have tax incentives. In the past, use of hybrid vehicles were considered a transition. Hybrid vehicles are primarily used for environmental reasons. That is, it helps reduce overall emissions, thus creating a good EURO efficiency, which is a mandate or requirement of European countries and the United States that prefer low carbon emissions. Therefore, hybrid cars can help; but back then, people didn’t expect that the battery price would go down very quickly and at the same time, the development of batteries was quite fast.
Hugh efforts has been put into research and development around the world in order to rapidly reduce the battery’s prices and increase its efficiency. In the beginning, there were not many players, but now when China starts to penetrate the market, it becomes a global leader in the electric vehicle industry. Chinese companies could be set up very easily since China has the entire value chain within the country. That is, a new industry can be created in a few years.

Q: Therefore, the transition period for hybrid vehicles in the market should be shorter due to the fast development of batteries, of which the technologies is better, higher capacity, and lower price?

A:

Yes, in the end, hybrids will be more expensive than pure electric vehicle since they have both the internal combustion engine and the battery system. Possessing two systems are not economically viable. Battery prices have dropped dramatically because of research and development, and rapid market building. Creating demand was done by various governments, such as those of Europe or China, thus creating an economy of scale. This will lead to lower battery prices and the price of electric cars has been dropping faster than people had expected.

Q: What is the role of the Energy Storage Technology Research Team in the electric vehicle value chain?

A:

We are technologists at the National Energy Technology Center, so our main responsibility is to work on research and development in the value chain focusing on energy storage systems. Our focus would be battery or super capacitor, or in the future, may be a hydrogen storage system, and other technologies related to energy storage system.

The battery prototype for electric vehicles

However, it is inevitable that we have to work with the industrial sector. As a group of people with expertise in this area, we need to provide policy recommendations for some works, and will also have some projects in this area to help the government in education or integrate technology into applications. For example, in our team, there is a group of Dr. Jiravan [5] whose work is to integrate renewable energy, such as solar power systems, into energy system and microgrid systems. A cost-effective use of batteries must be considered . The research team understands the performance and cost and always take these issues into account. However, in order to be more confident that we have considered all important aspects, for some projects we also works with competent partners such as TDRI (Thailand Development Research institute) on economics.

[5] Dr. Jiravan Mongkoltanatas, Researcher of Energy Storage Technology Research Team

Q: Well, you are also the President of Thailand Energy Storage Technology Association (TESTA). Could you tell us about TESTA?

A:

Thailand Energy Storage Technology Association (TESTA) has been established this year (2021). However, the Thai Energy Storage Technology Network Partners was established last year since we need quite a lot of people to do a lot of things. Eventually we had gathered from network partners as a collaboration between the National Science Technology Development Agency (NSTDA), King Mongkut’s University of Technology Thonburi, Khon Kaen University, King Mongkut’s University of Technology North Bangkok, and the Electric Vehicle Association of Thailand (EVAT).

Currently, there is quite a strong push on the electric vehicle industry and the battery usage has attracted a lot of attention in Thailand. Therefore, we should work together in order to exchange knowledge by providing useful and reliable information to the general public and be able to make a decision on usage or investment of various technologies. As a result, we had registered as an association, which was established on January 25th, 2021. We want it to be a common platform where we can talk, exchange, and understand the information. We expect to perform as an intermediary to send this information to various agencies or be able to exchange information among those interested people in this field, as well as keep the information up to date.

Q: As you have told us, it can be seen that Thailand has an industry, a national policy, and ENTEC that focuses primarily on research and development, as well as other energy-related issues. At the same time, does TESTA perform as a center for all stakeholders to share their policies?

A:

It is our vision and mission. We want TESTA to be the center of knowledge exchange and dissemination of useful information, and some are also providing information at the government level not from the academics. As we are technologists, we would like to understand the industry perspective on the problem. Because our research problem should not be of blue-sky type but must be a real-life problem or practical engineering that could also lead to a deep science. Therefore, technologists have a responsibility to help each other monitor the user as a contributor, and the manufacturer as the information provider of the problems, as well as responsible for helping to fill this gap together.

The audience can be assured that ENTEC have strong technical expertise that comes from research and development in collaboration with the manufacturing sector. Both TESTA and ENTEC are working to make the public be aware of the movements of the status and the different directions that are taking place, which can be considered to answer the needs of many levels, such as in-depth research and development, policy and others.

Well, we are willing to help each other. When it comes to energy, we are a part of ENTEC, we always see energy as an important factor in our lives. I’m glad to have the opportunity to work in many aspects for the maximum benefit to society, Dr. Pimpa said.

Lastly, we would like to thank Dr. Pimpa Limthongkul for sharing knowledge of Electric cars and energy storage technology and if there will be an opportunity in the future, we would like to invite her to share and discuss some in-depth aspects or other interesting issues. For the next episode, there will be researchers from ENTEC to provide information on various dimensions.

For those who are interested in this podcast, please visit:

ENTEC had joined an online seminar “Opportunities and Challenges of science, research, and innovation in driving Thailand to become the production center of ASEAN’s electric vehicle technology by 2025”

Mon, 30 Aug 2021 05:17:30 +0000

On August 25, 2021, the National Energy Technology Center (ENTEC) had joined an online seminar “Opportunities and Challenges of science, research, and innovation in driving Thailand to become the production center of ASEAN’s electric vehicle technology by 2025” under “The Knowledge Management Project for the system development of science, research, and innovation of the modern vehicles” organized by Thailand Science Research and Innovation (TSRI).

In this online seminar, there were the electric vehicle technology experts, namely, Mr. Chanyuth Chayawattana, Deputy Chief Executive Officer of Energy Absolute Public Company Limited, Mrs. Rosaya Teinwan, Executive Vice President-Business Development of Global Power Synergy Public Company Limited, Dr. Vikram Ahuya, Managing Director of Edison Motors Company Limited, Dr. Pimpa Limthongkul, President of Thailand Energy Storage Technology Association (TESTA), Dr. Ekkarut Viyanit, Principle Researcher of the National Science and Technology Development Agency (NSTDA), and Dr. Nuwong Chollacoop, Principle Researcher of the National Energy Technology Center (ENTEC), with Dr. Jakapong Pongthanaisawan, Chulalongkorn University, was the moderator.

Everything You Need to Know about Batteries

Mon, 19 Jul 2021 07:24:58 +0000

By Mr. Ukrit Sahapatsombut, Dr. Thanya Phraewphipat, Dr. Jiravan Mongkoltanatas, Dr. Priew Eiamlamai,
Dr. Nattanai Kunanusont, and Dr. Pimpa Limthongkul

Energy Storage Technology Research Team,
Energy Innovation Research Group of the National Energy Technology Center (ENTEC)

Overview

Q: What types of batteries are in use today? And what are the differences?

A:

Batteries in use today are divided into two main types:

1) Single-use batteries or primary batteries.

2) Rechargeable batteries or secondary batteries.

All batteries operate through electrochemical reactions called oxidation and reduction. Oxidation occurs at the anode. Reduction occurs at the cathode. In a single-use battery, these reactions are irreversible; whereas in a rechargeable battery, these reactions are reversible.

Q: What types of rechargeable batteries are in use today? And what are the differences?

A:

There are a dozen of rechargeable batteries but only a few are widely used, such as lead-acid batteries, nickel-metal hybrid batteries, lithium-Ion batteries, sodium-sulfur batteries, and batteries with the flow of energy storage as shown in Figure1.

Table1: Batteries in use today

Q: What is the direction of the development for each type of battery?

A:

In general, the aim of battery development is to achieve higher energy density (either per weight or per volume), improved safety performance, and lower price. According to Figure 1, it can be seen that the direction of battery technology is to develop higher energy density and specific energy; some examples shown are lithium-sulfur battery, lithium-air battery, zinc battery, aluminum battery, and solid lithium-ion battery. [1]

In addition, the development also includes materials improvement, such as anode material, cathode material, and electrolyte solution (especially in lithium-ion batteries that have higher electrical energy and power), as well as an increase in the range of operating temperatures.

Q: Is it OK to use a mobile phone while charging the battery? Why?

A:

Using mobile phones while charging is possible but not recommended. [2] The reason is that using and charging a mobile phone at the same time from a household electrical power (220V) power may result in danger from an electric shock or a leakage. Not only this danger comes from mobile phones or batteries, but also they can be caused by other electrical appliances in the house depending on the quality of the equipment and preventive measures.

The reasons that a user can get an electrical shock from a mobile phone while charging are as follows:

1. The charger is defected or has low quality. The function of a charger (adapter) is to convert an alternating current (AC) of 220V into a direct current (DC) with a voltage of no greater than 5V and protect the user from getting the AC power directly. However, if the charger is defected, it may create an electrical leakage.

2. The charging cable has low quality. The charging cable that has been in use for quite a while may be torn or broken, increasing a chance for leakage and burning risk.

Therefore, using a mobile phone while charging with a household electrical power (220V) power may not be safe. However, if it is necessary, using a power bank is a better choice.

In addition, using a mobile phone while charging may affect the battery lifespan due to extra heat generated. Thus, the user should avoid using the battery while charging to preserve the battery

Q: How does the charging affect the battery lifespan? What is the correct way to charge the battery?

A:

There are various types of batteries, each has its own characteristics and should be treated appropriately.
A lead-acid battery should always be kept in a fully charged condition.

A nickel-cadmium battery and a nickel-metal hydride battery, should not be frequently charged but should be used until fully discharged and then recharged to its full capacity.

A lithium-ion battery should be charged with a constant current. In some devices, when the battery is nearly fulled (>80-90%), the regulator will reduce the electric current by charging with constant voltage until the battery is fully charged. However, in theory, the optimum operating range to extend the lifespan of lithium-ion batteries is 20-80%. Therefore, if the users want to extend its lifespan, the following issues are noted.

A lithium-ion battery should not be used until it runs out because it will deteriorate faster.
Charging a lithium-ion battery overnight normally does not affect its lifespan significantly; however, this also depends on the device and charging system used
A fully-charged lithium-ion battery that has been left unused for a long time will deteriorate itself faster. Therefore, if not using, it should be charged halfway. However, if using the battery regularly, it can be fully charged in an appropriate way.
A lithium-ion battery should not be charged and used simultaneously.

Most importantly, the factors that affect battery lifespan, in general, are temperature, electric current, and charging voltage. Some recommendations for preserving the battery charging are as follows.

Choosing the right charger for the battery, e.g., a charger that has been approved to use with a particular device.
Do not use encapsulated gadgets (such as cell phone cases) that trap heat while charging and the device should not be placed in an enclosed or unventilated area.
Do not charge the battery in a high temperature location.

Q: What are the signs of battery deterioration?

A:

The hours of battery life decreases.
Battery deterioration means the battery’s capacity decreases and less power is available for a fully-charged battery. That is to say, a fully charged battery has a shorter lifetime for a similar task.
The heat of the battery increases.
Once the battery deteriorates, the internal resistance of the battery will increase. That is, more heat will be generated compared to that of the new battery, and the user will feel the heat (e.g., while using a mobile phone).
The battery behaves differently.
When the chemicals or materials inside the battery deteriorate, it may cause an accumulation of gases inside the battery, resulting in a swollen battery with a possible leakage of electrolyte.

Q: What makes the battery degrade? How to prevent it? Are the viscous liquids dangerous, especially when they touch the skin or wound?

A:

Battery deterioration is caused by chemical deterioration within the battery cells that decreases the battery’s capacity. Therefore, less power could be used for a fully charged battery. Some possible causes of battery deterioration are as follows:

An expiration of the chemicals or materials inside a battery cell.
An improper use and storage, which generate heat, a most influential factor that accelerate the deterioration of the battery.
A malfunction caused by undercharging or overcharging.

Thus, a practical preventive measure is to regularly inspect and check the charging system and examine the outside conditions and the leakage of the battery cell. In addition, a battery should not be stored or used in high temperatures since the battery lifespan will be reduced.[3]

The viscous liquids commonly seen leaking out from the carbon-zinc cell and alkaline cell are electrolytes. Typical batteries use ammonium chloride (NH4Cl) and zinc chloride (ZnCl2) as electrolytes. When manganese dioxide is completely reacted (the battery runs out), the acidic electrolyte will be able to react chemically with the zinc canister, which causes corrosion and leakage of internal chemicals. As for alkaline batteries, a potassium hydroxide solution is used as a basic electrolyte solution that can also react chemically with zinc containers when the battery has reached the end of its lifespan. Apart from the solution leakage, heavy metals were also found as shown in figure 2. An electrolyte of lithium-ion batteries is in liquid state and consists of lithium salts carbonate organic solvents. It can be deteriorated by moisture or heat, thus resulting in leakage occurs.

When an electrolyte is in contact with water or external moisture, it forms hydrofluoric acid (HF) with severely corrosive and highly toxic properties and can cause irritation. This acid can damage tissues and interfere with the function of the nervous system so that people who are in contact with this acid may not feel any pain at first, but in the long run, it will lead to osteoporosis and osteoarthritis. Thus, this acid is extremely detrimental.

Q: Does putting a battery in a freezer help extend the battery lifespan somehow?

A:

Putting a battery in a freezer in the hope of extending its lifespan is a misunderstanding because the freezer has a very low temperature, which may cause various terminals to deteriorate. That is to say, the battery should be kept at a temperature that is neither too high nor too low. However, once the battery is swollen or deteriorated, it should not be used but be replaced with a new battery.

Q: What is the memory effect in the battery? In what types of batteries this effect be found? How does it affect battery performance?

A:

The reason why certain batteries have a memory effect or unwanted “memory” is that there is a change in the microstructures of the positive and negative terminals that have not been used for a long time. This effect is found in nickel batteries, such as nickel-cadmium or nickel-metal hydride. In general, the crystal size of nickel compounds that collects the electric charge is small, thus creating a large surface area to conduct the electricity. However, if a part of the battery is left unused, the crystal size will increase, and the terminals’ overall surface will decrease, as well as the electrical resistance will increase and the reaction becomes more difficult, leading to the deterioration of the battery performance.

To avoid a memory effect, nickel batteries should not be charged and used at the same time but it should be used until it runs out or drains at least once a month to keep the crystal size of the nickel compound in the anode close to that of the original. The most widely used solution relies on a device that can draw an electric current until the battery has an electric potential lower than usual or 0.4-0.6 volts per cell to allow the large crystal forming at the pole to split and become smaller.

Currently, Sanyo/Panasonic (Sanyo SMI-Thailand Co., Ltd.) has succeeded in reducing the memory effect in Ni-MH batteries under the brand ‘Eneloop’.

Q: What are the reasons that may cause a battery to explode or catch fire?

A:

Various incidents may result in battery explosion and are grouped as follows.

1. A battery explodes or catches fire from external factors.
  1.1 It is overheated (thermal abuse).
  1.2 It is impacted by external shocks (mechanical abuse), such as being dropped or crushed, or impacted from a collision.
2. A battery explodes or catches fire from internal factors.
3. A battery management system has malfunctioned (BMS malfunction).
4. A battery is overcharged (charger malfunction).
5. An internal short circuit due to false design or the degradation of a battery.

These factors create internal heat and chemical reactions, leading to swollen, or exploded batteries if they cannot be cooled or released the gas. In order to prevent heat and high-pressure situations, most batteries should have expansion valves as a primary protection device. In addition, for lithium batteries with high-energy capacity, it is necessary to have protection devices preventing over-charged and over-discharged of the limited current and voltage.

There are two types of protection devices:

Protection Circuit Module (PCM) to prevent an overcharge and overuse of the battery by terminating the electricity when the battery reaches the specified voltage level.
Battery Management System (BMS) is a system, which controls and prevents the battery from working in danger, such as overcharging or discharging batteries, as well as balancing cell batteries to maximize battery capacity and extend its lifespan.

Q: What type of battery is a power bank? Why is it forbidden to carry on a plane if the capacity is larger than 32,000 mAh?

A:

A power bank contains lithium-ion batteries, which is forbidden to carry on a plane because it has a high energy-to-weight capacity. The International Air Transport Association (IATA) [4], therefore, has specified the rules and regulations of power bank batteries as follows.

Do not put power bank batteries in checked luggage.
The power bank batteries are allowed to carry a carry-on bag with a capacity limit of not more than 32,000 mAh.
The power bank batteries with a capacity of 20,000 mAh (or less than 100 watt-hours (Wh) can be carried onboard up to 20 batteries.
The power bank batteries with a capacity of 20,000–32,000 mAh (or between 100-160 watt-hours (Wh) can be carried onboard up to 2 batteries.
The power bank batteries with a capacity of 32,000 mAh (or more than 160 watt-hours (Wh) are not allowed on board.

The 32,000 mAh number is specified based on the electrical power of a power bank with a 160 Wh at approximately 5 Volts (32,000 mAh x 5 V = 160 Wh), of which 160 Wh is equivalent to 1/7 of the energy of 1 kg TNT bomb. [5]

Battery management

Q: Are different types of batteries handled differently? How?

A:

Used batteries are hazardous waste that cannot be disposed of by landfill or incineration like conventional waste. This is cause batteries contain metal elements, which cannot be decomposed naturally by landfills and creates air pollution when incinerated. Batteries also contain acidic electrolytes or toxic organic substances, thus they may leak and create environmental pollution in a landfill. Therefore, specific measures have been taken to ensure a proper handling of the battery. Battery management starts with collecting used and worn-out batteries, for example, small batteries, such as batteries in mobile phones and computers. It is consumer’s responsibility to dispose of them at the correct e-waste collection point. These batteries should not be disposed with general waste because they may be incinerated, thus creating environmental pollution. As for large batteries, such as lead-acid batteries used in automobiles or lithium-ion batteries used in electric vehicles, the entrepreneurs in the industrial sector, such as battery dealers or electric vehicle dealers, are responsible for collecting and handling used batteries under the supervision of the Department of Industrial Works. A battery collection process is followed by a separation process, which will sort out the types of batteries for further disposal or recycling. The principles of handling or recycling each type of battery are similar, i.e., discharging to reduce the energy of a battery and make sure that it will not spark, and then dismantling all parts to separate the electrolyte and materials in the battery before disposing or recycling process. In other words, the difference in handling each type of battery is the disposing or recycling procedure of battery materials since different batteries have different components.

Q: How should users dispose of the batteries to reduce their environmental impact? Is there a management system in Thailand? There are various Battery disposal points, and where do discarded batteries go?

A:

The user (or the consumer) should be aware of the proper disposal of the battery by separating the battery from the device in use first. Then put it in a sealed bag to avoid a short circuit and clearly label it as toxic waste, and discarded at various receiving points, such as department stores, mobile network shops, and post offices. However, if the battery cannot be removed, such as mobile phones batteries, large batteries (e.g., lead-acid batteries), or battery packs in electric vehicles, the consumers should return or replace the battery to the supplier and should not disassemble it to get valuable materials from the battery.

At present, lead-acid batteries are the most commonly used batteries in automobiles, therefore, the consumers or suppliers normally separate batteries to get the lead ingots. This will cause the smelters to receive lead poison through contact and respiratory tract, as well as creates environmental pollution. In addition, disposing of the acid that contains electrolytes inside the lead-acid batteries also directly impacts the environment.

In Thailand, no law specifically supports battery waste management, but there are laws related to electronic waste management, such as the Act (Act on Enhancement and Conservation of National Environment Quality B.E. 2535) that controls waste disposal and maintains environmental quality, the Factory Act B.E. 2535 that sets standards and methods for controlling waste from the factory, the Hazardous Substance Act B.E. 2535 that applies to those who manufacture, import, export or possess hazardous substances, and the Public Health Act (No. 2) B.E. 2550 that specify local administrative organizations must arrange for the proper separation, collection, and disposal of hazardous waste from the community. Currently, Thailand is in the process of pushing for a draft of the Act on the Management of Waste Electrical and Electronic Equipment B.E. (WEEE: Waste Electric and Electronic Equipment Act) [6]. This Act includes the Extended Producer Responsibility: EPR) and product recall systems, which allow an entrepreneur to retrieve more scrap batteries for recycling.

Q: Can batteries be recycled?

A:

Batteries can be recycled. There are various methods of recycling depending on the type and material inside the battery. At present, lead-acid batteries are in large quantities and mostly used in automobiles. The recycling of lead-acid batteries starts by pouring the acid out of the battery, then disassembling to separate the case and material for plastic cases to be recycled, and the internal material can be separated into lead oxides and plates, which are melted in the factory to smelt lead and recycle the elemental plates.

As for lithium-ion batteries, there will be more battery waste in the future due to the increased use of electric vehicles (xEV). It is estimated that by 2032, Thailand will have more than 22 million electric vehicles [7] , making the recycling of lithium-ion batteries a crucial topic in the future.

Since the material value of lithium-ion batteries accounts for 64% of the total battery value. [8] The deteriorated or failing lithium-ion batteries are checked for electrical performance and state-of-health of the battery first. If the battery is damaged in the electrical circuit or some cells in the module are damaged, it will be repaired or replaced, and then reused, which is called remanufacturing method. Moreover, if the battery has a State-of-health between 60-80%, it can be used in other applications that require less battery capacity, which is called battery repurposing or a second-life method, such as using batteries in deteriorated electric vehicles in stationary energy storage systems. Currently, Nissan Motor (Thailand) Company Limited has cooperated with Eaton Industries (Thailand) Ltd., to develop used lithium-ion batteries in Nissan leaf cars as a home backup power source, which is called xStorage. [9] However, if it was found that a state-of-health of batteries has a lower value than 60%, it can be recycled as shown in figure 3.

Battery recycling consists of four main processes:

The mechanical process: a process of decomposing and separating battery materials by a mechanical process, such as crushing, filtering, magnetization, and refrigeration.
The pyrometallurgical process: a process that uses heat to melt and smelt iron and bring back precious metals in the form of alloys.
The hydrometallurgical process: a process that uses chemicals by leaching and returning precious metals in the form of a salt solution.
The direct recycling process: a treatment for the material inside the battery that is directly deteriorated to make the deteriorated material to have a quality as original materials and can be used in the reassembled battery.

Recycling lithium-ion batteries involves a combination of the above processes [10] as shown in Figure 4, which each company from various countries has different ways to recycle lithium-ion batteries. [11] For example, the Umicore Company in Belgium, which has used the thermal metallurgy process in the smelting of precious metals such as cobalt, nickel, copper and iron into alloys and then melted by hydrometallurgical process to separate precious metals. As the Retriev Company in the United States, which has used liquid nitrogen to freeze batteries to prevent lithium reaction and then crush and separate the materials, it was then separated by hydrometallurgical process to to extract lithium and cobalt. In Thailand, there is no lithium-ion battery recycling plant, therefore, the entreprenuers will export used lithium-ion batteries to foreign countries for recycling.

References

BATTERY 2030+ Roadmap: Inventing the Sustainable Batteries of the Future, Research Needs and Future Actions, https://battery2030.eu/digitalAssets/861/c_861008-l_1-k_roadmap-27-march.pdf (accessed November 5, 2020).
เตือนภัยอย่าใช้มือถือขณะชาร์จแบต, การไฟฟ้าส่วนภูมิภาค, https://www.pea.co.th/ (accessed December 23, 2020)
T.D. Tran, J.H. Feikert, R.W. Pekala, K. Kinoshita, Rate effect on lithium-ion graphite electrode performance, J. Appl. Electrochem. 26 (1996) 1161–1167. https://doi.org/10.1007/BF00243741.
Traveling with Portable Electronic Devices (PEDs), https://www.iata.org/en/programs/ops-infra/baggage/ped/ (accessed November 27, 2020)
Energy and Work Conversion Table, https://www.unitconversion.org/unit_converter/energy-ex.html (accessed December 29, 2020)
บันทึกหลักการและเหตุผล ประกอบร่างพระราขบัญญัติการจัดการซากผลิตภัณฑ์เครื่องใช้ไฟฟ้าและอุปกรณ์อิเล็กทรอนิกส์ พ.ศ. …., https://www.lawamendment.go.th/index.php/faq?id=717 (accessed November 11, 2020)
รายงานแผนพัฒนาโครงสร้างพื้นฐานด้านไฟฟ้าเพื่อรองรับยานยนต์ไฟฟ้าของประเทศไทย, https://www.eppo.go.th/images/Infromation_service/studyreport/EV_plan.pdf (accessed November 11, 2020)
Pillot, Christophe. “Avicenne Energy.”Battery Market Compilations, twenty first ed. (2017).
Nissan and Eaton release ‘Xstorage’ – home energy storage solution, https://www.pntpower.com/nissan-eaton-release-xstorage-home-energy-storage-solution/ (accessed November 11, 2020)
M. Chen, X. Ma, B. Chen, R. Arsenault, P. Karlson, N. Simon, Y. Wang, Recycling End-of-Life Electric Vehicle Lithium-Ion Batteries, Joule. 3 (2019) 2622–2646. https://doi.org/10.1016/j.joule.2019.09.014.
Pinegar, Haruka, and York R. Smith. “Recycling of end-of-life lithium ion batteries, Part I: Commercial processes.”Journal of Sustainable Metallurgy (2019): 1-15.

Solar cell power

Wed, 23 Jun 2021 05:44:58 +0000

By Dr. Amornrat Limmanee, Solar Photovoltaic Team Leader of Solar Photovoltaic Research Team,Energy Innovation Research Group of ENTEC Interviewed by Dr. Buncha Thanaboonsombut Article by Mrs. Orawan Sumriddetkajorn

Q: Could you tell us about your educational background? We have known that you studied high school in Japan, right?

A:

After I graduated from junior high school in Thailand, I won a government scholarship to study in Japan for one year. Later, I continued to study high school until I graduated with a Ph.D. in physical electronics, totaling 13 years in Japan.

I have always had a passion for science and mathematics, therefore studying in Japan was a great opportunity since Japan is one the most advanced countries in the world in electronics technology. I, thus, chose to study electrical engineering.

Q: Why did you choose to study in depth about solar cells during your master’s-doctoral degree?

A:

I had previously studied semiconductors and electronic circuits during the bachelor’s degree, and my advisor informed me that in studying semiconductors, one must choose to focus on either diode or solar cell. Therefore, I chose to study solar cells because I have never had experience in solar cells but already studied diode and semiconductors. At that time, there were not many people working on solar cell research in Thailand, except Prof. Dr. Dusit Krea-ngam, Prof. Dr. Somsak Panyakaew and Dr. Phopon Sitchnukit.

Q: During a Ph.D study, what was your research topic? And which private company did you take an internship?

A:

My research topic was the development of a film layer in a crystalline silicon cell, which was an anti-reflection layer and reduces energy loss on the bottom and top electrodes by forming silicon nitride. Since solar cells require a lot of refraction, the top layer must be developed to reduce reflection and reduce other losses, therefore, I had developed silicon nitride film and silicon-oxide to be used in crystalline silicon cell structures.

During the internship, I worked at Mitsubishi Electric Corporation, where I learned about doing research and development of small cells, measurement and analysis of small cells and the actual fabricatiom process to create commercial solar panels.

Furthermore, subsidiary companies of Mitsubishi Electric not only produce various electrical and electronic devices but also have their own solar cell plantsl; however, most of them are sold within Japan and exported to countries other than Thailand. At that time, the company measured the properties of silicon wafers to determine which wafers would be suitable for building solar cells, as well as the selection and analysis method of how to achieve high efficiency and reduced loss.

Q: Since Japan has a strong reputation for the production of electronic devices and solar cells. If we consider global picture, is there any particular country to compete with Japan?

A:

10 years ago, Japan competed with Germany and the United States, and used to have the highest solar panel capacity in the world. But now, China is one of the key players in this market.

Q: When talking about solar cells, people usually think of black panels installed on the roof or on the ground. Could you give us an overview of solar photovoltaic technology and what does a solar cell consist of?

A:

A solar cell l is a semiconductor with energy band gaps that directly absorb the solar spectrum. There are various types of solar cells, but the most common is fabricated from silicon for its affordable prices and large quantities. However, some types are rare, e.g., those made for rare earth, which is expensive and has high production cost. The doped material creates a potential difference in the PN junction, the photon [1] creates the negatively charged electron and the positively charged hole, both of them could conduct electricity. A potential difference, therefore, causes the electrons to move in the opposite direction of the hole, and when a circuit is complete, electricity is generated.

[1] A photon is a particle of light and its energy depends on the wavelength of the light.

Q: How does the solar cell work? Does the research team view light as a wave or a particle?

A:

It can be viewed both ways. If we talk about an electron and a hole, then we consider light as particles because, in solar cell measurements, one need to measure quantum efficiency [2] to see how much light is converted into electricity at each wavelength. On the contrary, if we consider light as wave, the amount of light energy per square meter before conversion will be of interest in order to see the whole picture.

[2] quantum efficiency is the amount of electrons that the materials emitted per amount of photon absorbed.

Q: What are the main components of a solar cell system?

A:

A solar panel

It is a combination of cells connected to give the voltage and current required for the system.

An Inverter

This device is used with home appliances to convert direct current to alternating current because solar cells yield a direct current.

A battery

This device is required to store electrical energy produced from solar cells.

A charge controller

This device is necessary because the electricity produced from the solar cell may be irregular depending on the amount of sunlight; thus, it could damage the battery if charged directly.

Q: If we talk about solar cells, it is a material that receives light and then converts into electricity. But if we look at the whole system, Is it called a solar photovoltaic system?

A:

Yes, it is. Actually, there is another form of solar power generation, which is called a solar thermal to produce hot water or steam and then to generate electricity. However, if converted from light to direct electricity, it is called a solar photovoltaic system or solar PV system.

Q: From the point of view of materials that refer to different types of crystals such as monocrystalline, polycrystalline or multicrystalline, and amorphous, how do these crystals affect the difference in photovoltaic performance?

A:

The most efficient photovoltaic crystals are single crystals because they are homogeneous. However, if it is polycrystalline, there will be grain boundaries, which cause a lost in energy. In the past, single crystal was quite expensive, therefore, polycrystallines are widely employed, even though with lower efficiency. But in economic terms, they are cost-effective.

At present, China’s large-scale production of single crystals has caused the price of single crystals to plummet, thus making single crystals dominates the market. About 96% of silicon wafers used in the solar cell industry are made in China, allowing China to control both from upstream to downstream and causing a price reduction since 2010. The price per watt of solar cells was once as high as 80 baht per watt, but now it’s now reduced to only 20 baht per watt. At the solar farm level the cost is lower than 10 baht per watt. Thus the cost of solar energy is lower due to decrease panel prices. In other words, other countries cannot lower prices as much as China because China is a wafer producer, and once it is sold, China is able to fully control both price and quality.

Q: How competive is amorphous silicon thin film technology?

A:

About 10 years ago, amorphous silicon thin film is a film coating technique by using gases such as silane or hydrogen to create an amorphous silicon film on the glass substrate because the cost is cheaper than single crystal. Now, as the single crystal price was dropped to the same level as that of amorphous silicon thin film, thus causing the amorphous silicon thin film slowly disappeared from the market and only left in a very small proportion.

Q: If the demand for amorphous silicon decreases, will its research and development continue or decrease following the trend of the market?

A:

If the demand of for the amorphous silicon decreases, its research and development will be decreased and the amorphous silicon will be used as a layer in a crystalline silicon cell. It was originally used to fabricate solar cells but is now changed its role to be a supplement to increase the efficiency of crystalline silicon cells.

Q: While you were working at NECTEC, what was your research?

A:

At NECTEC, I was doing research on amorphous silicon thin films fabricated on a polyimide base, which was a flexible, rollable, portable plastic. At that time, in terms of technology, it was possible to make it in a laboratory measuring 10×10 cm 2, but to scale it up, it required a roll-to-roll processing machine, which had cost constraints. That is to say, when the production is low but the price is high, thus it is not economically viable. In addition, it is also difficult to find investors during the time that the crystals price were low, so others turned their attention to the crystal

Q: When the crystal price decreases, how do the research direction respond?

…

Solar cell powerRead More »

Pathompong Janetaisong

Tue, 02 Mar 2021 09:34:17 +0000

Pathompong Janetaisong

Research Assistant

Education

2014 M.Eng. in Materials Engineering Kasetsart University, Thailand
2010 B.Eng. in Materials Engineering Kasetsart University, Thailand

Expertise

Bio-Lubricant
Biodiesel
Biogas

Email:

pathompong.jan@entec.or.th