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Industrial Applications

Industrial applications have unique power needs and the choice of battery is important. While consumer products demand high energy density to obtain slim and elegant designs, industry focuses on durability and reliability. Industrial batteries are commonly bulkier than those used in consumer products but achieve a longer service life.

Batteries are electro-chemical devices that convert higher-level active materials into an alternate state during discharge. The speed of such transaction determines the load characteristics of a battery. Also referred to as concentration polarization, the nickel and lithium-based batteries are superior to lead-based batteries in reaction speed. This attribute reflects in good load characteristics.

Discharge loads range from a low and steady current flow of a flashlight to intermittent high current bursts in a power tool, to sharp current pulses on digital communications equipment, laptops and cameras. In this paper we evaluate how the various battery chemistries perform in a given application.

What’s the best battery for video cameras?

Nickel-cadmium batteries continue to power a large percentage of professional cameras. This battery provided reliable service and performs well at low temperature. nickel-cadmium is one of the most enduring batteries in terms of service life but has only moderate energy density and needs a periodic full discharge.

The need for longer runtimes is causing a switch to nickel-metal-hydride. This battery offers up to 50% more energy than nickel-cadmium. However, the high current spikes drawn by digital cameras have a negative affect and the nickel-metal-hydride battery suffers from short service life.

There is a trend towards lithium-ion. Among rechargeables, this chemistry has the highest energy density and is lightweight. A steep price tag and the inability to provide high currents are negatives.

The 18650 cylindrical lithium-ion cell offers the most economical power source. “18” defines the cell’s diameter in millimeters and “650” the length. No other lithium-ion cell, including prismatic or polymer types, offers a similar low cost-per-watt ratio.

Over the years, several cell versions of 18650 cells with different Ah ratings have emerged, ranging from 1.8Ah to well above 2Ah. The cells with moderate capacities offer better temperature performance, enable higher currents and provide a longer service life than the souped up versions.

The typical 18650 for industrial use is rated at 2Ah at 3.60 volts. Four cells are connected in series to obtain the roughly 15 volts needed for the cameras. Paralleling the cells increases the current handling by about 2A per cell. Three cells in parallel would provide about 6A of continuous power. Four cells in series and three in parallel is a practical limit for the 18650 system.

Lithium-ion requires a protection circuit to provide safe operations under all circumstances. Each cell in series is protected against voltage peaks and dips. In addition, the protection circuit limits each cell to a current about 2A. Even if paralleled, the current of a lithium-ion pack is not high enough to drive digital cameras requiring 10 to 15A peak current. Tests conducted at Cadex Electronics have shown that the 18650 allows short current peaks above the 2A/cell limit. This would allow the use of lithium-ion on digital cameras, provided the current bursts are limited to only a few seconds.

What’s the best battery for still cameras?

The power requirement of a professional digital camera is sporadic in nature. Much battery power is needed to take snapshots, some with a powerful flash. To view the photo, the backlit color display draws additional power. Transmitting a high-resolution image over the air depletes another portion of the energy reserve.

Most non-professional cameras use a primary lithium battery. This battery type provides the highest energy density but cannot be recharged. This is a major drawback for professional use. Rechargeable batteries are the answer and lithium-ion fits the bill but faces similar challenges to the video cameras.

battery for still cameras

What is the best battery for medical devices?

One of the most energy-hungry portable medical devices is the heart defibrillator. The battery draws in excess of 10 amperes during preparation stages. Several shocks may be needed to get the patient’s heart going again. The battery must not hamper the best possible patient care.
battery for medical devices
Most defibrillators are powered by nickel-cadmium. nickel-metal-hydride is also being used but there is concern of short service life. In a recent study, however, it was observed that a defibrillator battery cycles far less than expected. Instead of the anticipated 200 cycles after two years of seemingly heavy use, less than 60 cycles had been delivered on the battery examined. ‘Smart’ battery technology makes such information possible. With fewer cycles needed, the switch to higher energy-dense batteries becomes a practical alternative.

Sealed lead-acid batteries are often used to power defibrillators intended for standby mode. Although bulky and heavy, the Lead-acid has a low self-discharge and can be kept in prolonged ready mode without the need to recharge. Lead-acid performs well on high current spurts. During the rest periods the battery disperses the depleted acid concentrations back into the electrode plate. Lead-acid would not be suitable for a sustained high load.

The medical industry is moving towards lithium-ion. The robust and economical 18650 cells make this possible. The short but high current spurts needed for defibrillators are still a challenge. Paralleling the cells and adding current-limiting circuits that allow short spikes of high current will help overcome this hurdle.

What is the best battery for power tools?

Power tools require up to 50 amperes of current and operate in an unfriendly environment. The tool must perform at sub zero temperatures and endure in high heat. The batteries must also withstand shock and vibration.

Most power tools are equipped with nickel-cadmium batteries. nickel-metal-hydride has been tried with limited success. Longevity is a problem but new designs have improved. lithium-ion is too delicate and could not provide the high amperage. Lead-acid is too bulky and lacks persistent power delivery. The power tool has simply no suitable alternatives to the rugged and hard-working nickel-cadmium.

In an attempt to pack more energy into power tools, the battery voltage is increased. Because of heavy current and application at low temperatures, cell matching is important. Cell matching becomes more critical as the number of cell connected in series increases. A weak cell holds less capacity and is discharged more quickly than the strong ones. This imbalance causes cell reversal on the weak cell if the battery is discharged at high current below 1V/cell. An electrical short occurs in the weak cell if exposed to reverse current and the pack needs to be replaced. The higher the battery voltage, the more likely will a weak cell get damaged.

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Lithium Advantages In Your Bass Boat

The anticipation of a morning bite can make it difficult to sleep at night. As you wait for the sun to peak over the horizon you run over everything in your checklist. All your rods are rigged, and you have every bait from a topwater frog to a Texas rigged senko tied on. Every bit of your terminal tackle is stowed perfectly, and you even remembered to pack a lunch. Except that one major piece of the puzzle that you forgot suddenly hits you and you realize that you never charged your trolling motor batteries. Luckily, you made the decision to replace those old lead acid batteries you had for lithium powered batteries and you can be charged up enough by sunrise to salvage the trip. A major sigh of relief for those that live and die by the water and the time they get to spend making cast after cast.

 

Every component of a boat must work together in order for you to create those unforgettable bites that every angler chases. A fault in your boat’s system can quickly turn a picture-perfect day into a nightmare. Often, we think about all the accessories we want to add to our bass boats to make them more functional and to improve our odds of catching those elusive giants, yet we pay less mind to the power plant of our technologies. At Li-ion we want to make it very simple and clear as to why lithium batteries are the best choice for your bass boat.

A bass boat needs reliable marine batteries as they are necessary for both starting and running your fishing machine. Not all batteries serve the same purpose as some are intended specifically for producing cranking power for engine startups and others are used exclusively for running your trolling motor. Essentially, starting batteries discharge a large amount of energy for a short period of time making them perfect for starting your outboard engines. Deep cycle batteries on the other hand, discharge small amounts of energy over an extended period of time. Regardless, lithium batteries offer solutions to every angler’s needs.

 

Time to charge is a major factor of each and every battery. Lithium, however, charges significantly faster than lead acid. Plain and simple. Our lithium batteries can be charged in as fast as an hour, but we recommend using a charge rate that charges them in 2-5 hours. This means that the moment of panic of whether you plugged your batteries in is long gone and you can be confident that you’ll be ready come morning. Some may wonder if leaving the battery in a state of partial charge will damage its performance or overall longevity and quite frankly the answer is, no. Lithium batteries are partial charge tolerant making them perfect for the on the go or maybe even the forgetful angler.

 

At first glance the cost of switching to lithium batteries may seem impractical in comparison to lead acid but when you break down the details, they paint a very different picture. Lithium batteries last up to 10 times longer than their lead acid counterparts and they still provide 80% capacity after 2000 cycles. This means that you don’t have to bring in a forklift every couple of years to haul out those absurdly heavy chunks of lead you have at the stern of your boat (you don’t actually need a forklift but you get the point). It is this same weight that has reduced your fuel economy and your time to plane. Every pound you add to the boat makes you draft that much deeper and can ultimately affect the ride and performance. Lithium batteries have 50-60% less weight than lead acid batteries and in some cases the weight savings from switching to lithium batteries can exceed 100 pounds. This amount of weight taken off your stern will improve both your range and wide-open throttle numbers for those days when you want to hammer down.

 

For the days when the bite rages from dawn to dusk or even the days when you grind it out for that one single bite, lithium power will be with you all the way. Quite simply, lithium has more hours of power. Lithium iron phosphate provides more usable capacity than lead acid. With 25-50% higher capacity than lead acid batteries with full power throughout discharge lithium batteries eliminate the voltage sag that is all too common with lead acid. All your accessories will be uninterrupted, and you can continue to max out that five fish limit you were working on. As the sun begins to drop after a full day on the water you won’t have to worry about anything except coming up with an excuse as to why you couldn’t make it home for your family dinner on time.

 

 

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Series Vs. Parallel Connections Explained

Series Vs. Parallel Connections Explained

 

While researching lithium batteries, you’ve probably seen the terms series and parallel mentioned. We frequently get asked the question, “what’s the difference between series and parallel”, “can Li-ion batteries be connected in series” and similar questions. It can be confusing if you’re new to lithium batteries or batteries in general, but hopefully we can help simplify it.

Let’s start at the beginning…your battery bank. The battery bank is the result of connecting two or more batteries together for a single application (i.e. a sailboat). What does joining more than one battery together accomplish? By connecting the batteries, you either increase the voltage or amp-hour capacity, and sometimes both, ultimately allowing for more power and/or energy.

The first thing you need to know is that there are two primary ways to successfully connect two or more batteries: The first is called a series connection and the second is called a parallel connection.

Series connections involve connecting 2 or more batteries together to increase the voltage of the battery system, but keeps the same amp-hour rating. Keep in mind in series connections each battery needs to have the same voltage and capacity rating, or you can end up damaging the battery. To connect batteries in series, you connect the positive terminal of one battery to the negative of another until the desired voltage is achieved. When charging batteries in series, you need to utilize a charger that matches the system voltage. We recommend you charge each battery individually, with a multi-bank charger, to avoid imbalance between batteries.

In the image below, there are two 12V batteries connected in series which turns this battery bank into a 24V system. You can also see that the bank still has a total capacity rating of 100 Ah.

Parallel connections involve connecting 2 or more batteries together to increase the amp-hour capacity of the battery bank, but your voltage stays the same. To connect batteries in parallel, the positive terminals are connected together via a cable and the negative terminals are connected together with another cable until you reach your desired capacity.

A parallel connection is not meant to allow your batteries to power anything above its standard voltage output, but rather increase the duration for which it could power equipment. It’s important to note that when charging batteries that are connected in parallel, the increased amp-hour capacity may require a longer charge time.

In the example below, we have two 12V batteries, but you see the amp-hours increase to 200 Ah.

Now we get to the question, “Can Li-ion batteries be connected in series or parallel?”

Standard Product Line: Our standard lithium batteries can be wired in either series or parallel based on what you’re trying to accomplish in your specific application. Li-ion’s data sheets indicate the number of batteries that can be connected in series by model. We typically recommend a maximum of 4 batteries in parallel for our standard product, however there may be exceptions that allow for more depending on your application.

It’s important to understand the difference between parallel and series configurations, and the effects they have on your battery bank’s performance. Whether you’re seeking an increase in voltage or amp-hour capacity, knowing these two configurations is vastly important in maximizing your lithium battery’s life and overall performance.

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Choosing The Right Batteries For Your Overland Vehicle

Himax-Golf-car-battery

If you are interested in overland vehicles, it pays to figure out the best way to power it. By taking the time to find the right battery setup for your overland vehicle, you’ll be able to hit the terrain without worry. When you are in need of a new system, these are the tips you’ll need to consider.

Finding the Right Battery Setup for Overland Vehicles

Lithium batteries are used in a number of applications, including marine vehicles, overland vehicles, golf carts and more.

Here’s what you need to know before making a purchase:

 

1.Understand the Specifications

As you research various batteries, you will need to look into its specifications to ensure it’s the right fit for your application and power needs. Learning about each battery’s capabilities will allow you to make the proper choice for your overlanding vehicle.

Each overlanding outfit will have different requirements and for some a single battery unit may be plenty while for others they may require a multi-unit setup for those long trips to the middle of nowhere. Everything must be considered from the weight of the unit to its power output. We understand that the details matter when it comes to exploration and adventure.

2.Consider the Maintenance That Comes with Your Battery

Anytime you’re using batteries on a regular basis, you’ll need to be fully aware of the maintenance that comes with the territory. This means understanding the status of the battery’s power before long trips and making sure that the connections are secure.

 

Thankfully, lithium batteries require virtually no maintenance, so your maintenance costs and obligations will be low. Both on and off-season maintenance is minimal making your experience with lithium worry and stress free. This is yet another reason why they are an excellent investment.

3.Decide on What Power Needs You Have

Quite possibly the most important consideration to make when looking to install a new system or upgrade from your existing battery system is what kind of power you will need.

This will depend on the type of vehicle you own, how often you drive it, and what you may be powering with your lithium deep cycle battery. In terms of voltage, you might purchase batteries that are 12.8 Volts, 25.6 Volts, 51.2 Volts, and other power measurements.

You should also consider amperage and other measurements that come into play when you are in the market for a new battery setup.

When you use deep cycle batteries, they’ll still power your electronic devices when you’re stopped. This is particularly useful when you’re in undeveloped areas with no hookups or access to power sources. Regardless, LiFeP04 batteries offer a solution to every enthusiast’s needs.

Himax-Golf-car-battery

4.Weigh the Pros and Cons of Lead-Acid vs. Lithium

It’s important to think about the features you require in a battery for your expeditions, then decipher which battery chemistry is ideal for your needs.

Lead-acid batteries may still dominate the market, but many overland adventurers are moving to lithium batteries instead because they’re a superior alternative to traditional batteries. The benefits of choosing LiFePO4 over lead-acid for any application are numerous. And, when it comes to your overland vehicle, there are specific advantages that make lithium overland batteries the ideal choice. They weigh less, offer more usable capacity, they’re safe and they have a much longer life cycle, up to ten times longer. Lead-acid, on the other hand, can weigh twice as much as lithium and requires far more maintenance while still producing less usable capacity over its range. Lithium out performs lead-acid in nearly every category and is an excellent long term investment for those looking to get off the grid.

5.Decide How Much You Want to Pay

Of course, you will need to consider the price whenever you are in the market for a new battery setup.

There are several types of batteries, including FLA, GEL, AGM and LiFePO4, so it pays to figure out your budget in advance, while also having an idea of how much one of these new batteries will cost you. While lithium batteries have a higher upfront cost, the true cost of ownership is far less than lead-acid when considering life span and performance. Changing batteries less often means fewer replacement and labor costs. These savings make lithium batteries a more valuable long-term investment than lead-acid batteries.

If you are going to have a repair shop handle the installation, be sure to get cost estimates of both the battery itself and the labor for the installation.

 

6.Consider Waterproofing and Other Protective Features

Finally, make sure that you get a listing of all the features that come with the battery.

A number of overland battery setups come with waterproofing, which will protect it from rain and changes in moisture. You’ll want to buy a battery that has thickly insulated, anti-corrosive cables as well. This will allow you to keep the battery intact and flowing with the current.

See what connectors it comes with and see if you can trade-in your old battery before buying a new one.

RV-Car-Battery

Buy the Perfect Battery for Your Overland Vehicle

When you consider a battery setup for overland vehicles, these are the tips you need to be aware of.

We’ve got you covered when you are in the market for any kind of battery setup that you need.

Consider these tips and buy a deep cycle lithium battery that is perfect for your overland adventures.

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The Best Golf Cart Batteries: Lithium Vs. Lead Acid

car-battery

The golf cart market is evolving as more and more people are taking advantage of their versatile performance. For decades, deep-cycle flooded lead-acid batteries have been the most cost effective means to power electric golf cars. With the rise of lithium batteries in many high-power applications, many are now looking into the advantages of LiFePO4 batteries in their golf cart.

While any golf cart will help you get around the course or neighborhood, you need to make sure it has enough power for the job. This is where lithium golf cart batteries come into play. They’re challenging the lead-acid battery market due to their many benefits that make them easier to maintain and more cost-effective in the long run.

Below is our breakdown of the advantages of lithium golf cart batteries over lead-acid counterparts.

48v-ev-battery

Carrying Capacity

Equipping a lithium battery into a golf cart enables the cart to significantly increase its weight-to-performance ratio. Lithium golf cart batteries are half the weight of a traditional lead-acid battery, which shaves off two-thirds of the battery weight a golf cart would normally operate with. The lighter weight means the golf cart can reach higher speeds with less effort and carry more weight without feeling sluggish to the occupants.

 

The weight-to-performance ratio difference lets the lithium-powered cart carry an additional two average-sized adults and their equipment before reaching carrying capacity. Because lithium batteries maintain the same voltage outputs regardless of the battery’s charge, the cart continues to perform after its lead-acid counterpart has fallen behind the pack. In comparison, lead acid and Absorbent Glass Mat (AGM) batteries lose voltage output and performance after 70-75 percent of the rated battery capacity is used, which negatively affects carrying capacity and compounds the issue as the day wears on.

 

No Maintenance

One of the major benefits of lithium batteries is that they require no maintenance whatsoever, whereas lead-acid batteries regularly need to be checked and maintained. This ultimately results in saved man hours and the extra costs of maintenance tools and products. The lack of lead-acid means that chemical spills are avoided and the chance of downtime on your golf car is drastically reduced.

 

Battery Charging Speed

Regardless if you’re using a lead-acid battery or a lithium battery, any electric car or golf cart faces the same flaw: they have to be charged. Charging takes time, and unless you happen to have a second cart at your disposal, that time can put you out of the game for a while. A good golf cart needs to maintain consistent power and speed on any course terrain. Lithium batteries can manage this without a problem, but a lead-acid battery will slow the cart down as its voltage dips. Plus after the charge has dissipated, it takes an average lead-acid battery roughly eight hours to recharge back to full. Whereas, lithium batteries can be recharged up to 80 percent capacity in about an hour, and reach full charge in less than three hours.

 

Plus, partially-charged lead-acid batteries sustain sulfation damage, which results in significantly reduced life. On the other hand, lithium batteries have no adverse reaction to being less than fully charged, so it’s okay to give the golf cart a pit-stop charge during lunch.

72V 200Ah

Eco-Friendly

Lithium batteries put less strain on the environment. They take significantly less time to fully charge, resulting in using less energy. They do not contain hazardous material, whereas lead-acid batteries, as the name suggests, contain lead which is harmful to the environment.

 

Battery Cycle Life

Lithium batteries last significantly longer than lead-acid batteries because the lithium chemistry increases the number of charge cycles. An average lithium battery can cycle between 2,000 and 5,000 times; whereas, an average lead-acid battery can last roughly 500 to 1,000 cycles. Although lithium batteries have a high upfront cost, compared to frequent lead-acid battery replacements, a lithium battery pays for itself over its lifetime. Not only does the investment in a lithium battery pay for itself over time, but big savings can be made in the way of reduced energy bills, maintenance costs, and possible repairs that would otherwise need to be made to heavy lead-acid golf cars. They also just perform better overall!

 

Are Lithium Golf Cart Batteries Compatible?

Golf carts designed for lead-acid batteries can see a significant performance boost by swapping the lead-acid battery to a lithium battery. However, this second wind can come at an instillation cost. Many lead-acid equipped golf carts need a retro-fit kit to operate with a lithium battery, and if the cart manufacturer doesn’t have a kit, then the cart will need modifications to operate with a lithium battery.

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New Technique Produces Longer-lasting Lithium Batteries

Date:APRIL 22, 2019

Source:Columbia University School of Engineering and Applied Science

An artificial boron nitride (BN) film is chemically and mechanically robust against lithium. It electronically isolates lithium aluminum titanium phosphate (LATP) from lithium, but still provides stable ionic pathways when infiltrated by polyethylene oxide (PEO), and thus enables stable cycling. Credit: Qian Cheng/Columbia Engineering

The grand challenge to improve energy storage and increase battery life, while ensuring safe operation, is becoming evermore critical as we become increasingly reliant on this energy source for everything from portable devices to electric vehicles. A Columbia Engineering team led by Yuan Yang, assistant professor of materials science and engineering, announced today that they have developed a new method for safely prolonging battery life by inserting a nano-coating of boron nitride (BN) to stabilize solid electrolytes in lithium metal batteries. Their findings are outlined in a new study published by Joule.

 

While conventional lithium ion (Li-ion) batteries are currently widely used in daily life, they have low energy density, resulting in shorter battery life, and, because of the highly flammable liquid electrolyte inside them, they can short out and even catch fire. Energy density could be improved by using lithium metalto replace the graphite anode used in Li-ion batteries: lithium metal’s theoretical capacity for the amount of charge it can deliver is almost 10 times higher than that of graphite. But during lithium plating, dendrites often form and if they penetrate the membrane separator in the middle of the battery, they can create short-circuits, raising concerns about battery safety.

“We decided to focus on solid, ceramic electrolytes. They show great promise in improving both safety and energy density, as compared with conventional, flammable electrolytes in Li-ion batteries,” says Yang. “We are particularly interested in rechargeable solid-state lithium batteries because they are promising candidates for next-generation energy storage.”

Most solid electrolytes are ceramic, and therefore non-flammable, eliminating safety concerns. In addition, solid ceramic electrolytes have a high mechanical strength that can actually suppress lithium dendrite growth, making lithium metal a coating option for battery anodes. However, most solid electrolytes are unstable against Li—they can be easily corroded by lithium metal and cannot be used in batteries.

The left visual shows that a Lithium aluminum titanium phosphate (LATP) pellet that touches lithium metal will be immediately reduced. The severe side reaction between lithium and solid electrolyte will fail the battery in several cycles. The right shows that an artificial BN film is chemically and mechanically robust against lithium. It electronically isolates LATP from lithium, but still provides stable ionic pathways when infiltrated by polyethylene oxide (PEO), and thus enables stable cycling. Credit: Qian Cheng/Columbia Engineering

 

“Lithium metal is indispensable for enhancing energy density and so it’s critical that we be able to use it as the anode for solid electrolytes,” says Qian Cheng, the paper’s lead author and a postdoctoral research scientist in the department of applied physics and applied mathematics who works in Yang’s group. “To adapt these unstable solid electrolytes for real-life applications, we needed to develop a chemically and mechanically stable interface to protect these solid electrolytes against the lithium anode. It is essential that the interface not only be highly electronically insulating, but also ionically conducting in order to transport lithium ions. Plus, this interface has to be super-thin to avoid lowering the energy density of batteries.”

 

To address these challenges, the team worked with colleagues at Brookhaven National Lab and the City University of New York. They deposited 5~10 nm boron nitride (BN) nano-film as a protective layer to isolate the electrical contact between lithium metal and the ionic conductor (the solid electrolyte), along with a trace quantity of polymer or liquid electrolyte to infiltrate the electrode/electrolyte interface. They selected BN as a protective layer because it is chemically and mechanically stable with lithium metal, providing a high degree of electronic insulation. They designed the BN layer to have intrinsic defects, through which lithium ions can pass through, allowing it to serve as an excellent separator. In addition, BN can be readily prepared by chemical vapor deposition to form large-scale (~dm level), atomically thin scale (~nm level), and continuous films.

“While earlier studies used polymeric protection layers as thick as 200 μm, our BN protective film, at only 5~10 nm thick, is record-thin—at the limit of such protection layers—without lowering the energy density of batteries,” Cheng says. “It’s the perfect material to function as a barrier that prevents the invasion of lithium metal to solid electrolyte. Like a bullet-proof vest, we’ve developed a lithium-metal-proof ‘vest’ for unstable solid electrolytes and, with that innovation, achieved long cycling lifetime lithium metal batteries.”

The researchers are now extending their method to a broad range of unstable solid electrolytes and further optimize the interface. They expect to fabricate solid-state batteries with high performance and long-cycle lifetimes.

A New Material For The Battery Of The Future

Researchers have discovered a new high performance and safe battery material (LTPS) capable of speeding up charge and discharge to a level never observed so far. Practically, if the first tests are confirmed, this new material could be used in the batteries of the future with better energy storage, faster charge and discharge and higher safety targeting many uses from smartphones, to electric bicycle and cars.

Renewable sources of energy such as wind or photovoltaic are intermittent. The production peaks do not necessarily follow the demand peaks. Storing green energy is therefore essential to moving away from fossil fuels. The energy produced by photovoltaic cells is stored during the day and by wind-power when the wind blows to be used later on when needed.

What do we have now?

The Li-ion technology is currently the best performing technology for energy storage based on batteries. Li-ion batteries are used in small electronics (smartphones, laptops) and are the best options for electric cars. Their drawback? Li-ion batteries can catch fire, for instance because of a manufacturing problem. This is due in part to the presence of liquid organic electrolytes in current batteries. These organic electrolytes are necessary to the battery but highly flammable.

The solution? Switching from a liquid flammable electrolyte to a solid (i.e., moving to ” all-solid-state ” batteries). This is a very difficult step as lithium ions in solids are less mobile than in liquids. This lower mobility limits the battery performances in terms of charge and discharge rate.

The discovery made by UCLouvain

Scientists have been looking for materials that could enable these future all-solid-state batteries. Researchers from UCLouvain recently discovered such material. Its name? LiTi2(PS4)3 or LTPS. The researchers observed in LTPS the highest lithium diffusion coefficient (a direct measure of lithium mobility) ever measured in a solid. LTPS shows a diffusion coefficient much higher than known materials. The results are published in the scientific journal Chem from Cell Press.

The discovery? This lithium mobility comes directly from the unique crystal structure (i.e., the arrangement of atoms) of LTPS. The understanding of this mechanism opens new perspectives in the field of lithium ion conductors and, beyond LTPS, opens an avenue towards the search for new materials with similar diffusion mechanisms.

What’s next? The researchers need for further study and improve the material to enable its future commercialization. This discovery is nevertheless an important step in the understanding of materials with extremely high lithium ion mobility which are ultimately needed for the developing the “all-solid-state” batteries of the future. These materials including LTPS might end up being used in many the technologies that we use in our daily lives from cars to smartphones.

This research was performed in collaboration with Toyota, which supported scientifically and financially the study. A patent has been filed listing the UCLouvain researchers as inventors.

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Transport of Lithium Batteries According to UN 38.3

UN38.3 Battery

Anyone who has ever dealt with lithium batteries knows the demanding process for transportation. Lithium cells and batteries are classified as dangerous goods class 9 and thus are on a par with liquid nitrogen. The requirements for safe transport are correspondingly high.

Whether by rail, road or air, the eligibility of lithium cell or battery shipments is regulated by the transport test 38.3 of the United Nations. A shipment is only permitted if the following eight individual tests are passed.

UN38.3 Battery

1) Altitude Simulation

This test simulates the environmental conditions prevailing in the cargo hold of an aircraft at an altitude of up to 15,000 meters. The battery is exposed to an extremely low air pressure of 11.6 kilopascal for a total of six hours. The test is passed if:

 

the battery shows no loss of mass

the overpressure valve of the battery remains closed

the battery housing is free of cracks or leaks,

the voltage level of the battery differs from the initial value by a maximum of 10% after completion of the test.

2) Thermal Test

If the altitude simulation has been successfully completed, the next step is to check the behavior of the lithium battery in case of strong temperature fluctuations. This stresses the battery seals and internal electrical connections. The batteries are initially stored for at least six hours at a surrounding temperature of 72 degrees Celsius. The temperature is then lowered to -40 degrees Celsius for a further six hours. This test procedure, for which Jauch uses a specially designed thermal shock chamber, must be carried out over 10 complete cycles. Finally, the batteries are stored at room temperature for at least another twelve hours. The test is passed when all the criteria mentioned under 1) have been met.

 

3) Vibration Test

The third part of the UN 38.3 transport test puts the battery in a vibration generator, where the battery is subjected to frequencies between 7 and 200 Hertz. The test is designed for a total of three hours and simulates the typical jerking in the hold of a truck while driving. The criteria mentioned under 1) also apply in this case.

 

4) Impact Test

Just like the vibration test, the impact test also serves to prevent possible damage to the battery by rough transport. Depending on the size of the lithium battery, impacts of 150G/6mS or 50G/11mS affect the housing. Just as in the vibration test, the criteria listed under 1) apply here as well.

 

5) External Short Circuit Test

For this test, the battery is first heated from the outside to a temperature of 57 degrees Celsius before an external short-circuit is caused. As a result, the battery temperature rises, but must not exceed 170 degrees Celsius. Once the battery has cooled down to 57 degrees again, the short-circuit condition must remain for another 60 minutes. The test is only passed if neither flames, cracks nor other damage to the battery housing are detected for up to six hours afterwards.

 

6) Impact and Crush Test

This test is carried out at cell level and simulates external damage to the cells that can occur because of a strong impact, such as a traffic accident. For this purpose, depending on the cell type and shape, a stamp with a precisely defined size and press depth is pressed into the cells. Damaged in this way, an internal short-circuit can occur in the cell. The test is passed if, as with the external short-circuit test, the housing temperature does not exceed 170 degrees Celsius at any time and no signs of cracks or similar appear on the housing up to six hours after the test.

 

7) Overcharging Test

The UN 38.3 transport test prescribes an overcharge test for all rechargeable lithium batteries. For 24 hours, twice the maximum permissible charging current is applied to the battery. The battery must then be stored in a secure area for seven days. No damage may occur during this period for the battery to pass.

 

8) Fast Discharge Test

The final test is also carried out at cell level. The cell is subjected to a discharge current exceeding the permitted maximum. This procedure is repeated several times. As with overcharging, rapid discharge must not damage the battery in any way in order to successfully pass this test.

 

According to UN 38.3, a battery may not be shipped by rail, road or air until it has passed each of these eight test procedures.

6 Important Parameters for the Design-In of Lithium Polymer Batteries

3.7V Lipo battery

3.7V Lipo battery

A standardized battery fits into any compatible compartment –after all, that’s why standards are defined. Depending on the application, however, button cells and cylindrical batteries reach their limits.

 

A Smartwatch, for example, has a significantly higher energy consumption than an ordinary wristwatch. A simple button cell is therefore far from sufficient to cover the device’s power requirements. However, the case of the watch is far too small for a powerful lithium-ion battery. Only a lithium polymer battery is capable of meeting the specific requirements of a Smartwatch.

 

Flexible product design

Lithium polymer technology is a match to lithium ion batteries in terms of performance, but is much more flexible in terms of design and size. The reason for this is the absence of a solid metal housing, as is common with lithium-ion batteries. Instead, the cells are merely enclosed by a thin layer of plastic-laminated aluminum foil. Thanks to the sandwich-like structure of the battery cells, even curved or ultra-flat designs with a thickness of less than one millimeter are conceivable.

 

For product developers and designers, the great flexibility of Lithium-Polymer batteries is a blessing. Conversely, the new design freedom can also lead to uncertainty. It is therefore advisable to take battery developers such as Jauch Quartz GmbH on board at an early stage for new developments.

 

The following six parameters must be defined at an early stage if design-in is to be successful.

 

1) Voltage

The average single cell voltage for lithium polymer cells is 3.6 volts as standard. The switch-off voltage is 3.0 volts and the maximum charging voltage is 4.2 volts. If a higher voltage is required, several cells can be connected in series. A parallel connection of several cells also makes it possible to increase the capacity.

 

2) Currents

In addition to the voltage, the current requirement of the application must also be defined. The average continuous currents must be specified as well as the maximum pulse currents and pulse lengths. The inrush currents and their lengths must also be taken into account.

 

3) Temperature

In connection with the current power load profiles of the application, the temperatures at which they are used must also be taken into consideration. By default, lithium polymer cells are designed for a temperature range between -20 and 60 degrees Celsius. Temperatures between 0 and 45 degrees Celsius should prevail when charging the cells.

 

Special cells are available for use under extreme temperature conditions above or below this range.

 

4) Dimensions of the Battery Compartment

Of course, the dimensions of the battery compartment must also be defined in advance. It is important to remember that lithium polymer cells expand over time. This “swelling” phenomenon is responsible for the cells to become up to 10% thicker over time. Accordingly, the battery compartment should be generously dimensioned. In addition, sharp edges or the like in the immediate vicinity of the battery compartment must be avoided at all costs so that the battery is not damaged.

 

5) Capacity

The capacity of a battery indicates the amount of electrical charge that a battery can store or release. Capacity is determined by voltage, current consumption, temperature and the available space in the battery compartment.

 

6) Safety

To protect lithium polymer batteries from overcharging, deep discharge or short circuits, they are equipped with individually programmable protection electronics. In order to optimally adapt this so-called “battery management system” to the respective application, individual switch-off values for the system are defined.

 

In addition, batteries must meet certain norms and safety standards to ensure that the applications are approved. Strict regulations apply here – understandably – especially in the field of medical technology.

 

Based on these six parameters, Jauch’s battery experts will find the right lithium polymer battery solution for every application. In order to guarantee optimum results, however, contact should be made as early as possible in the design-in phase. Otherwise, the desired battery solution may not be available or feasible.

 

In addition to these six parameters, there are many other factors that play a role in the selection of the optimum lithium polymer battery solution.

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LITHIUM BATTERIES: CYLINDRICAL VERSUS PRISMATIC

By and large, lithium batteries bring a wide range of different benefits to the table that are difficult – if not impossible – to replicate in any other way. Also commonly referred to as lithium-metal batteries (due to the fact that they use lithium as an anode), they’re typically capable of offering a very high-charge density (read: longer lifespan) than other alternatives that are on the market today.

For that reason alone, lithium batteries have a wide range of applications in our daily lives, especially for those critical in nature that we tend not to spend too much time thinking about. Specialized types of lithium batteries are used in pacemakers and other implanted medical devices, for example, because they can often last 15 years (or longer) under the right circumstances. They’ve even started to replace traditional alkaline batteries in many everyday devices like clocks, digital cameras, watches, portable data assistants, and more, all thanks to that longer lifespan that minimizes the need to replace the battery over time.

LITHIUM BATTERIES: CYLINDRICAL VERSUS PRISMATIC

Example of cylindrical lithium batteries.

Issues like mechanical vibrations, thermal cycling from charging and discharging, and the mechanical expansion of current conductors are all things that can affect a battery’s lifespan. Therefore, the design of these cylindrical units is intended to help mitigate risk from these and other factors as much as possible.

 

On the inside of a cylindrical battery, a series of cells are combined and operate in parallel to one another. This is done to help increase both the voltage and the overall capacity of the battery pack.

 

For these reasons, cylindrical batteries are usually the kind that are found in the aforementioned medical device systems. Smaller, more specially designed cylindrical cells are also commonly found in portable devices like laptop computers. Notably, Tesla also made headlines recently by selecting cylindrical lithium batteries to power its fleet of popular electric cars.

 

What Are Prismatic Lithium Batteries?

A prismatic lithium battery, on the other hand, features a cell that has been encased in either aluminum or steel, mainly for the purposes of increased stability. This, in turn, creates several key advantages right out of the gate. Because of this unique construction and makeup, prismatic lithium batteries tend to be very thin, very light and offer an effective use of space.

Example of prismatic lithium batteries.

 

Because the rectangular shape of your average prismatic Li battery offers far better layering than other options, they typically give engineers a higher level of flexibility when designing products that will one day feature prismatic batteries as power sources. Because of that, it should come as no surprise that prismatic batteries are typically found in smartphones, tablets, and similar types of electronic devices where mobility is a major priority.

 

Due to these properties, modern day prismatic batteries are also commonly used in larger critical applications like energy storage systems and in electric powertrains.

 

Cylindrical Versus Prismatic Batteries: Breaking Things Down

There’s a reason why cylindrical lithium batteries are the most commonly available (and used) type today. When compared to their prismatic counterparts, they can typically be produced much faster and with a lower cost-per-KWh (kilowatt hour) at the same time. The design itself better supports the types of automation processes that are commonplace in factories and in other manufacturing environments across the country, for example, which only aid in creating a better sense of product consistency and keeping those ultimate costs as low as possible.

 

One of the major reasons why prismatic cells have increased in popularity over the last few years, however, has to do with their large capacity. That, coupled with their naturally prismatic shape, make it very easy to connect four different cells together to help create something like a 12-volt battery pack.

 

The prismatic design does come with its own challenges, however, particularly as they relate to what happens if something goes wrong. If one cell in a prismatic battery goes bad for any reason, for example, the entire battery pack that it is a part of is essentially compromised. Because the cells in a cylindrical battery are combined in a series and in parallel, these are the types of problems that designers and other engineers don’t really have to worry about.

 

Because of the design of cylindrical Li batteries, they also tend to radiate heat (and thus control their own temperature) more easily than their prismatic counterparts. Because of the way that prismatic cells are all placed together, this certainly works to increase the capacity, but it also leaves room for a higher probability of design inconsistency and short circuiting. The larger size of the prismatic cell may also be attractive in certain situations, but it also minimizes the chances that such a battery could be used in a heavily automated environment. That larger cell size also creates perhaps the biggest disadvantage for prismatic batteries: the increased capacity makes it far more difficult for the battery management system to properly regulate heat and prevent the battery itself from overcharging.

 

As previously stated, the thin form factor of a prismatic battery leads to increased flexibility for product designers – this does, however, create a few disadvantages of its own. It is that very same design that ultimately makes prismatic batteries somewhat difficult and expensive to properly design and manufacturer, which are costs that are almost certainly passed along to consumers. That flexibility has also created a limited number of “standardized” cell sizes, which only adds to difficulty in that regard. This also contributes to a higher than average KWh price as well.

 

It’s important to note, however, that the topic of costs is also one that comes with a few important caveats. Experts agree that because prismatic cells can often be larger than their cylindrical counterparts and will thus cost more initially, they offer more opportunity for cost reduction in the long-term. Based on that, you may want to think about the cost factor in the following way: is it more important to save money now by going cylindrical, or can you depend on your ability to innovate and potentially save a larger amount of money over time? The answer to that question, of course, is one that only you can answer based on whatever it is you’re trying to do.

 

Maybe the biggest advantage of cylindrical batteries in most situations is that they are very safe. If the internal pressure of a cylindrical lithium battery grows too high, most of the cells are designed to rupture – thus mitigating safety risks from situations like a fire or an explosion.

 

In The End

None of this is to say that cylindrical lithium batteries are inherently “better” than their prismatic counterparts, or vice versa. As is often the case with these types of situations, there is no “one-size-fits-all” approach to battery selection. Much of your decision will ultimately come down to the eventual application and the amount of risks and potential disadvantages that you’re willing to accept as a result. There will be some situations where a prismatic battery absolutely makes the most sense. There will be situations where cylindrical batteries seem like the logical choice.

 

More often than not, choosing the right type of lithium battery to meet your needs will come down to three factors:

 

The amount of money you’re willing to pay, the effectiveness of the battery you’re trying to unlock, and the safety considerations given the application.

If space isn’t necessarily at a premium and you need to find a cost-effective way to guarantee both performance and longevity, cylindrical batteries offer what you need.

If cost isn’t a factor and you need as much power as possible in an already small space, prismatic is likely the direction you’ll want to head in.

Only by trying to learn as much about these options as possible will you be able to make the best decision given your needs in the moment. Ultimately, your ability to do that successfully is all that matters.