The rechargeable cells what power everything from phones to Priuses

July 10 [Wed], 2013, 16:55
The number one technological hurdle separating humanity from the Jetson Future we deserve is developing a reliable power supply. Even today, we're barely even able to keep out phones alive through the evening commute. But 497695-001 12 cells a radical departure in Lithium ion battery technology could help keep our power-hungry gadgets online for days, not hours.

Conventional Lithium ion batteries, the rechargeable cells what power everything from phones to Priuses, generate current by shuttling positive lithium ions between microscopically thin sheets of carbon graphite located at each electrode. But as these sheets age, their capacity and discharge performance degrades. This is especially true in the new generation of lithium-silicon cells (silicon replacing toxic cobalt as the battery's anode)—the mechanical stress of accepting and discharging electrons causes these silicon sheets to crack over time.

Researchers at the University of Southern California have therefore done away with silicon sheets entirely. According to a study published in the journal Nano Research reports, a team headed by Viterbi School of Engineering Pavilion g4 12 cells professor Chongwu Zhou instead uses fields of porous silicon nano-tubes to shuffle electrons without wearing down and without losing capacity. What's more, the team's provisional patent indicates that this new battery structure could hit the market in just two to three years.

Conventional Lithium ion batteries

May 23 [Thu], 2013, 10:57
The number one technological hurdle separating humanity from the Jetson Future we deserve is developing a reliable power supply. Even today, we're barely even able to keep out phones alive through the evening Pavilion g7 compatiblecommute. But a radical departure in Lithium ion battery technology could help keep our power-hungry gadgets online for days, not hours.

Conventional Lithium ion batteries, the rechargeable cells what power everything from phones to Priuses, generate current by shuttling positive lithium ions between microscopically thin sheets of carbon graphite located at each electrode. But as these sheets age, their capacity and discharge performance degrades. This is especially true in the new generation of lithium-silicon cells (silicon replacing toxic cobalt as the battery's anode)—the mechanical stress of accepting and discharging electrons causes these silicon sheets to crack over time.

Researchers at the University of Southern California have therefore done away with silicon sheets entirely. According to a study published in the journal Nano Research reports, a team headed by Viterbi School of Engineering 516916-001 compatibleprofessor Chongwu Zhou instead uses fields of porous silicon nano-tubes to shuffle electrons without wearing down and without losing capacity. What's more, the team's provisional patent indicates that this new battery structure could hit the market in just two to three years.

To obtain a reasonably good capacity reading

March 28 [Thu], 2013, 16:11
In the late 1700s, Charles-Augustin de Coulomb ruled that a battery that receives a charge current of one ampere (1A) passes one coulomb (1C) of charge every second. In 10 seconds, 10 coulombs pass into the12 cells 40Y8318, and so on. On discharge, the process reverses. Today, the battery industry uses C-rate to scale the charge and discharge current of a battery.

Most portable batteries are rated at 1C, meaning that a 1,000mAh battery that is discharged at 1C rate should under ideal conditions provide a current of 1,000mA for one hour. The same battery discharging at 0.5C would provide 500mA for two hours, and at 2C, the 1,000mAh battery would deliver 2,000mA for 30 minutes. 1C is also known as a one-hour discharge; a 0.5C is a two-hour, and a 2C is a half-hour discharge.

The battery capacity, or the amount of energy a battery can hold, can be measured with a battery analyzer. The analyzer discharges the battery at a calibrated current while measuring the time it takes to reach the end-of-discharge voltage. An instrument displaying the results in percentage of the nominal rating would show 100 percent if a 1,000mAh test battery could provide 1,000mA for one hour. If the discharge lasts for 30 minutes before reaching the end-of-discharge cut-off voltage, then the battery has a capacity of 50 percent. A new battery is sometimes overrated and can produce more than 100 percent capacity; others are underrated and never reach 100 percent even after priming.

When discharging a battery with a battery analyzer capable of applying different C?rates, a higher C?rate will produce a lower capacity reading and vice versa. By discharging the 1,000mAh battery at the faster 2C, or 2,000mA, the battery should ideally deliver the full capacity in 30 minutes. The sum should be the same as with a slower discharge since the identical amount of energy is being dispensed, only over a shorter time. In reality, internal resistance turns some of the energy into heat and lowers the resulting capacity to about 95 percent or less. Discharging the same 12 cells 43R9257at 0.5C, or 500mA over two hours, will likely increase the capacity to above 100 percent.

To obtain a reasonably good capacity reading, manufacturers commonly rate lead acid at 0.05C, or a 20-hour discharge. Even at this slow discharge rate, the battery seldom attains a 100 percent capacity. Manufacturers provide capacity offsets to adjust for the discrepancies in capacity if discharged at a higher C?rate than specified. Figure 1 illustrates the discharge times of a lead acid battery at various loads as expressed in C-rate.

They choose nickel-based systems instead

March 28 [Thu], 2013, 16:08
Reputable battery manufacturers do not supply lithium-ion cells to uncertified battery assemblers. This precaution is reasonable when considering the danger of explosion and fire when charging and discharging a Li-ion12 cells L08O6C02 pack beyond safe limits without an approved protection circuit.

Authorizing a battery pack for the commercial market and for air transport can cost $10,000 to $20,000. Such a high price is troubling when considering that obsolescence in the battery industry is common. Manufacturers often discontinue a cell in favor of higher capacities. The switch to the improved cell will require a new certification even though the dimensions of the new cell are the same as the previous model.

Cell manufacturers must comply with their own vigorous cell testing and we ask, “Why are additional tests required when using an approved cell?” The cell approvals cannot be transferred to the pack because the regulatory authorities do not recognize the safety confirmation of the naked cell. The finished battery must be tested separately to assure correct assembly and is registered as a standalone product. Read about Safety Concerns with Li-ion.

As part of the test, the finished battery must undergo electrical and mechanical assessment to meet the Recommendations on the Transport of Dangerous Goods on lithium-ion batteries for air shipment, rules set by the United Nations (UN). The electrical test stresses the battery by applying high heat, followed by a forced charge, abnormal discharge and an electrical short. During the mechanical test, the battery is crush-tested and exposed to high impact, shock and vibration. The UN Transport test also requires altitude, thermal stability, vibration, shock, short circuit and overcharge checks. The UN Transport works in conjunction with the Federal Aviation Administration(FAA), the US Department of Transport (US DOT) and the International Air Transport Association (IATA).*

The authorized laboratory performing the tests needs 24 battery samples consisting of 12 new packs and 12 specimens that have been cycled for 50 times. IATA wants to assure that the batteries in question are airworthy and have field integrity. Cycling them for 50 times before the test satisfies this requirement.

The high certification costs make many small manufacturers shy away from using Li-ion for low-volume products; they choose nickel-based systems instead. While strict control is justified, an uncertified Li-ion kept in the hands of the expert and out of aircraft would be acceptable, but controlling such movement in the12 cells 43R1967 public domain is next to impossible. This makes it hard for the hobbyist who wants to win a race with a high-powered Li-ion battery but is bogged down by many rules.

With recurring accidents while transporting lithium-based batteries by air, regulatory authorities will likely tighten the shipping requirements further. However, anything made too cumbersome and difficult will entice some manufacturers to trick the system, defeating the very purpose of protecting the traveling public. Read about How to Transport Batteries.

A discharge/charge may be beneficial for calibrating

November 30 [Fri], 2012, 14:57
Rechargeable batteries may not deliver their full rated capacity when new and will require formatting. While this applies to most battery systems, manufacturers of lithium-ion batteries disagree. They say that Li-ion is ready at birth replacement Latitude D830 batteryand does not need priming. Although this may be true, users have reported some capacity gains by cycling these batteries after long storage.

What’s the difference between formatting and priming? Both address capacities that are not optimized and can be corrected with cycling. Formatting completes the manufacturing process and occurs naturally during early usage when the battery is being cycled. Priming, on the other hand, is a conditioning cycle that is applied as a service tool to improve battery performance during usage or after prolonged storage. Priming relates mainly to nickel-based batteries.

Formatting of lead acid batteries occurs by applying a charge, followed by a discharge and recharge as part of regular use. Do not strain a new battery by giving it extra-heavy duty right away. Gradually work it in with moderate discharges like an athlete trains for weight lifting or long-distance running. Lead acid typically reaches the full capacity potential after 50 to 100 cycles. Do not over-cycle on purpose; this would wear the battery down too quickly.

Manufacturers advise to trickle charge a nickel-based battery for 16 to 24 hours when new and after a long storage. This allows the cells to adjust to each other and bring them to an equal charge level. A slow charge also helps to redistribute the electrolyte to eliminate dry spots on the separator that might have developed by gravitation.

Nickel-based batteries are not always fully formatted when they leave the factory. Applying several charge/discharge cycles through normal use or with a battery analyzer completes the formatting process. The number of cycles required to attain full capacity differs between cell manufacturers. Quality cells perform to specification after 5 to 7 cycles, while others may need 50 or more cycles to reach acceptable capacity levels. Lack of formatting might cause a problem when the industrial user expects a new battery to work to specification right out of the box. Organizations using batteries for critical applications often verify performance through a discharge/charge cycle as part of quality control. Automated analyzers (Cadex) apply as many cycles as needed to achieve full capacity.

Cycling also restores lost capacity when a nickel-based battery has been stored for six months or longer. Storage time, state-of-charge and the temperature under which the battery was stored govern the recovery. The longer the storage and warmer the temperature, the more cycles will be required to regain full capacity. Battery analyzers help in the priming functions.

Some scientists believe that with use and storage, a passivation layer builds up on the cathode of a lithium-ion cell. Also known as interfacial protective film (IPF), this layer restricts ion flow and increases the internal resistance. In the worst cases, the phenomenon can lead to lithium plating. Charging, and more effectively cycling, is known to dissolve the layer. Scientists do not fully understand the nature of this layer, and the few published resources on this subject only speculate that performance restoration with cycling is connected to the removal of the passivation layer. Some scientists deny outright the existence of the IPF, saying that the idea is highly speculative and inconsistent with existing studies. Another layer is the solid electrolyte interphase (SEI), which is said to form at the anode on the initial charge. SEI is an electric insulation yet provides sufficient ionic conductivity for proper function.

Whatever the truth may be, there is no parallel to “memory” of NiCd batteries, which require periodic cycling. The symptoms may appear similar but the mechanics are different. Nor can the effect be compared to sulfation of lead acid batteries.

Lithium-ion is a very clean system and does not need formatting when new, nor does it require the level of maintenance that nickel-based batteries do. The first charge is no different than the fifth or the 50th. Formatting makes little difference because the maximum capacity is available right from the beginning. Nor dell envy Latitude E6400 batterydoes a full discharge improve the capacity once faded. In most cases, a low capacity signals the end of life.

A discharge/charge may be beneficial for calibrating a “smart” battery, but this service only addresses the digital part of the pack and does nothing to improve the electrochemical battery. Instructions to charge a new battery for eight hours are seen as “old school” from the nickel battery days.

Let's walk through a cost analysis by considering the following scenario

November 30 [Fri], 2012, 14:54
Rechargeable batteries almost always make economic sense. The upfront cost of setting yourself up with rechargeable batteries and the charger may seem off-putting at first, especially when you realize that you'll want to have some extra batteries that can be recharging while you're running devices like your 12 cells Latitude D820 batteryWalkman, wireless computer mouse, and battery-powered toys.

Let's walk through a cost analysis by considering the following scenario. Say you have a few different devices that use AA batteries, and you want to be able to have a total of eight batteries to power them at any given time. You also want four spares that can be charging while the other batteries are in use.

The total cost for this scenario—12 rechargeable batteries plus the charger—will be about $75.00. That may sound like a lot of up-front spending when you consider that you can buy an 8-pack of disposable AA batteries for about five bucks. But if you're like most households and it seems like every other trip to the store finds you buying another 8-pack of throw-aways, then rechargeables will definitely be the better deal.

For instance, under the scenario above, if you're now buying a five-dollar 8-pack of batteries every month, that's a yearly cost of $60. After a little more than a year, your $75 initial investment in the rechargeable setup will be paid for, and the next 10 years of battery use will be free. Over that period, you would save $600! And it will be 1,000 fewer disposable batteries going into your nearby landfill or incinerator.

If you don't use that many batteries—say a couple of 8-packs per year—you could still actually save money over the long run with rechargeables, though that would depend on the types of uses. But rechargeable batteries make the most sense for devices that get heavy to moderate use and have a high to medium current draw. These are the devices you find yourself changing batteries for at least once a month, or every couple of months at a minimum.

There are some uses where rechargeable batteries simply do not make economic sense:
low-draw devices like rn873 KM74 laptop battery devices that have long idle times (measured in months), like emergency flashlights—unless you're willing to shell out the extra dough it takes to buy lithium-ion rechargeable batteries. (More on those below.)

Li-manganese with a lower internal resistance will result in a higher average voltage

November 02 [Fri], 2012, 11:09
The nominal voltage of lithium-ion had been 3.60V/cell. This is a practical figure because it represents three nickel-based batteries connected in series (3 x 1.2V = 3.6V). Some cell manufacturers mark their Li-ion products as 3.70V/cell or higher. This poses a marketing advantage because of higher watt-hours rn873 42T5263 on paper (multiplying voltage times current equals W). It also creates unfamiliar references of 11.1V and 14.8V when connecting three and four cells in series.

Let this higher voltage not cause confusion; equipment manufacturers will always adhere to the nominal cell voltage of 3.60V for most Li-ion systems, and the standard designation of 10.8V and 14.4V will always work.

How did this higher voltage creep in? To calculate the nominal voltage, we take a fully charged battery that measures 4.20V and then fully discharge it to 3.00V at a rate of 0.5C while plotting the average voltage. For Li-cobalt, the average voltage comes to 3.6V/cell. Performing the same discharge on a fully charged Li-manganese with a lower internal resistance will result in a higher average voltage.

Pure spinel has one of the lowest internal resistances, and the plotted voltage on a load moves up to between 3.70 and 3.80V/cell. This higher midpoint voltage does not change the full-charge and end-of-discharge51J0497 voltage threshold.

The phosphate-based lithium-ion deviates from others in the Li-ion family and the nominal cell voltages are specified at between 3.20 and 3.30V. Because of the voltage difference, the two lithium-ion families are not interchangeable. New lithium-based batteries will have other voltages and specialty chargers may be needed.

Most battery chemistries allow serial and parallel configuration

November 02 [Fri], 2012, 11:08
Battery packs achieve the desired operating voltage by connecting several cells in series, with each cell adding to the total terminal voltage. Parallel connection attains higher capacity for increased current handling, as each battery for A32-X64 cell adds to the total current handling. Some packs may have a combination of serial and parallel connections.

Laptop batteries commonly have four 3.6V Li-ion cells in series to achieve 14.4V and two strings of these 4 cells in parallel (for a pack total of 8 cells) to boost the capacity from 2,400mAh to 4,800mAh. Such a configuration is called 4S2P, meaning 4 cells are in series and 2 strings of these in parallel. Insulating foil between the cells prevents the conductive metallic skin from causing an electrical short. The foil also shields against heat transfer should one cell get hot.

Most battery chemistries allow serial and parallel configuration. It is important to use the same battery type with equal capacity throughout and never mix different makes and sizes. A weaker cell causes an 11.1v 5200mah 9cells A32-N82 battery imbalance. This is especially critical in a serial configuration and a battery is only as strong as the weakest link.

Imagine a chain with strong and weak links. This chain can pull a small weight but when the tension rises, the weakest link will break. The same happens when connecting cells with different capacities in a battery. The weak cells may not quit immediately but get exhausted more quickly than the strong ones when in continued use. On charge, the low cells fill up before the strong ones and get hot; on discharge the weak are empty before the strong ones and they are getting stressed.

This kind of swelling quickly breaks the electrical contacts in the anode

September 22 [Sat], 2012, 10:20
The anode is a critical component for storing energy in lithium-ion batteries. A team of scientists at the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) has designed a new kind of anode that can absorb eight times the lithium of current designs, and has maintained its greatly increased energy capacity after over a year of testing and many hundreds of charge-discharge cycles.

The secret is a tailored polymer that conducts electricity and binds closely to lithium-storing silicon particles, even as they expand to more than three times their volume during charging and then shrink again during discharge. The new anodes are made from low-cost materials, compatible with standard lithium-rn873 HSTNN-DB75 manufacturing technologies. The research team reports its findings in Advanced Materials, now available online.

High-capacity expansion
"High-capacity lithium-ion anode materials have always confronted the challenge of volume change -- swelling -- when electrodes absorb lithium," says Gao Liu of Berkeley Lab's Environmental Energy Technologies Division (EETD), a member of the BATT program (Batteries for Advanced Transportation Technologies) managed by the Lab and supported by DOE's Office of Vehicle Technologies.

Says Liu, "Most of today's lithium-ion batteries have anodes made of graphite, which is electrically conducting and expands only modestly when housing the ions between its graphene layers. Silicon can store 10 times more -- it has by far the highest capacity among lithium-ion storage materials -- but it swells to more than three times its volume when fully charged."

This kind of swelling quickly breaks the electrical contacts in the anode, so researchers have concentrated on finding other ways to use silicon while maintaining anode conductivity. Many approaches have been proposed; some are prohibitively costly.
One less-expensive approach has been to mix silicon particles in a flexible polymer binder, with carbon black added to the mix to conduct electricity. Unfortunately, the repeated swelling and shrinking of the silicon particles as they acquire and release lithium ions eventually push away the added carbon particles. What's needed is a flexible binder that can conduct electricity by itself, without the added carbon.

"Conducting polymers aren't a new idea," says Liu, "but previous efforts haven't worked well, because they haven't taken into account the severe reducing environment on the anode side of a lithium-ion battery, which renders most conducting polymers insulators."
One such experimental polymer, called PAN (polyaniline), has positive charges; it starts out as a conductor but quickly loses conductivity. An ideal conducting polymer should readily acquire electrons, rendering it conducting in the anode's reducing environment.

The signature of a promising polymer would be one with a low value of the state called the "lowest unoccupied molecular orbital," where electrons can easily reside and move freely. Ideally, electrons would be acquired from the lithium atoms during the initial charging process. Liu and his postdoctoral fellow Shidi Xun in EETD designed a series of such polyfluorene-based conducting polymers -- PFs for short.

When Liu discussed the excellent performance of the PFs with Wanli Yang of Berkeley Lab's Advanced Light Source (ALS), a scientific collaboration emerged to understand the new materials. Yang suggested conducting soft x-ray absorption spectroscopy on Liu and Xun's candidate polymers using ALS beamline 8.0.1 to determine their key electronic properties.

Says Yang, "Gao wanted to know where the ions and electrons are and where they move. Soft x-ray spectroscopy has the power to deliver exactly this kind of crucial information."
Compared with the electronic structure of PAN, the absorption spectra Yang obtained for the PFs stood out immediately. The differences were greatest in PFs incorporating a carbon-oxygen functional group (carbonyl).

"We had the experimental evidence," says Yang, "but to understand what we were seeing, and its relevance to the conductivity of the polymer, we needed a theoretical explanation, starting from first principles." He asked Lin-Wang Wang of Berkeley Lab's Materials Sciences Division (MSD) to join the research collaboration.

Wang and his postdoctoral fellow, Nenad Vukmirovic, conducted ab initio calculations of the promising polymers at the Lab's National Energy Research Scientific Computing Center (NERSC). Wang says, "The calculation tells you what's really going on -- including precisely how the lithium ions attach to the polymer, and why the added carbonyl functional group improves the process. It was quite impressive that the11.1v 5200mah 9cells HSTNN-IB72 calculations matched the experiments so beautifully."

The simulation did indeed reveal "what's really going on" with the type of PF that includes the carbonyl functional group, and showed why the system works so well. The lithium ions interact with the polymer first, and afterward bind to the silicon particles. When a lithium atom binds to the polymer through the carbonyl group, it gives its electron to the polymer -- a doping process that significantly improves the polymer's electrical conductivity, facilitating electron and ion transport to the silicon particles.

The process of converting plastic waste into bio-fuel is quite simple

September 22 [Sat], 2012, 10:17
Each day, we have lot of plastic waste disposal from our household. However, a latest technology has come into being that helps in converting this plastic waste disposal into a good source of green fuel. Not only does this technology helps save our environment from waste accumulation but also helps ushigh quality HSTNN-CB72 save lot of money... Let us find out how...

Renewable Energy Investment is Viable

As the cost of recovering non-renewable fuel supplies increases, the viability of investment in other alternatives improves. Some of the most recent developments offer additional benefits while overcoming the problems that are associated with the first generation bio-fuels. The use of sugar cane, maize and palm oil as the basic raw material for first generation fuels is controversial because the production of these feed stocks displaces food production.

In the case of palm oil, there is yet another added problem that rain forests are being destroyed in order to create more oil plantations. In contrast to this, the use of maize has been enthusiastically embraced as it has being of enormous economic benefit to communities especially in the corn-belt in North America.

Other Renewable Fuel Options

There are second generation bio-fuels that do not compete directly with food production because they are able to use the whole plant and not just the seed. They can even utilise the waste from food production. So, for example, a grain is used for food and the rest of the plant to manufacture bio-fuel. Similarly palm seeds can be used to produce oils for food and the husks for bio-fuel.

Plastic Waste Disposal Producing Green Fuel

Meanwhile, several companies have begun operating plants that convert waste plastic to bio-fuel by using a similar process. Among them, Cynar which is head quartered in London but had its first plant operating in Portlaoise in Ireland, aims to install up to 30 plants throughout the British Isles. Similar plants are already in operation in Thailand and India.

The process of converting plastic waste into bio-fuel is quite simple. It is similar to how alcohol is made. If you heat plastic waste in replacement HSTNN-DB72non oxygen environment, it will melt, but will not burn. After it has melted, it will start boiling and eventually evaporate. You just need to put those vapours through a cooling pipe and when cooled the vapours will condense to a liquid and some of the vapours with shorter hydrocarbon lengths will remain as a gas.

The exit of the cooling pipe is then going through a bubbler containing water to capture the last liquid forms of fuel and leave only gas that is then burned. If the cooling of the cooling tube is sufficient, then there will be no fuel in the bubbler, but if not, the water will capture all the remaining fuel that will float above the water and can be poured off the water. On the bottom of the cooling tube is a steel reservoir that collects all the liquid and it has a release valve on the bottom so that the liquid fuel can be poured out.

This method is doubly environmentally friendly as it will reduce the volume of plastic waste being disposed of in the landfill while producing green fuel without generating any green house gases.