고유가시대를 맞이 하면서 국내에서도 수소연료나 전기 등 차세대 에너지 자동차에 대한 관심이 높아지고 있습니다.
김해의 한 중소기업에서 전기자동차 구동의 핵심기술을 개발해 전기자동차 상용화를 추진하고 있습니다.
CJ 케이블넷 심지훈 기자가 보도합니다.
[리포트]
김해시 한림면의 국도 위를 작은 소형차 한대가 힘차게 달려갑니다.
겉보기에는 국내 기업의 경차와 다름없는 모습이지만 이 차는 휘발유 대신 100% 전기로 움직이는 차세대 전기 자동차입니다.
리튬베터리를 사용할 경우 한번 충전으로 최대 100km를 운행할 수 있고 최대 시속 60km로 달릴 수 있습니다.
김해의 한 중소기업에서 제작한 전기자동차의 핵심 기술은 모터제어기술.
저속으로 회전할 때 높은 출력과 정밀제어가 어려웠던 기존의 교류 모터의 문제를 해결하면서 전기자동차의 상용화에 한발 다가섰습니다.
그 동안 골프카나 전동지게차 등의 전기자동차에 사용됐던 직류 전원 모터는 기술적인 문제로 유지보수비용이 많이 드는 등 일반 자동차로 사용하기에는 어려운 점이 많았습니다.
[인터뷰:윤여진, 개발업자]
"저속회전에서 높은 힘을 낼 수 있는 기술개발이 상당히 어려웠기 때문에 못쓰고 있었는데 그런 부분을 저희들이 기술개발을 해서..."
전기자동차의 가장 큰 장점은 무엇보다 친환경 시스템.
전기로 자동차가 구동되면서 차량에서 온실가스는 전혀 발생되지 않으며 연료비로 따져도 10km에 200원 정도로 일반 휘발류 차량의 7분1 수준입니다.
[인터뷰:윤상기, 김해시 경제환경국장]
"우리시에서도 친환경정책을 펴고 있기 때문에 시에서 가급적이면 시험구매해서 시험적으로 운영할 계획입니다."
그동안 대기업을 중심으로 이뤄지던 차세대 자동차의 연구 개발이 지방 중소기업에서도 이뤄지면서 본격적인 친환경자동차의 상용화시대를 앞당기는 계기가 될것으로 전망되고 있습니다.
CJ 케이블넷 뉴스 심지훈입니다.
2009년 10월 30일 금요일
2009년 10월 25일 일요일
The Lithium Air Battery Race
October 14, 2009 | Leave a Comment
IBM has made a major splash in the battery industry with their announcement that the company is going to research lithium air battery technology. They are a little further along than the press and media are allowing. IBM plans to get a jump on the process by using its nano membrane technology developed for water-purification systems to separate water and other elements from the oxygen in air. They will use their nano-structure expertise developed for the semiconductor industry to help distribute oxygen evenly around the interior of the battery cells – preventing blockages. Supercomputing will be used to model techniques for moving individual atoms through the membranes.
The race is on because lithium air batteries approach the energy density of fuel cells without the plumbing and carrying the fuel needed for these devices; in theory, the maximum energy density is more than 5,000 watt-hours per kilogram, or more than 10 times that of today’s lithium-ion batteries. Lithium air batteries are also very lightweight because it’s not necessary to carry a second reactant.
Lithium Air Battery Activity Flow Chart. Click image for the largest view.
The main problem with using lithium metal as a battery electrode is the material reacts rapidly and violently with water. Lithium air batteries have been considered for decades, but there’s always water in the air. Exposure to even traces of water rapidly degrades the material. Lithium air batteries are unique in that instead of being a sealed system, they use atmospheric oxygen, essentially harnessing the oxygen in the air as the cathode of the battery. Since oxygen enters the battery on demand, it offers an essentially unlimited amount of reactant, metered only by the surface area of its electrodes.
That violent reaction with water has consequences. About 20 years ago the Canadian company Moli Energy recalled its rechargeable lithium-metal batteries, which used not air but a more traditional cathode, after one caught fire; the incident led to legal action, and the company declared bankruptcy. That was a very cold water splash.
Until the IBM announcement only a handful of labs around the world, including those at PolyPlus Battery in Berkeley, CA, Japan’s AIST and St. Andrews University, in Scotland, have been working on lithium air batteries. Since the IBM announcement news leaked that Toyota recently began looking into lithium air technology. Its not any kind of secret that General Electric is investing $150 million over five years to develop massive sodium batteries for use in locomotives and electrical grids. It has also made an equity investment in A123, a small company that supplies lithium-ion batteries for plug-in electric vehicles.
But IBM will partner with Oak Ridge, Lawrence Berkeley, Lawrence Livermore, Argonne, and Pacific Northwest national labs. The company and its collaborators are currently working on a proposal for funding from the U.S. Department of Energy under the Advanced Research Projects Agency-Energy bringing a very large and diverse set of intellects to the race.
Along with the water plus lithium violence potential there are two other problems. First, the design of the cathode needs to be optimized so that the lithium oxide that forms when oxygen is pulled inside the battery won’t block the oxygen intake channels. Second, better catalysts are needed to drive the reverse reaction that recharges the battery.
Recharging also has safety issues. When lithium air batteries are charged and discharged, there is an electroplating and then stripping of the metal over and over again in each cycle. Over time, just as in a lithium ion battery, the lithium air surface becomes rough, which can lead to thermal runaway, when the battery literally burns until all the reactants inside are used up. The savior in that is the lithium air construction would limit incoming air making such a heat buildup impossible without cracking open the battery case.
IBM is pursuing the risky technology attempt instead of lithium-ion batteries because it has the potential to reach high enough energy densities to change the transportation system. IBM Almaden Research Center’s manager of science and technology Chandrasekhar Narayan said, “With all foreseeable developments, lithium-ion batteries are only going to get about two times better than they are today. To really make an impact on transportation and on the grid, you need higher energy density than that.”
The motivator is a goal, a lightweight 500-mile battery for a family car. The Chevy Volt has only 40 miles on board and the Tesla can get to 300 miles before recharging. The room for growth is virtually the entire personal transport market, worldwide.
The U.S. also has another concern. IBM is also eager to reclaim U.S. leadership in battery tech from Asia. While many of the original breakthroughs for the batteries that power today’s laptop computers and cell phones happened in the U.S., those batteries now come primarily from Japan and Korea.
Industry leaders have called for just this kind of concerted effort amid concern that the U.S. will miss out on one of the most important technology shifts in history—the switch from gasoline to electricity as the primary power source for light vehicles. The worry is that the U.S. will trade its current dependency on the Middle East for oil with a new dependency on Asia for vehicle batteries. “We lost control of battery technology in the 1970s,” laments Andy Grove, former chairman of chip giant Intel. “Battery technology will define the future, and if we don’t act quickly it will go to China and Japan.”
The race is on. Major players in industry and science are on board. The problems to start with are well known. Experience in other fields might bring solutions. That electric drive for personal transport looks more likely each time the news is checked. Storage for intermittent grid generation is getting answered as well. Batteries are getting more interesting than seen in decades with idled ideas getting new life from connections with other technologies. It’s a major race, indeed.
IBM has made a major splash in the battery industry with their announcement that the company is going to research lithium air battery technology. They are a little further along than the press and media are allowing. IBM plans to get a jump on the process by using its nano membrane technology developed for water-purification systems to separate water and other elements from the oxygen in air. They will use their nano-structure expertise developed for the semiconductor industry to help distribute oxygen evenly around the interior of the battery cells – preventing blockages. Supercomputing will be used to model techniques for moving individual atoms through the membranes.
The race is on because lithium air batteries approach the energy density of fuel cells without the plumbing and carrying the fuel needed for these devices; in theory, the maximum energy density is more than 5,000 watt-hours per kilogram, or more than 10 times that of today’s lithium-ion batteries. Lithium air batteries are also very lightweight because it’s not necessary to carry a second reactant.
Lithium Air Battery Activity Flow Chart. Click image for the largest view.
The main problem with using lithium metal as a battery electrode is the material reacts rapidly and violently with water. Lithium air batteries have been considered for decades, but there’s always water in the air. Exposure to even traces of water rapidly degrades the material. Lithium air batteries are unique in that instead of being a sealed system, they use atmospheric oxygen, essentially harnessing the oxygen in the air as the cathode of the battery. Since oxygen enters the battery on demand, it offers an essentially unlimited amount of reactant, metered only by the surface area of its electrodes.
That violent reaction with water has consequences. About 20 years ago the Canadian company Moli Energy recalled its rechargeable lithium-metal batteries, which used not air but a more traditional cathode, after one caught fire; the incident led to legal action, and the company declared bankruptcy. That was a very cold water splash.
Until the IBM announcement only a handful of labs around the world, including those at PolyPlus Battery in Berkeley, CA, Japan’s AIST and St. Andrews University, in Scotland, have been working on lithium air batteries. Since the IBM announcement news leaked that Toyota recently began looking into lithium air technology. Its not any kind of secret that General Electric is investing $150 million over five years to develop massive sodium batteries for use in locomotives and electrical grids. It has also made an equity investment in A123, a small company that supplies lithium-ion batteries for plug-in electric vehicles.
But IBM will partner with Oak Ridge, Lawrence Berkeley, Lawrence Livermore, Argonne, and Pacific Northwest national labs. The company and its collaborators are currently working on a proposal for funding from the U.S. Department of Energy under the Advanced Research Projects Agency-Energy bringing a very large and diverse set of intellects to the race.
Along with the water plus lithium violence potential there are two other problems. First, the design of the cathode needs to be optimized so that the lithium oxide that forms when oxygen is pulled inside the battery won’t block the oxygen intake channels. Second, better catalysts are needed to drive the reverse reaction that recharges the battery.
Recharging also has safety issues. When lithium air batteries are charged and discharged, there is an electroplating and then stripping of the metal over and over again in each cycle. Over time, just as in a lithium ion battery, the lithium air surface becomes rough, which can lead to thermal runaway, when the battery literally burns until all the reactants inside are used up. The savior in that is the lithium air construction would limit incoming air making such a heat buildup impossible without cracking open the battery case.
IBM is pursuing the risky technology attempt instead of lithium-ion batteries because it has the potential to reach high enough energy densities to change the transportation system. IBM Almaden Research Center’s manager of science and technology Chandrasekhar Narayan said, “With all foreseeable developments, lithium-ion batteries are only going to get about two times better than they are today. To really make an impact on transportation and on the grid, you need higher energy density than that.”
The motivator is a goal, a lightweight 500-mile battery for a family car. The Chevy Volt has only 40 miles on board and the Tesla can get to 300 miles before recharging. The room for growth is virtually the entire personal transport market, worldwide.
The U.S. also has another concern. IBM is also eager to reclaim U.S. leadership in battery tech from Asia. While many of the original breakthroughs for the batteries that power today’s laptop computers and cell phones happened in the U.S., those batteries now come primarily from Japan and Korea.
Industry leaders have called for just this kind of concerted effort amid concern that the U.S. will miss out on one of the most important technology shifts in history—the switch from gasoline to electricity as the primary power source for light vehicles. The worry is that the U.S. will trade its current dependency on the Middle East for oil with a new dependency on Asia for vehicle batteries. “We lost control of battery technology in the 1970s,” laments Andy Grove, former chairman of chip giant Intel. “Battery technology will define the future, and if we don’t act quickly it will go to China and Japan.”
The race is on. Major players in industry and science are on board. The problems to start with are well known. Experience in other fields might bring solutions. That electric drive for personal transport looks more likely each time the news is checked. Storage for intermittent grid generation is getting answered as well. Batteries are getting more interesting than seen in decades with idled ideas getting new life from connections with other technologies. It’s a major race, indeed.
Development of an Easily Recyclable “Lithium-Copper Rechargeable Battery”
Development of an Easily Recyclable “Lithium-Copper Rechargeable Battery”
- An innovative high-capacity, low-cost storage battery using metals as positive and negative electrodes -
( Translation of AIST press release of August 24, 2009 )
Points
A solid electrolyte separator divides the organic electrolyte solution used on the negative electrode side and the aqueous electrolyte solution used on the positive electrode side.
The discharge capacity density of the positive electrode active material (843 mAh/g) exceeds that of conventional lithium-ion batteries by five times or more.
The battery includes electrodes made of metallic lithium and copper, because of which easy recycling of the electrode materials is possible.
Summary
Haoshen Zhou (Leader), the Energy Interface Technology Group, the Energy Technology Research Institute (Director: Yasuo Hasegawa) of the National Institute of Advanced Industrial Science and Technology (AIST) (President: Tamotsu Nomakuchi), and Yonggang Wang (Japan Society for the Promotion of Science (JSPS) Postdoctoral Fellow), have succeeded in developing an easily recyclable high-capacity “lithium-copper rechargeable battery.”
Lithium-ion batteries are widely used in cellular phones and notebook PCs. Recently, extensive research has been conducted on the development of high-capacity lithium-ion batteries for electric vehicles. Owing to limited lithium resources, the development of inexpensive and recyclable lithium-ion batteries is expected.
In our lithium-copper rechargeable battery, the negative electrode made of metallic lithium is dipped into an organic electrolyte solution, and the positive electrode made of metallic copper is dipped into an aqueous electrolyte solution. Mixing of the two electrolyte solutions is prevented by using a solid electrolyte separator. Lithium ions (Li+) can pass through the separator, while other ions (Cu2+, H+, OH-, etc.) cannot migrate from the aqueous electrolyte to the organic electrolyte; hence, the battery reactions proceed smoothly. The discharge capacity density of this battery is 843 mAh/g (per unit weight of copper consumed in the positive electrode reaction), which is more than five times the capacity of positive electrode in conventional lithium-ion batteries. The discharge capacity decreases only slightly even after 100 charge/discharge cycles. Recycling of conventional lithium-ion batteries, which contain electrodes having complex structures, is extremely difficult. However, the electrodes in our lithium-copper battery are made of metallic lithium and copper and have simple chemical reaction concept and electrode structures; hence, the manufacturing cost of this battery is low, and it can be easily recycled.
The results of this research will be presented at Scalable Energy Storage, which is sponsored by IBM, held in San Jose, USA, on August 26 and 27, 2009.
(left): Schematic illustration of the novel “lithium-copper rechargeable battery”
(right): Comparison of performances of the lithium-copper battery and a conventional lithium-ion battery
Unit: Discharge capacity per unit weight of active material used in the positive electrode (mAh/g)
Research Background
Lithium-ion batteries are widely used in cellular phones and notebook PCs, and extensive research is being carried out on the development of high-capacity batteries that can be used in electric vehicles. However, in the conventional lithium-ion batteries, the positive electrode contains cobalt or manganese, whose resources are limited. Further, when manufacturing these batteries, complex and expensive processes such as high-temperature sintering and control of fine structures are necessary. In addition, when recycling dead batteries (after hundreds or thousands of charge/discharge cycles), it is difficult to separate the active material from conductive additives, carbon, binder and the collector electrode. To overcome these problems, it is expected to develop inexpensive, high-capacity lithium-ion batteries that can be easily recycled.
History of Research
Research carried out on the development of next-generation lithium-ion batteries at the Energy Technology Research Institute, AIST, showed that nano-structuring of electrode materials helps increase the power density of these batteries (AIST press releases on January 18, 2005; November 19, 2007; and August 27, 2008). Extensive studies have also been carried out on the development of “lithium-air batteries” with enhanced energy density for use in electric vehicles (AIST press release on February 24, 2009). Currently, researchers at AIST are focusing on the development of high-capacity lithium-ion batteries that can be easily recycled.
This research was supported in part by the Grants-in-Aid for Scientific Research of JSPS.
Details of Research
In this study, we have developed a rechargeable battery in which organic and aqueous electrolyte solutions are used on the negative electrode (metallic lithium) and positive electrode (metallic copper) sides, respectively; the two electrolyte solutions are partitioned by a solid electrolyte separator to prevent them from mixing. The electrolyte separator allows only lithium ions (Li+) to pass to the positive electrode side, but does not allow any other ions (Cu2+, H+, OH-, etc.) to migrate to the organic electrolyte on the negative electrode side; hence, stable battery reactions (charging/discharging) are realized.
During charging, the following reactions occur at the electrodes:
1) Negative electrode: Li+ + e- → Li
Lithium ions (Li+) from the aqueous electrolyte solution on the positive electrode side pass through the solid electrolyte separator and reach the surface of the negative electrode; here, they are supplied with the electrons from the external circuit and precipitate as metallic lithium (plating).
2) Positive electrode: Cu → Cu2+ + 2e-
Metallic copper dissolves in the aqueous electrolyte solution as copper ions (Cu2+), and electrons are released to the external circuit.
The following reactions occur during discharging:
1) Negative electrode: Li → Li+ + e-
Metallic lithium dissolves as lithium ions (Li+) in the organic electrolyte solution, and electrons are released to the external circuit. The lithium ions then migrate to the aqueous electrolyte solution on the positive electrode side through the solid electrolyte separator.
2)Positive electrode: Cu2+ + 2e- → Cu
The copper ions (Cu2+) migrating from the aqueous electrolyte solution to the surface of the positive electrode precipitates as metallic copper with the electrons supplied from the external circuit.
Figure 1. Charge/discharge curves (left) and charge/discharge cycle performance properties (right) of the developed battery
The density of the discharge capacity of the positive electrode in this lithium-copper battery is around 843 mAh/g (per gram of copper reacting on the positive electrode). This discharge capacity is substantially larger than that of the positive electrode of a conventional lithium-ion battery (120–150 mAh/g, a literature value). From Fig. 1 (left), it is apparent that the discharge capacity of our battery decreases only slightly even after 100 charge/discharge cycles.
The electrodes in the lithium-copper rechargeable battery are constructed from pure metals and have simple structures. During charging and discharging, dissolution of the metal ions and precipitation (plating) of the metal occur. Therefore, the active electrode materials remain in metallic form after use, and this enables easy recycling of the materials (collection and recovery of active materials). Besides, since the aqueous and organic electrolyte solutions are divided by the solid electrolyte separator, each electrolyte can be recovered separately. Thus, recycling of these batteries is markedly easier than that of conventional lithium-ion batteries, because the recycling cost of the novel battery is expected to be very low.
The charging/discharging reactions occurring in this battery involve dissolution of metal ions on the metal surface and ”plating” of the metal electrode surface, and no complex processes such as compound formation occur; therefore, the current density of charge/discharge in this battery is expected to be very high. However, the lithium ion conductivity of the solid electrolyte separator is not sufficiently high, and hence, further research is necessary for enhancing the power density.
Future Study
Although the discharge capacity density of the lithium-copper rechargeable battery developed in this study is much larger than that of conventional lithium-ion batteries, its power density must be improved so that it can be used in electric vehicles that consume a large amount of power. This will be possible if the lithium ion conductivity of the solid electrolyte separator is increased. AIST is planning to carry out further research for increasing the power density of this lithium-copper rechargeable battery.
2009년 10월 24일 토요일
IBM Invests in Battery Research
IBM Invests in Battery Research
The company hopes to develop powerful, lightweight lithium-air batteries.
By Katherine Bourzac
Thursday, June 11, 2009
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IBM Research is beginning an ambitious project that it hopes will lead to the commercialization of batteries that store 10 times as much energy as today's within the next five years. The company will partner with U.S. national labs to develop a promising but controversial technology that uses energy-dense but highly flammable lithium metal to react with oxygen in the air. The payoff, says the company, will be a lightweight, powerful, and rechargeable battery for the electrical grid and the electrification of transportation.
Waterproof power: This protective casing envelops a functioning lithium-metal battery electrode, excluding water but letting lithium ions pass. It’s part of a prototype battery made by PolyPlus Battery of Berkeley, CA.
Credit: PolyPlus
Lithium metal-air batteries can store a tremendous amount of energy--in theory, more than 5,000 watt-hours per kilogram. That's more than ten-times as much as today's high-performance lithium-ion batteries, and more than another class of energy-storage devices: fuel cells. Instead of containing a second reactant inside the cell, these batteries react with oxygen in the air that's pulled in as needed, making them lightweight and compact.
IBM is pursuing the risky technology instead of lithium-ion batteries because it has the potential to reach high enough energy densities to change the transportation system, says Chandrasekhar Narayan, manager of science and technology at IBM's Almaden Research Center, in San Jose, CA. "With all foreseeable developments, lithium-ion batteries are only going to get about two times better than they are today," he says. "To really make an impact on transportation and on the grid, you need higher energy density than that." One of the project's goals, says Narayan, is a lightweight 500-mile battery for a family car. The Chevy Volt can go 40 miles before using the gas tank, and Tesla Motors' Model S line can travel up to 300 miles without a recharge.
One of the main challenges in making lithium metal-air batteries is that "air isn't just oxygen," says Jeff Dahn, a professor of materials science at Dalhousie University, in Nova Scotia. Where there's air there's moisture, and "humidity is the death of lithium," says Dahn. When lithium metal meets water, an explosive reaction ensues. These batteries will require protective membranes that exclude water but let in oxygen, and are stable over time.
Story continues below
IBM does not currently have battery research programs in place. However, Narayan says that IBM has the expertise needed to tackle the science problems. In addition to Oak Ridge, IBM will partner with Lawrence Berkeley, Lawrence Livermore, Argonne, and Pacific Northwest national labs. The company and its collaborators are currently working on a proposal for funding from the U.S. Department of Energy under the Advanced Research Projects Agency-Energy.
Research on lithium-metal batteries stalled about 20 years ago. In 1989, Canadian company Moli Energy recalled its rechargeable lithium-metal batteries, which used not air but a more traditional cathode, after one caught fire; the incident led to legal action, and the company declared bankruptcy. Soon after, Sony brought to market the first rechargeable lithium-ion batteries, which were safer, and research on lithium-metal electrodes slowed nearly to a halt. (After restructuring, Moli Energy refocused its research efforts and is now selling lithium-ion batteries under the name Molicel.) Only a handful of labs around the world, including those at PolyPlus Battery, in Berkeley, CA, Japan's AIST, and St. Andrews University, in Scotland, are currently working on lithium-air batteries.
Waterproof Lithium-Air Batteries
Waterproof Lithium-Air Batteries
A California company's lithium metal-air batteries are lightweight and energy dense.
By Katherine Bourzac
Friday, June 26, 2009
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A company based in Berkeley, CA, is developing lightweight, high-energy batteries that can use the surrounding air as a cathode. PolyPlus is partnering with a manufacturing firm to develop single-use lithium metal-air batteries for the government, and it expects these batteries to be on the market within a few years. The company also has rechargeable lithium metal-air batteries in the early stages of development that could eventually power electric vehicles that can go for longer in between charges.
Water power: A prototype battery made by PolyPlus uses lithium metal as the anode and salt water as the cathode to power an LED. As the battery discharges, lithium ions diffuse into the water, but the device doesn’t harm the surrounding clown fish.
Credit: PolyPlus
Interest in lithium metal-air batteries has been growing in recent years, along with the demand for lighter power sources for devices ranging from plug-in hybrid vehicles to laptops. In lithium-ion batteries, the electrodes are made of materials such as graphite, while in a lithium-metal battery, the anode is made up entirely of lithium metal, and the surrounding air can act as the cathode.
Lithium-metal batteries approach the energy density of fuel cells without the plumbing needed for these devices; in theory, the maximum energy density is more than 5,000 watt-hours per kilogram, or more than 10 times that of today's lithium-ion batteries. Lithium metal-air batteries are also very lightweight because it's not necessary to carry a second reactant. Lithium metal is "the holy-grail battery material," says Steven Visco, chief technical officer and founder of PolyPlus.
IBM recently announced that it would develop lithium metal-air batteries for the energy grid and for transportation. "Lithium ion is the gold standard, but what can beat it is lithium metal," says Paul Beach, president of battery manufacturer Quallion of Sylmar, CA.
Using lithium metal as a battery electrode, however, has proved problematic, mainly because the material reacts rapidly and violently with water. "People have thought about lithium-air batteries for decades, but there's always water in the air," says Visco. Exposure to even traces of water rapidly degrades the material.
Story continues below
PolyPlus has solved this problem by developing what the company calls a "protected lithium electrode." The device consists of a flat, rectangular piece of lithium metal overlaid on either side with a ceramic electrolyte material called lisicon. The solid electrolyte is impermeable to water but lets lithium ions pass through. Another coating protects the electrolyte from reacting with the lithium metal. And finally, the edges of the device are sealed with an aluminum-polymer laminate similar to a potato-chip bag. The laminate provides a watertight seal, and it's flexible, so it doesn't create any strain when the electrode shrinks with use.
When the lithium-metal electrode is placed in water, lithium ions leak out and react with oxygen dissolved in the water or with the water itself. To make a lithium metal-air battery, the device is fitted with a gas-diffusion electrode similar to those used for zinc metal-air hearing-aid batteries. When the battery is switched on, the electrode draws in oxygen through the membrane to react with the lithium ions. But unlike hearing-aid batteries, these devices won't self-discharge over time. "You can leave the battery on the shelf for months and expect it to work because the membrane protects it," says Visco. And because they're based on high-energy lithium metal, these batteries last much longer and are more lighter than zinc-air batteries.
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Aluminum Air Battery 만드는 법
Aluminum Air Battery
Foiled again
Introduction
A simple battery can be made from aluminum foil, salt water and activated charcoal that will make 1 volt and 100 milliamps.
Material
Modesto gathers the materials for an aluminum air battery.
Aluminum foil
Activated Charcoal, for aquariums
salt, water, a bowl
paper towel
two clip leads
a DC motor, masking tape
optional,l an electric meter capable of measuring 1 volt and 1 amp.
Assembly
Make a saturated salt solution by mixing salt and water in the bowl. Some undissolved salt should remain in the bottom of the bowl after mixing.
Shaking salt all around the vicinity of the bowl Modesto Tamez shows the chemical precision mixing needed to make the salt water solution...none.
Lay down a sheet of aluminum foil (approximately 30 cm long by 15 cm wide.)
Cover the aluminum foil with a doubled over piece of paper towel.
Soak the paper towel in the salt solution before using it to cover the aluminum.
Chef Modesto begins to prepare his burrito battery. He places salt water soaked paper towel over a sheet of aluminum foil.
Pour a layer of activated charcoal over the wet paper. Make it about a centimeter thick.
Make a layer of activated charcoal over the wet paper.
Place one metal lead on top of the carbon.
Clip the second lead to the aluminum foil.
Fold the aluminum foil over to make a burrito.
Important points:
The internal metal lead should touch only carbon,
The paper should keep the carbon from direct contact with the aluminum foil.
The aluminum foil is folded over to make a burrito with one electrical lead in its center.
Attach a "flag" made of masking tape to the shaft of the motor.
Clip the other electrical lead to the aluminum foil.
Clip both leads to the motor.
To Do and Notice
Notice that nothing happens.
Push down on the burrito and notice that the motor spins rapidly.
Pressing on the battery increases the current it delivers to the motor.
Measure the voltage and current produced by the battery, perhaps 1 volt and 100 ma. Notice that the outside aluminum electrode is the low voltage electrode, it is the source of electrons.
What's Going On?
This is called an aluminum air battery. The reaction that powers the battery occurs between the aluminum foil and oxygen from the air. The battery will deliver power for tens of minutes as the aluminum oxidizes.
Activated charcoal has many gas pockets giving it a large surface area this surface area provides the oxygen electrode.
The reaction with aluminum occurs in aqueous solution.
The maximum current delivered by the battery is determined by the voltage produced by the battery and by the internal resistance of the battery. The internal resistance can be reduced by making the electrode areas larger. It is also reduced by using salt water which has a lower resistance than pure water. The charcoal is a conductor, but its resistance decreases as the grains are pressed together.
So What?
The aluminum air battery produces useful amounts of power from safe chemicals.
Acknowledgments:
This activity was developed by Modesto Tamez from materials presented at the Exploratorium by Japanese teachers from Galileo Workshop.
Lithium-Air Battery
Lithium-Air Battery Could Have Up to 10x Storage Capacity of Current Lithium-Ion Tech
by Michael Graham Richard, Ottawa, Canada on 05.18.09
Science & Technology
Buzz up!
Photo: EPSRC
Will this Turn Out to Be the Battery Breakthrough We've Been Waiting For?
It's still too early to tell if this lithium-air battery technology will perform well enough to make its way to real-world products, but the lab results that have been publicized so far are very promising. With current battery chemistry, "energy storage is limited by the lithium cobalt oxide electrode (0.5 Li/Co, 130 mAhg-1). The University of St Andrews design replaces the lithium cobalt oxide electrode with a porous carbon electrode and allows Li+ and e- in the cell to react with oxygen from the air." This could allow up an increase in storage capacity by up to 10x. Read on for more details.
The EPSRC says:
The new design has the potential to improve the performance of portable electronic products and give a major boost to the renewable energy industry. The batteries will enable a constant electrical output from sources such as wind or solar, which stop generating when the weather changes or night falls.
Improved capacity is thanks to the addition of a component that uses oxygen drawn from the air during discharge, replacing one chemical constituent used in rechargeable batteries today. Not having to carry the chemicals around in the battery offers more energy for the same size battery. Reducing the size and weight of batteries with the necessary charge capacity has been a long-running battle for developers of electric cars.
I guess this means that this battery wouldn't work under water or in outter space. Not exactly a problem for most people...
Cheaper Too?
Another advantage is that this new porous carbon electrode would be cheaper than the current lithium cobalt oxide component it would replace.
But of course it's still in the lab, and professor Peter Bruce of the Chemistry Department at the University of St Andrews estimates that it will be at least five years before the STAIR cell is commercially available. Still, it's good to know that this is in the pipeline. What I wonder is if this can be combined with other types of battery chemistries and other breakthroughs...
Via Green Car Congress
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