Advantages and Disadvantages of Ternary Power Lithium Batteries

Lithium is the lightest metal with high specific energy, and it has the smallest atomic mass (its atomic weight is 6.94g/mol, ρ=0.53g/cm3).

A ternary power lithium battery is a lithium secondary battery that uses nickel-cobalt-manganese, three transition metal oxides, as the cathode material. It integrates the good cycling performance of lithium cobaltate, the high specific capacity of lithium nickelate, and the high safety and low cost of lithium manganese.

Ternary power lithium battery also synthesizes the synergistic composite inlaid lithium oxide, such as nickel-cobalt-manganese, using molecular level mixing, wrapping, and surface modifications. the ternary power lithium battery is a type of lithium-ion rechargeable battery that is widely studied and used.

Ternary power lithium battery life

Lithium battery life refers to the battery after a period of use specifically when the capacity of the battery has decayed to 70% of the nominal capacity (at room temperature 25 ℃, standard atmospheric pressure, and battery capacity discharged at 0.2C). The industry generally calculates the cycle life of a lithium battery by the number of full discharge cycles.

Over the course of use, lithium batteries undergo irreversible electrochemical reactions inside the battery, leading to a decrease in capacity, such as the breakdown of the electrolyte, the inactivation of the active material, the collapse of the positive and negative electrode structure, resulting in a decrease in the number of lithium ions embedded and de-embedded, etc.

Experiments have shown that higher-magnification discharges lead to faster capacity decay, and if the discharge current is lower, the battery voltage will be closer to the equilibrium voltage, which can release more energy.

The theoretical life of a lithium battery is about 800 cycles, which is moderate among commercially available rechargeable lithium batteries. Lithium iron phosphate is about 2,000 cycles while lithium titanate is said to reach 10,000 cycles.

Battery manufacturers promise more than 500 cycles under standard conditions in the specifications of their ternary batteries, but, due to consistency problems (the voltage and internal resistance can not be exactly the same), its cycle life is about 400 cycles. Manufacturers recommend the use of a SOC window of 10-90%, is not recommended for deep charge and discharge as it may cause irreversible damage to the positive and negative structure of the battery. In addition, if the lithium battery is frequently discharged in high magnification and high-temperature environment, the battery life can reduce to less than 200 cycles.

Ternary power lithium battery material

The ternary power lithium battery is a comprehensive and excellent battery with a balanced capacity and safety. The main roles, advantages, and disadvantages of the three metal elements are as follows:

Co3+ reduces cationic mixing occupancy, stabilizes the laminar structure of the material, reduces impedance value, improves conductivity, and improves cycling and multiplication performance.

Ni2+ can improve the capacity of the material (improve the volumetric energy density of the material); however, because lithium and nickel have a similar radius, too much nickel will also cause the dislocation phenomenon with lithium, resulting in lithium-nickel mixing. The greater the concentration of nickel ions in the lithium layer, the more difficult the lithium in the laminar structure, resulting in poor electrochemical performance.

Mn4+ not only reduces material costs but also improves the safety and stability of the material. However, too much Manganese will make the battery prone to the emergence of the spinel phase and destroy the laminar structure, resulting in reduced capacity and cyclic decay.

Ternary power lithium battery energy density

When compared to lithium iron phosphate, lithium manganate, or lithium titanate, high energy density is the biggest advantage of ternary lithium batteries. The voltage platform is an important indicator of the battery energy density, which determines the basic performance and cost of the battery. The higher the voltage platform, the larger the capacity.

The discharge voltage platform of a single ternary lithium battery is as high as 3.7V, 3.2V for lithium iron phosphate, and only 2.3V for lithium titanate, so, in terms of energy density, the ternary lithium battery has an absolute advantage over lithium iron phosphate, lithium manganate or lithium titanate.

Poor safety and short cycle life are the main shortcomings of ternary lithium batteries. Safety performance has especially been a major factor limiting its large-scale packaging and large-scale integrated applications. The 500-cycles cycle life in a lithium battery is medium to low, so the ternary lithium battery is the most important application field in 3C digital and other consumer electronics.

If you are interested in a ternary power lithium battery, please don’t hesitate to contact us at any time.
Email: info@grepow.com
Grepow Website: https://www.grepow.com/

How to Replace a Bluetooth Speaker’s Battery?

When choosing a Bluetooth speaker, battery life is very important, which is about how long you can use it outside(it can be used outside). If the battery life is short, it is not suitable for outdoor use. This battery life is related to the capacity of the Bluetooth battery. So are the battery capacities of the Bluetooth speakers real? How can we replace the battery of the Bluetooth speaker?

Bluetooth speaker battery capacity

People seek long-term battery life of Bluetooth speakers, so the requirements on Bluetooth battery capacity will be higher.

If you don’t unpack or test, how do you know if the Bluetooth battery capacity or endurance time is real? At this time, you can acquire the fact.  For example, a 500mA to 800mA Bluetooth speaker, its battery life usually is 3 to 5 hours.

It is also possible to calculate whether the battery capacity of the Bluetooth speaker is real. Battery capacity equals to using time multiplied by device power and then divided by the battery voltage. So we can calculate how many capacities of the battery when we buy a Bluetooth speaker.

How to replace the battery?

The battery of electronic products becomes less useful after the long run using, and the working time is greatly reduced. If you buy a Bluetooth speaker again, it may not be cost-effective. At this time, it is better to replace the battery of the Bluetooth speaker. (It could be more economical if you replace the battery instead of buying a new Bluetooth.)

Turn the bottom of the Bluetooth speaker upwards, tear off its anti-slip mat, you can see the maintained screw, remove it and unscrew it, and then use a soldering iron to heat and make battery on the audio motherboard drop off. Finally, new cables and matching plugs should be soldered together.

After the other end of the wire is welded to anode and cathode of the audio motherboard, fix the wire to it with double-sided tape. The two ends of the Bluetooth battery wire are respectively covered with tape. At this time, you can place the motherboard on the new battery. Close the bottom cover of the speaker, screw the screws back, and then stick double-sided adhesive to the bottom of the speaker, just stick the anti-slip mat back.

The above is how to replace the battery of a Bluetooth speaker. When buying a Bluetooth speaker, pay attention to whether the capacity of the Bluetooth battery and the endurance time is real. If it is a fake mark, the product quality is certainly not good.

Related Articles:

How to Charge a Bluetooth Headset Correctly?

How Long Does Bluetooth Headset Battery Last?

The Best Bluetooth Headset Battery Manufacturer in China

How to Increase Bluetooth Headset Battery Life?

GREPOW’s Solution For Batteries of Bluetooth Headsets

If you want your Bluetooth battery, please contact us at info@grepow.com

More information: www.grepow.com/page/shaped-battery.html

Will the Bluetooth Headset Battery Explode?

Is there any guarantee for the safety performance of the Bluetooth headset battery? It is not fun to explore on ears.

Bluetooth headset type

Bluetooth headphones can be divided into three categories:

1. Mono

The single-channel Bluetooth headset is a single ear headset. It is mostly wireless and small style. It can be inserted directly into the ear. Its main function is to listen and hang the phone. It can control the volume, and the single ear type Bluetooth headset also has double, double, and rye techniques.

2. Stereophonic

Stereo headphones are based on smartphone support for A2DP Bluetooth stereophonic protocol. Only our mobile phone settings support A2DP Bluetooth stereophonic protocol, and you can connect stereo Bluetooth headphones to enjoy Bluetooth headset music. Stereo Bluetooth headset has neck hanging, headset, clip, glasses, and other styles, lyrics, and other functions.

3. Real wireless

The real wireless Bluetooth headset is very different from the traditional Bluetooth headset. The real wireless Bluetooth headset is based on the Multiplexlink multi-point wireless interconnect technology. The wireless connection between the left and right ears is realized, and the way of wire connection is completely abandoned, and the left and right earplugs can work independently.

Next, we are going to talk about the safety of the Bluetooth headset battery.

Bluetooth headset battery

First of all, the function of the latest version 2.1 of Bluetooth is achieved by saving the power consumption by setting the interval between the 2 devices to confirm the sending interval of signals. In general, when 2 connected Bluetooth devices are in the standby state, the Bluetooth devices still need to make sure that they are still in the online state through each other. Of course, because of this, the Bluetooth chip must keep the Bluetooth headset at any time, even if all the other components of the cell phone have entered. Dormant mode. In order to improve this situation, Bluetooth 2.1 prolongs the interval between the signal transmission time between the old version of the device from 0. to 0.5 seconds from the old version, so that the workload of the Bluetooth chip can be greatly reduced, and the Bluetooth can have more time to sleep completely. According to the official report, after this technology is used, the standby time of Bluetooth device can be effectively extended by more than 5 times after the Bluetooth connection is opened. Such a Bluetooth headset lithium polymer battery is in a state of low power consumption, and there will be no safety considerations.

At present, the market for Bluetooth headset batteries is made of lithium polymer batteries. GREPOW also produces the lithium polymer batteries used in Bluetooth products (common models include 150mAh, 60mAh, 30mAh, 75mAh, 90mAh). Compared with the liquid lithium-ion battery, this kind of lithium-ion battery is not only safe, but also has the advantages of thinning, arbitrary area and arbitrary shape, and the shell also uses a lighter aluminum-plastic composite film. However, there may be room for improvement in its low-temperature discharge performance. But at the moment, it is still the main body of the lithium headset of Bluetooth headset. Its advantages are small size, lightweight, large capacity, and so on.

Now our domestic lithium polymer battery is mostly only a flexible packaging battery, the shell is made of aluminum-plastic film, and the electrolyte has not changed. The lithium-polymer battery can also be thinned, and its low-temperature discharge characteristics are better than that of the polymer battery, while the material energy density is basically the same as that of the liquid lithium battery and the ordinary polymer battery, but because of the aluminum-plastic film, it is lighter than the ordinary liquid lithium. In safety, when the liquid is just boiling, the aluminum-plastic film of the soft battery will naturally burst or burst, and it will not explode.

• Contact us for more Bluetooth headset batteries at info@grepow.com
•  lithium polymer battery:  https://www.grepow.com/page/lipo-battery.html
• Bluetooth headset batteries：https://www.grepow.com/page/bluetooth-headset-battery.html

Overcharging Lithium-ion Polymer Batteries

There are many advantages to using Lithium-Ion Polymer (LiPo) batteries: High working voltage, high energy density, long cycle life, low self-discharge rate, and no memory effect.  To fully utilize these aspects of LiPo batteries, users should aim to prolong the life of their batteries.  In order to do so, LiPo batteries should not be overcharged or discharged as explored in this article.

Activating LiPo Batteries

Some may have heard that new LiPo batteries need to be “activated” and thus charged for more than 12 hours.  This is sometimes commonly heard amongst people who have new mobile devices and consequently drain and charge their battery for 12 hours.  This might have been true when Nickel batteries, such as Nickel-metal Hydrogen (NIMH) or Nickel Cadmium (NiCd) batteries, were the predominant power source for mobile devices; however, most mobile devices now use Lithium-ion batteries.  Users do not need to drain and charge their mobile devices in such a manner anymore.

Do batteries need to be activated?  Yes, but this process is completed by the manufacturer and has nothing to do with the user having to do so.  The actual process involves charging the batteries at 0.02C and then charging them in standard charge and discharge cycles to check for certain standards, such as the internal resistance, voltage retention, and maximum capacity.

Overcharging

One of the most common ways that LiPo batteries are abused is in how people overcharge their batteries.  If users leave their batteries charged for too long, the batteries can become damaged, performance can be lost, and the life span of the batteries can decrease.

Fortunately, there are many chargers that automatically stop charging a Lithium-ion battery when the battery is fully charged.  However, there are some devices that do not stop on their own, so users should exercise caution in order to prolong the life of their batteries.  Ultimately, shallow charge and discharge are beneficial to LiPo batteries.

There are also safety concerns especially when users use Lithium-ion batteries incorrectly.  They can become too hot if they are overcharged  As shown by the many videos online, explosions can even occur if users are not careful.  Users should refer back to the instructional and cautionary guidelines behind the products that they are using.

For more battery information, please visit our website: https://www.grepow.com/

The Charging Cycles of Lithium-ion Polymer Batteries

Lithium batteries, or Lithium-ion Polymer (LiPo) batteries, are batteries that use Lithium as a negative electrode material and use a non-aqueous electrolyte solution. In 1912, Lithium metal batteries were first proposed and studied by Gilbert N. Lewis. In the 1970s, M.S. Whittingham proposed and started researching Lithium-ion batteries. However, due to the complications of using the unstable Lithium metal, the batteries were not popular at the time.

It is now with further development that Lithium-ion Polymer batteries have fast become a preferred power source for many applications and industries.  It is for this reason that we will explore the charging cycles of lithium-ion polymer batteries in-depth in this article.

What is a charging cycle?

Some consumers may have that the charge and discharge life of lithium-ion polymer batteries is “500 times.” But what is “500 times?” It refers to the number of charge and discharge cycles of the battery.

Let us look at an example: Let us say there is a lithium battery that uses only half of its charge in one day and is then charged fully.  On the next day, it again only uses half of its power.  Although the battery has been charged twice, this does not count as one charge cycle but two.

A charging cycle is when a battery goes from being fully charged to empty and then from empty to fully charged; this is not one single charge. Just based on the previous example, it’s clear that it can usually take several charges to complete a cycle.

Every time a charging cycle is completed, the battery capacity decreases a bit. However, the reduced capacity is very small. High-quality batteries will still retain 80% of their original capacity after many cycles of charging. Many lithium battery products will still be used after two or three years. Of course, after the end of the lithium battery life, it still needs to be replaced.

Ultimately, a 500-cycle life means that a manufacturer has achieved about 625 recharge times at a constant discharge depth (such as 80%) and reached 500 charging cycles.  In other words, if we ignore other factors that could reduce the Lithium-ion battery capacity and we take 80% of 625, we receive 500.

However, due to various factors in life, especially considering how the depth of discharge (DOD) during charging is not constant, “500 charging cycles” can only be used as a reference to battery life.

Overall, it is better to think of the life of the lithium battery as related to the number of times the charging cycle is completed and not as directly related to the number of charges.

Deep and shallow charging

Here is another way to think of the cycle lives of lithium-ion polymer batteries: the life of a Lithium battery is generally 300 to 500 charging cycles. Assume that the capacity provided by a full discharge is Q. If the capacity reduction after each charging cycle is not considered, lithium batteries can provide or supplement 300Q-500Q power in total during its life. From this we know that if you use 1/2 each time, you can charge 600-1000 times; if you use 1/3 each time, you can charge 900-1500 times. By analogy, if you charge randomly, the number of times is uncertain. In short, no matter how a Lithium battery is charged, it is constant to add a total of 300Q to 500Q of power. Therefore, we can also understand this: the life of a Lithium battery is related to the total charge of the battery and has nothing to do with the number of charges. The effects of deep charging and shallow charging on lithium battery life are similar.

In fact, shallow discharge and shallow charges are more beneficial to lithium batteries. It is only necessary to deep charge when the power module of the product is calibrated for lithium batteries. Therefore, lithium-ion-powered products do not have to be constrained by the process: they can be charged at any time without worrying about affecting the battery life.

Effects of temperature on battery life

If a Lithium-ion Polymer battery is used in an environment higher than the specified operating temperature (above 35℃), the battery’s power will continue to decrease.  In other words, the battery’s power supply time will not be as long as usual. If a device is charged at such temperatures, the damage to the battery will be greater. Even if the battery is stored in a hot temperature environment, it will inevitably cause damage to the battery. Therefore, it is a good idea to extend the life of lithium-ion polymer batteries by using it under normal operating temperatures as often as possible.

If you use Lithium batteries in a low-temperature environment (below 4℃), the battery life will also be reduced. Some older Lithium batteries of mobile phones cannot even be charged under low temperatures.  However, unlike in high temperatures, once the temperatures rise, the molecules in a battery will heat up and immediately return to the previous charge.

Having explored battery performance under these extreme temperatures, the question now becomes if there are any batteries that can be used in environments with low or high temperatures.

Currently, GREPOW’s batteries can be used at temperature ranges of -50 ℃ to 50 ℃ or 20 ℃ to 80 ℃. Our low-temperature Lithium batteries’ discharging current of 0.2C at -50℃ is over 60% efficiency, over 80% efficiency at -40℃, and around 80% efficiency at -30℃.

We can further custom-make batteries depending on your specifications.

The graphs source  by Grepow Low-temperature lithium battery

The graphs source  by Grepow Low-temperature lithium battery

Charge-discharge cycle

To get the most out of lithium-ion batteries, you need to use it often so that the electrons in the Lithium batteries are always in a flowing state. If you do not use lithium batteries often, please remember to complete a charging cycle every month and do a power calibration, i.e. deep discharge and deep charge, once.

After the nominal number of charge and discharge cycles is used up, a battery’s ability to store power will drop to a certain level, but the battery can continue to be used.

Lithium batteries have no limit on the number of times they can be recharged. Regular manufacturers can charge and discharge batteries at least 500 times, and the capacity is maintained at more than 80% of the initial capacity. If charged and discharged once a day, batteries can be used for two years. Usually, batteries in mobile phones are charged 1000 times or more, which causes the batteries to be severely non-durable.

Below is a proper method of maintaining your mobile device’s battery:

1. When you charge your phone, fully charge it each time.
2. Do not fully discharge the battery. The battery needs to be charged when the power is less than 10%.
3. Charge with the original charger; do not use a third-party charger.
4. Do not use your mobile phone while it is being charged.
5. Don’t overcharge: stop charging after the battery is full.

According to the experimental results, the life of a lithium battery continuously declines with an increase in the number of charges.

Lithium battery cycle specified by the national standard

In order to measure how long the rechargeable battery can be used, the definition of the number of cycles is specified. Actual users use a wide variety of tests because tests with different conditions are not comparable, and the comparison must define the definition of cycle life.

Lithium battery cycle life test conditions and requirements specified by the national standard are as follows:

Charge at 1C under the environment temperature of 20 ° C ± 5 ° C. When the battery terminal voltage reaches the charging limit voltage of 4.2V, change to constant voltage charging until the charging current is less than or equal to 1 / 20C, stop charging, leave it for 0.5h to 1h, and then discharge it at 1C to the termination voltage of 2.75V.

After the discharge is completed, leave it for 0.5h to 1h, and then perform the next charge and discharge cycle two consecutive times. Less than 36min, the end of life is considered, and the number of cycles must be greater than 300 times.

Having gone over the national standard, we should explain the following:

1. The standard specifies that the cycle life test is performed in a deep charge and deep release mode.
2. The cycle life of the lithium battery is specified. According to this model, the capacity is still more than 60% after ≥300 cycles.

However, the number of cycles obtained by different cycling systems is quite different. For example, the other conditions above are unchanged, and only the constant voltage of 4.2V is changed to a constant voltage of 4.1V for the cycle life of the same type of battery. In this way, the battery is no longer under a deep charge, and the cycle of life can be increased by nearly 60%. Then if the cut-off voltage is increased to 3.9V for testing, the number of cycles should be increased several times.

With regard to this statement that the charge and discharge cycle is one less life, we should pay attention to the definition of the charging cycle of a lithium battery: a charging cycle refers to the full charge of the lithium battery from empty to full, and then from empty to full the process of. And this is not the same as charging once.

In addition, when we talk about the number of cycles, we cannot ignore the conditions of the cycle. It is meaningless to talk about the number of cycles aside from the rules because the number of cycles is just a way to measure battery life.

If you want to learn more about batteries or our custom-made batteries, please contact us at info@grepow.com and visit our website: https://www.grepow.com/.

GREPOW’s Solution For Batteries of Bluetooth Headsets

New Era, New Technology

At the start of the 21st century, Bluetooth was considered to be a relatively new invention. The creation of this modern technology provided consumers with a glimpse into the world of wireless communication. The very first consumer Bluetooth product was a mobile headset that required no hands to operate. The product received phenomenal reviews among consumers, and, shortly after the immense success of the first product, the marketplace soon flooded with other Bluetooth inventions. The invention of Bluetooth soon proved to be a more economical and more efficient method of communication.

Creation of the Bluetooth Headset

Being the first Bluetooth product to hit the marketplace, the Bluetooth headset paved the way for immense technological advancements in its field. The modern invention of a hands-free headset allows consumers to communicate without the use of pesky wires and cables that can easily become tangled. Gone are the days of struggling to untangle wires and accidentally yanking the cable out of the device. Over a short distance, radio waves are capable of replacing cables or wires in connecting Bluetooth-enabled products, allowing customers to connect or ‘pair’ their two devices and use them to enjoy wireless communication.

In the modern era, Bluetooth headsets are increasingly favored over other wired headphones and earbuds. The most crucial proponent of popular technology is the lack of wires and cables. Moreover, its lightweight design and sleek, modern shape increase its likability among consumer demographics. Finally, the marketplace offers a variety of different brands and models of Bluetooth headsets, giving consumers a wide variety of options.

The Battery for Bluetooth Headsets

The majority of successful Bluetooth headsets are designed with versatility and durability in mind. The headsets strive to be lightweight, sleek, and as compact as possible. Although lightweight models of Bluetooth headsets are favored over bulky ones, a compact headset leaves little room for one crucial element: the battery.

The battery is the heart of any Bluetooth product. Without a battery to power the device, the combination of a lack of wires and cables leads to a useless piece of modern technology. This element of a Bluetooth headset leads to one decisive drawback of lightweight designs: a minuscule Bluetooth headset battery capacity.

The smaller the headset, the less space there is to place a battery. Does that mean you must sacrifice a contemporary and compact design for a bulkier one with increased battery life? Not necessarily.

A typical battery either has a rectangular or circular shape, depending on the specific size of a device. Smaller devices, such as a Bluetooth headset, would require circular batteries to operate. Larger headsets would require the power of larger rectangular batteries. Due to the popularity of small Bluetooth headsets, most models use small circular batteries that have a capacity range from 80 mAh to 150 mAh. Moreover, the compact size and unique design of the headsets cause a size restriction that leads to an inability to house larger batteries; this leads to Bluetooth headsets with short battery life.

Custom sizes and shapes

GREPOW is a company based in Shenzhen, China that is rapidly remedying the issue of standard-sized and shaped batteries. After immense research and development, GREPOW has created batteries of a variety of sizes and shapes that can fit into the unique designs of modern Bluetooth technology. The lightweight and compact designs of Bluetooth headsets are no longer a barrier in regards to the size and shape of the required batteries.

GREPOW is a company that understands that as the world continues to modernize, technology must change right alongside it. That is why GREPOW is the proud manufacturer of different Bluetooth headset battery shapes. With GREPOW’s research and technological advancements, Bluetooth headsets are now able to use the space of their devices more efficiently, utilizing unique battery shapes to give consumers an extended battery life.

Modern Issues Require Modern Solutions

GREPOW offers consumers some different options for battery shapes of Bluetooth headsets:

• Ultra-thin batteries
• Ultra-narrow batteries
• Curved batteries
• Round batteries
• Square batteries
• Rectangular batteries
• Polygonal batteries

With the diverse selection of battery shapes, gone are the days of Bluetooth headsets with short battery life. Unique headset shapes now have unique battery shapes to accompany them in utilizing space efficiently and giving consumers devices with extended battery life. If your headset has a one-of-a-kind shape, GREPOW is capable of customizing a battery shape that fits your headset. Moreover, customers are also able to customize the smallest details within a battery including capacity and voltage. With the modern technological abilities of GREPOW, wasting space inside of a headset is no longer a viable option.

GREPOW Batteries

The batteries that GREPOW manufactures not only have unique shapes, but they also have high output power and capacity while continuing to be compact, durable, and lightweight.

For example, GREPOW battery model GRP6530027 has a capacity of 430 mAh while still maintaining a compact and round shape. Furthermore, this battery has a 3C discharge rate, 4.35V high voltage, and a very lightweight of 7.7gram.

GREPOW batteries can also be customized with different performances, such as low-temperature use, ranging from -50℃ ~ 50℃, or high-temperature use of 20℃ ~ 80 ℃. They can also be packed in series and/or parallel combinations and be able to integrate power solutions upon customer’s requests.  Many testing requirements, including ROHS, SGS, CE, UL, IEC, CB, UN, etc., are met as well.

If you purchase a GREPOW battery, you are guaranteed a lightweight and compact battery with high energy density and long battery life. Along with that, each customer has the guarantee of quality assurance, high consistency, and after-sales services.

Make the switch to a GREPOW battery to experience modern technology at its finest.

More information can be found here: Novel Battery

Contact GREPOW at info@grepow.com .

Stretchable and Flexible Battery

Hi all,

I would talk to you about a sketchable and flexible battery developed by some universities.  It’s the first sketchable battery but not the first flexible.

The first one is a battery created by  a research team in South Korea (the picture below)

The researchers at Northwestern University and the University of Illinois created the first sketchable battery with many cells of Li-ion wiring by zigzag wire.

The use of this battery could power the wearable devices. The skinnable battery can be wearable like a patch. It’s already existed for transdermal drug delivery with a flexible battery.

I find a video where we can see the sketchable capacity of the battery:

http://bit.ly/2IYDbtG

Different Packaging Methods for Lithium Batteries

There are two main packaging methods in the production of Lithium batteries: Rolling and Stacking.  We will explore both methods in this article.

1. Rolling/Winding

Rolled cells are also known as winding cells or jelly rolls. Rolling was the first method introduced in producing Lithium batteries. This method has been used for a long time in the production of NiMH (Nickel-Metal Hydride) and LiPo (Lithium-ion Polymer) batteries.  In this method, long layers of material are stacked and rolled.

This method allows for a  high level of efficiency and consistency in the turnout of the product.

Some disadvantages include a low space utilization caused by the fixed cylindrical shape and temperature distribution caused by poor radial thermal conductivity.  The number of cycles also cannot be too large; generally, one 1650 battery will have 20 cycles.  Due to this, the capacity is small, and a large number of cells must be packed into the battery modules for electric vehicles.

Although the Cylindrical Rolling method appears simple, the internal design is anything but.  Its complex design requires symmetry between the contact between the positive and negative electrodes, heat distribution, and the production machinery.

Let us explore two examples of batteries that are produced with this method:

The image above includes the internal dimensions in mm of a 18650 battery.  The length of the electrodes between the cathode and anode nearly comes out to 1.5 meters when laid out while the width of the tabs comes out to only 4mm.

In order to reduce the uneven current and temperature distribution, engineers must carefully consider how they will arrange the tabs and electrode coatings.

(Reference: Waldmann et al., JES 161 (10) A1742, 2014)

The image above reflects warping, which occurs due to the inconsistent volume changes of the electrode layers.  This is one of the reasons that cause the aging failure of batteries produced under a winding method.

The images below show the magnified electrode shapes of 18650 batteries under CT after storage, low-rate cycling, and high-rate cycling.  Warping can be seen in the first image, labeled a).  The second image, labeled b), shows how a pin is added in the middle to suppress the deformation of the core.

(Reference: Waldmann et al., JES 161 (10) A1742, 2014)

Although beneficial, the pins increase the weight of the battery and production costs.

2. Rectangular Stacking (Pouch Cells)

Pouch cells are created by stacking multiple electrode sheets on top of each other in what is known as the Stacking method.

There are many advantages to these pouch-shaped cells:

1. Due to the contact of the anode and cathode and its ratios allow for better heat dissipation.
2. The shape allows for higher efficiency and utilization in space, and they make modules and battery packs easy to form. Our batteries are more customizable, and we have ultra-thin batteries that can be around 0.4mm in thickness.
3. The distribution of current density is uniform as each electrode layer has a flange and tabs welded together. 

There is one disadvantage to this method:

1. The pouch layer is so thin that the pouch itself is semi-conductive.  This thus results in positive pouch corrosion when utilized inside devices.  A simple solution to this is to wrap the cell in Kapton tape.

(NASA, Li-ion Pouch Cell Designs: Performance and Issues for Crewed Vehicle Applications)

In summary, in order to compare the advantages and disadvantages of various types, we need to analyze from many angles such as thermal, mechanical, and reliability, not just the traditional electrochemical characteristics. That’s the packaging methods in the production of lithium batteries.

If you are interested in lithium battery, please don’t hesitate to contact us at any time!
Grepow Website: https://www.grepow.com/

Why does a Phone Battery Drain Faster in the Winter？

Temperatures around the US vary, but there are many areas where it is still cold and snowing.  You may have noticed that when you use your mobile device outdoors on a cold day, the battery power may have dropped quickly; in some cases, the phone may have even turned off.

In this article, we will address whether the lithium battery in mobile devices consumes more power in lower temperatures, and we will explore low-temperature battery options.

An Experiment: A battery indoors

In order to come to an answer, let us explore an experiment where there are three mobile devices from different brands.  These phones would be charged to 100% then unplugged and left with their screens on for two hours straight.  All three phones would run the same programs to ensure similar power consumption, and the indoor temperature would remain at 21°C/69.8°F.  After 20 minutes, we will most likely find the batteries of all the phones still at 100%.

An Experiment: A battery  outdoors

Now, in a separate experiment, we would have three phones from different brands, and, similar to the previous experiment, these devices would be charged to 100% then unplugged and left on for two hours while running the same apps.  However, this time, the phones would be taken outdoors near the snow where the temperature would be 3°C/37.4°F.  After 20 minutes, we will likely see a different number representing the batteries’ status.

Just performing these two experiments would tell you that the batteries of mobile devices consume power at different speeds depending on the surrounding temperatures.  After 20 minutes, the second experiment will show the batteries at around 97 or 95%.

Ordinary batteries at low temperatures

Most mobile devices for the general public use a Lithium-ion Polymer battery (LiPo battery).  When the temperatures drop low in the winter, the chemical reactions of the electrolytes slow down and result in less current and a decrease in battery power.

In more extreme situations, the phone will automatically shut down.  The decrease in power or auto shut down are both protective measures.  The shut down itself differs by manufacturer: some phones will shut down at 0% while others will automatically shut down the temperatures drop too low.

Tips to use your phone in cold temperatures

When we are outdoors, there are some simple actions that you can take to prolong the use of a battery without having to charge it.

First, try not to expose your phone to low temperatures.  Keep it in your pocket or in your bag where it can be enclosed away from the cold.

If a phone call comes in, use your earphones to answer it instead of bringing your phone out.

If your phone is turned off outside, wait until you warm up before restarting it when you’re back indoors.  You want the battery to acclimatize to the temperatures indoors.

More simply, place a protective shell around the phone.

You can also choose to use a professional low-temperature battery that can be used normally even in low temperatures.

Grepow can actually help you with that.  We have low-temperature LiPo batteries that can operate in a temperature range of -50°C/-58°F to 50°C/122°F.   They can discharge at over 60% efficiency with 0.2C and -30°C/-22°F.  When charged at 20°C/68°F to 30°C/86°F by 0.2C, the capacity can be maintained above 85% after 300 cycles. These batteries can be ready for mass production, and they have been widely used in cold climates and military products.

These low-temperature batteries are specially developed by Grepow in order to overcome the defects inherent in batteries when they are exposed to lower temperatures.  Our low-temperature batteries are manufactured with an innovative concept design, advanced formulas, and rigorous manufacturing process and method.

Keep an eye out for Grepow’s official blog, where we regularly update industry-related articles to keep you up-to-date on the battery industry.

Grepow website: https://www.grepow.com/

Grepow Blog: https://blog.grepow.com/