8 Inspiration for Flexible Batteries

 

People’s needs and other electronic products such as wearable electronic devices, electronic paper, smart clothing, etc. have urgently needed foldable and retractable flexible batteries. Lithium-ion batteries have become an ideal research object for flexible batteries because of their higher energy density and longer service life. A complete lithium-ion battery contains the main parts of the positive electrode, negative electrode, separator, electrolyte, current collector, and battery packaging materials. During the folding and stretching process of the flexible battery, each part has to undergo certain deformation. Therefore, the materials and structures of all parts of the flexible battery must maintain performance after several times of folding and stretching.

Table of Contents

• Applications of Bionics
  • 1. Buckling structure
  • 2. Origami
  • 3. Paper cut
  • 4. Spring
  • 5. Porous structure
  • 6.2D “Crack”
  • 7. Mesh structure
  • 8. Self-repair function

Applications of Bionics

After hundreds of millions of years, the creatures on earth have been constantly evolving to adapt to the changing living environment. We humans also draw inspiration from the changes in nature and create many new things. “Bionics” has been used in various fields. For example, radial and spiral filaments make spider webs have good toughness and elasticity. People have made nanofiber webs based on spider webs. For another example, according to a paper-cut craft in our daily life, flexible supercapacitors with similar structures also get good performance. During the development of flexible batteries, what inspirations have we got from nature? This article will introduce in detail.

Applications of Bionics

1. Buckling structure

The buckling structure, also known as the wave-shaped structure, is a wave-shaped stretchable structure as the name implies. The active material is usually coated on a wave-shaped metal pole piece to make a stretchable electrode. The multi-layer buckling structure based on this wave structure shows better performance. In 2015, Fang and Baughman’s research team jointly published an article on Science. The carbon nanotube layer (NTS) is rolled onto a stretched elastic rubber fiber. When the fiber tension pressure is released, its surface is covered. The carbon nanotubes formed a multilayer buckling structure. This kind of multi-buckling structure carbon nanotubes has a resistance change of less than 5% when the tensile deformation is 1320%, which has good application potential in flexible batteries.

Figure 1. The formation process and SEM picture of multilayer buckling structure

2. Origami

Origami is the art of folding or folding paper. The paper is folded into a specific shape and pattern. Intricate designs can be created only through the skill of folding. By folding, bending, etc., the 2D dimensional paper is folded into various shapes in 3D space. And what kind of spark did the application of origami technology to flat lithium-ion batteries sparked? In 2014, the Jiang research team of Arizona State University assembled the current collector, positive electrode, negative electrode, separator, and packaging material according to two different angles. When stretched or bent, the battery can withstand great stress due to the folding effect. Very good elasticity, and still maintain a good cycle capacity after folding the battery many times.

Figure 2. Assembly diagram of the folded battery

3. Paper cut

Paper-cutting is one of the oldest folk art in China. It is used to cut patterns on paper to decorate life or cooperate with some folk activities. Unlike origami, paper cutting involves cutting paper. In 2015, the Song research team of Arizona State University produced a “cut-N-shear” battery assembly structure through cutting and folding. When there is an external force, the notch can be rotated to adjust the structure. The battery assembled by this method can still maintain energy storage performance when stretched by 150%.

Figure 3. “cut-N-shear” battery assembly structure diagram

4. Spring

Springs can be seen everywhere in our lives. The spring is widely used because of its good elasticity and restoring force. In the design of flexible batteries, the source of inspiration is also indispensable. The Peng research team of Fudan University winds carbon nanotubes on spring-shaped fibers, and the resulting carbon nanotube electrodes retain their shape and capacity during the stretching process. They also made Li4TiO (LTO) anode material and LiMn2O4 (LMO) cathode material together into a spring structure. The battery capacity of this structure does not change when stretched.

Figure 4. Schematic diagram and SEM photo of battery assembly with spring structure

5. Porous structure

Porous structures, such as sponges, not only have good water absorption but also have good elasticity. In 2016, Yi Cui of Stanford University filled the electrode material, carbon material, and binder into the sponge-like PDMS to form a 3D porous lithium-ion battery that maintained excellent energy storage performance when stretched by 80%.

Figure 5. Schematic diagram of sponge battery

6.2D “Crack”

Sometimes the formation of cracks is not necessarily a bad thing, distance can produce beauty. When thermal electron beam evaporation or electron beam evaporation produces gold thin films, micro-cracks can be formed on the thin films by controlling parameters. When there is an external force, these cracks can act as a buffer. Conductive polymers such as PEDOT: PSS, P3HT, etc. will also use this strategy in the production process to increase the flexibility of the polymer film.

Figure 6. SEM pictures of the gold film (with microcracks) on PDMS substrate before and after stretching

7. Mesh structure

The web-like structures in nature such as spider webs have excellent mechanical properties, are very soft and tough, and some web-like structures, such as leaf veins and rivers, can be effectively transported by cross-linked webs. All these structures are used to make flexible electrodes. The simplest method of making mesh electrodes is to randomly coat the active material on the surface of the elastic substrate or inject it into the inside. When pressure is applied from the outside, the active material will be compressed and connected together. This method will not destroy the original structure of the active material, and at the same time can produce good conductivity. The silver nanowires produced by the Lee and Ko research groups of the Korean Academy of Science and Technology form a net-like circuit network when stretched, and have good conductivity when used as electrodes.

Figure 7. Reticulated silver nanowire electrode

8. Self-repair function

Although many different methods are envisaged to make flexible materials, the actual situation is often more complicated. When a flexible instrument containing both flexible and rigid materials receives an external force, the internal structure of the instrument will inevitably undergo structural changes and even damage. Inspired by the self-healing mechanism of natural organisms and plants, flexible batteries have a similar design. In 2012, Zhenan Bao’s research team at Stanford University filled nickel nanoparticles into self-healing polymers at temperatures below room temperature. At 31% nickel content, the composite can be used as an electrode, and at 15% nickel content, the composite can be used as a mechanical sensor. When the two ends of the composite are placed at room temperature, it can self-repair external force damage and restore electrical conductivity.

Figure 8. Nickel composite electrode structure with self-healing function

Functionalization has always been the ultimate goal of people developing new materials. And just like us humans, many complex behaviors do not rely on a single organ and require coordination of various parts. The same is true for flexible batteries, which require all parts of the battery to cope with changes in external forces. Nature provides us with space and food for our survival. It also gave us a lot of inspiration. The development of flexible batteries draws on many examples from nature. At the same time, we believe that more scientific researchers will apply “bionics” to flexible batteries to promote the development of flexible batteries.

What is a Flexible Battery?

 

Flexible batteries refer to batteries that can be folded and twisted at will, including primary and secondary batteries. Unlike traditional rigid batteries, their design is conformal and flexible. They can maintain their characteristic shape even when continuously bent or twisted. It is to turn the traditional liquid electrolyte into a solid-state, and “print” the internal structure of the traditional lithium-ion battery on the flexible substrate so that the battery will not be “powered off” even if it is bent or folded, thereby ensuring the battery It can work normally even after bending or folding.

Demand for flexible batteries

We are used to thinking of batteries as bulky tools that can store energy and power electronic devices. For a long time, disposable carbon-zinc batteries, rechargeable lead-acid batteries, and nickel-cadmium batteries have been dominant.

Figure 1: Market descriptions by territory      Source: IDTechEx

With the emergence of portable devices such as netbooks, ultrabooks, and other handheld devices, the battery market has seen explosive growth of various types, among which the most popular is lithium-ion rechargeable batteries. However, as electronic products become thinner and more flexible, batteries must now get rid of their rigid form and adapt to their bending. Therefore, the thin-film flexible battery market has also followed.

Market observer IDTechEx predicts in their new report that by 2026, the current small thin-film battery market will reach US$470 million. According to He Xiaoxi, a technical analyst at IDTechEx, this is the reason why companies such as TDK, STMicroelectronics, LG, Samsung, and Apple are increasingly involved. Considering the Internet of Things, the deployment of wearable devices and other environmental sensors is getting faster and faster, and it is imperative to replace traditional battery technology. New dimensions and designs are urgently needed. For example, Samsung has a curved battery in the Gear Fit wristband.

Flexible battery manufacturers

The GREPOW battery manufacturer has more than 20 years of battery manufacturing experience. Special-shaped battery technology is mature. The advantages of the special-shaped battery are their adaptability, lightweight and portability, which makes them easy to be used in products such as small and wearable electronic devices. achieve. Therefore, GREPOW is working hard to manufacture different shaped batteries, including rechargeable batteries with high energy density and good shape, and is in a leading position in the industry. Here are two types of batteries related to flexible batteries: curved batteries, Thickness: 1.6 mm ~ 4.5 mm; Width: 6.0 mm ~ 50 mm; Inner arc length: 20 mm ~ 55 mm; Inner arc radius: ≥8.5 mm.

Figure 2: curved battery      Source: GREPOW battery

Another GREPOW special-shaped battery: ultra-thin battery, Charge the battery to 3.83v and fix the battery to the surface of the white PVC card. Fix the cell pole card to the bending and torsion tester, 15 degrees forward and backward, and 30 degrees total distortion, for bending and torsion test. After the bending and torsion test of the 0.45mm ultra-thin cell for 9000 times, the surface of the cell was folded and the internal pole sheet had creases. The internal resistance increased by about 45%. The voltage before and after the bending and torsion basically remained unchanged.

Figure 3: ultra-thin battery      Source: GREPOW battery

STMicroelectronics (ST) is producing thin-film solid-state lithium batteries in small quantities. The report said that two other companies are producing printed batteries. Therefore, there are now various flexible batteries on the market competing for power to power several devices.

Other companies are also trying other strategies. For example, TDK is developing battery-less energy harvesters. The idea is because IoT nodes and wearable devices require extremely low power to operate, so they can be operated by energy harvesters instead of batteries. Other companies such as Oakridge Global Energy Solutions Inc. plan to increase production capacity at their Brevard County, Florida plant. They will manufacture electrodes and batteries for thin-film solid-state lithium batteries. They acquired this technology from Oak Ridge Micro-Energy Inc. in 2002 and plan to start mass production in early 2017.

Types and applications of flexible batteries

Various flexible batteries will soon be on the market. These will include thin-film batteries, printed batteries, layered lithium polymer batteries, micro-batteries, advanced lithium-ion batteries, thin flexible supercapacitors, and stretchable batteries.

Understandably, they will have multiple uses. For example, wearable devices are expected to become the greatest potential for flexible batteries. Printed batteries in the form of skin patches have been used in the healthcare industry, and the market is growing steadily. At present, although the high cost of printed zinc batteries hinders its widespread application, this application has the greatest potential. According to the IDTechEx report, the market for micro-power batteries that power disposable medical devices will expand rapidly.

Figure 4: Applications of batteries with new form and structural factors     Source: IDTechEx

There are other requirements for batteries that power various types of power sources, displays, and flexible sensors. The U.S. Department of Defense has invested $75 million to create the Flexible Hybrid Electronics Manufacturing Institute in San Jose.

The promotion of flexible batteries and flexible electronics is of great significance. Based on the demand for electronic equipment for batteries, the promotion of flexible battery technology and the cooperation of flexible display, biosensor, and flexible circuit technologies will help to develop more flexible electronic devices for medical health monitoring, smart textiles, smartphones, and global It is applied in multiple scenarios such as positioning system tracking, Internet of Things, and human-computer interaction.

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

What is a Good-quality Rechargeable Button-cell Battery?

  

Rechargeable button-cell batteries are widely used in various devices, so it’s important to know the characteristics of these batteries.  We will briefly explore some of these attributes in this article.

Safety

Safety is one of the most basic and important manufacturing guidelines for all batteries. To prevent short circuits and leakage in button-cell batteries, manufacturers of rechargeable button- cell batteries choose chemically stable materials.

Stability

The M-shaped bump process allows for better contact with machines, which allows for more durability and elimination of frequent replacements. The performance will not be affected even in bad weather conditions. Disassembly and assembly are also easier and faster, and spare batteries can be replaced at any time. Rechargeable button cell batteries allow the appliance to run steadily for a long time, reducing various potential hazards and ensuring personal safety.

Good conductivity

The applications of rechargeable button-cell batteries usually require the coexistence of corrosive chemicals or airborne contaminants in a dry environment. Therefore, they must have good electrical conductivity. Only when their electrochemical properties are excellent will the batteries be able to perform their task.

Long life

The long life expectancy of rechargeable button-cell battery products is one of the button cell’s many advantages. Under normal conditions of use, the charge and discharge cycle can be recycled ≥400 weeks, and the capacity ≥80%. 

High-cost performance and very good conductivity

Rechargeable button-cell batteries are highly cost-effective and highly conductive. Adding some beneficial metals not only ensures power performance but also improves their cost-effectiveness, so many battery manufacturers will use this method to produce rechargeable button-cell batteries.

In general, rechargeable button-cell batteries have a significant role in preventing accidental short circuits and leaks. Chemically stable materials usually have a higher safety factor. Batteries are also more durable, and they won’t hinder performance in harsh climates. They will not leak, explode, or spontaneously combust.

All in all, the advantages of rechargeable button-cell batteries are obvious. Since rechargeable button-cell batteries are not soldered to a printed circuit board, there is no need to surround it with other components and housings as their removal is usually very simple and easy.

Contact us for customization needs at info@grepow.com

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

Extend the Life of Standard Lithium-ion Battery

 

In today’s mobile world, standard lithium-ion batteries are used in a myriad of situations, and battery life comes to be precious. It can be especially annoying when a mobile device has to be charged in a public place with only one available outlet.

There are many reports on how to save battery power, but what can we do to extend battery life? Here are a few ways that Grepow has you covered.

Keep the battery at room temperature

Store the battery between 20 to 25℃. During the charging process, the temperature of the battery will increase due to the electric current. Therefore, do not leave your battery in the car or charge it if the temperature inside the car is too high. Heat is the biggest factor in shortening the life of a lithium battery.

Consider purchasing a high-capacity rectangle lithium battery

Standard rectangular rechargeable batteries will degrade over time regardless of whether they are used or not. As a result, spare batteries will not last longer than batteries in use. When purchasing a battery, be sure to ask about the latest manufacturing date of the product.

Avoid completely discharging the lithium battery

If the discharge voltage of each cell of a standard lithium-ion battery falls below 2.5V, the safety circuit built into the battery will break, and the battery will appear to be depleted. For safety reasons, do not charge an over-discharged lithium-ion battery if it has been stored under these conditions.

If you are storing the lithium batteries for an extended period of time, store them at a storage charge in a cool place. Only by storing the battery properly can excessive power consumption be minimized and the life of the battery extended.

Stay tuned for more battery technology or visit Grepow’s Website now: https://www.grepow.com/

What are the advantages of the soft pack rectangle battery?

 

The main advantages of rectangular pouch batteries are their thin profile and efficient use of space. The slim rectangular shape adds to better layering and increased flexibility, and they are commonly found in a variety of small electronic devices.

Table of Contents

8 Advantages of choosing rectangular batteries

Li-ion battery pack flexibility

This is a fully assembled battery pack with a built-in BMS as the standard battery module. The modules are assembled in a parallel configuration to increase capacity and in a series, configuration to increase voltage. The built-in BMS can provide an output cable for communication.

Long cycle life

We randomly selected a rectangular pouch cell from our production line. After constant cycling and equivalent acceleration of more than 4400 charging cycles, the 10Ah battery still recorded about 9Ah. After repeated charging, the battery capacity was only reduced by about 10%.

Reliability

When one rectangular pouch battery fails, the other rectangular pouch battery can simply take over. When you replace a single faulty rectangular pouch battery, the rest of the system can continue to operate normally, thus improving system reliability.

Improved energy storage

Compared to a cylindrical battery, a soft-packed rectangular battery has a much larger capacity to store energy in a given physical space.

Safety

When a cylindrical cell has internal problems, the pressure increases and expands. In those uncommon instances, a soft-packed rectangular battery will only expand.

On the other hand, cylindrical batteries are housed in a steel sleeve. When pressure builds up in a cylindrical battery, the end of the cylindrical battery will be secured by another battery or case and may explode, thus posing a safety hazard.

Weight

Generally, the weight of a soft-pack rectangular battery is less than the weight of an equivalent cylindrical battery. Flat soft-pack rectangular cells have a greater energy density than other battery shapes, but they are also much more difficult to manufacture. For this reason, soft-pack rectangular batteries are one of the best products to test a battery manufacturer‘s production capabilities and techniques.

Consistency Rectangular Pouch Batteries

GREPOW‘s entire line of pouch rectangular cells are manufactured on automated equipment using stacking technology. The cells are manually tested to ensure that each cell is up to par, eliminating human error in manual cells and making each cell uniform.

The growing trend of rectangular pouch batteries

As the economy grows, the utilization of soft-packed rectangular batteries continues to rise. Low internal resistance and long battery life reduce the additional cost of battery replacements for customers, which makes these batteries ideal for wearables, smartphones, speakers, and other 3C products.

There is also a growing interest in the safety and energy-density benefits of pouch batteries. The penetration rate of soft-pack batteries in more areas will gradually come to increase.

If you are interested in our products, please don’t hesitate to contact us:

Email: info@grepow.com

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Novel Batteries are Needed in this 5G Era

 

I believe that many people have encountered the embarrassing situation of insufficient mobile phone battery power and unable to find a place to recharge when they were out for fun or shopping.

With the advent of the 5G communication era, a new generation of consumer electronic products is developing rapidly. Behind the innovation of high-speed, large-capacity, and low-latency communication technology, the demand for equipment carrying power will also increase.

So, in the face of the current rising demand for power-carrying equipment, what new research developments are there in lithium battery technology suitable for consumer electronic devices? Where will the future direction of battery technology innovation go?

Next, GREPOW Battery will share with you the challenges and subversions of consumer electronic battery technology brought about by the arrival of the 5G communication era.

the IoT is inseparable from strong “power” in the 5G era

Tablet computers, Bluetooth speakers, smartphones, consumer robots… the types of consumer electronic products continue to increase. On the one hand, the emergence of these consumer products brings people a real and convenient experience; on the other hand, people will often The actual users who have seen such products complain that the products are unsatisfactory in one way or another.

The advent of the 5G era is not just about changing network speeds as simple as a series of power support systems. If the Internet connects people and things more closely, then the arrival of the 5G era will not only increase the speed of this connection but also enable basic coordination between things.

The mobile phone is out of power and meets an emergency. At this time, we especially hope to have a mobile phone battery with a lot of power. At present, most of the batteries used in mobile electronic products such as mobile phones and tablet computers on the market are mostly lithium-ion batteries. Although designers have been using various methods to increase the capacity of the batteries, they are in line with the rapid innovation of consumer electronics. Compared, it still makes people feel more exhausted.

The 5G era of the Internet of Everything will undoubtedly drive the demand for hardware performance of various mobile devices, including mobile phones, wearable electronic products, Internet of Things devices, drones, and so on. In this context, whether the battery’s endurance can support the high-speed computing demand brought by 5G will be an important issue worthy of attention.

Industrial innovation requires novel batteries

Currently, the more mature battery in the 3c market is lithium cobalt oxide, which is also the most widely used cathode material in the consumer electronics market. At present, the mainstream commercial lithium battery cathode materials on the market mainly include lithium cobalt oxide, lithium manganate, lithium iron phosphate, ternary materials (lithium nickel cobalt manganate, lithium nickel cobalt aluminate), etc. The latter three main requirements In power batteries, lithium cobalt oxide is more used in consumer electronics.

For consumer electronic batteries, the input and output performance of lithium-ion batteries mainly depends on the structure and performance of the internal materials of the battery, including negative electrode materials, electrolytes, separators, and positive electrode materials. The lithium cobalt oxide battery has the advantages of high specific gravity, high volume, and high energy density, so it has become the best choice for consumer electronic products.

However, with the advent of the 5G era, consumer electronics products continue to introduce new ones, and people’s demand for battery capacity is also rising linearly, requiring battery products with greater flexibility, longer running time, lower cost, and higher Security. The characteristics of consumer electronic devices have also put forward more stringent requirements on the new generation of battery technology. The contradiction between the continuous miniaturization of the volume and the battery capacity, the contradiction between the charging and discharging speed and the number of charging and discharging, etc. are all urgently needed to be resolved. The problem.

For companies, in addition to working hard on the stability and service life of batteries under the current technical framework, they also need to have a forward-looking sense of technological revolution and continue to increase the exploration and research of new materials and novel battery technologies. Be invincible when 5G comes.

In addition, as the new consumer electronics industry represented by wearable devices continues to increase, the demand for consumer lithium batteries is also increasing. Wearable devices usually use solid-state lithium battery ultra-thin battery technology. The technology and craftsmanship are basically mature, such as wearable devices such as bank cards, VR, and bracelets. According to the forecast of iiMedia Consulting, the demand for lithium batteries in the VR industry alone is expected to exceed 55 billion yuan by 2020.

Revolutionary battery technology

When it comes to the future of consumer lithium batteries, there will be two major development trends: one is technological innovation, such as increasing research on the replacement of positive and negative materials, to meet the dual requirements of consumer users for battery volume and capacity; the second is safety Performance requires a more cautious attitude when new high-capacity, high-density battery technologies move from the laboratory to the commercial market.

At present, in order to meet the user’s demand for battery life indicators on the market, the current consumer electronics merchants themselves are also trying to improve the battery experience from many aspects, such as fast charging technology. GREPOW batteries have excellent performance in this area and can be achieved 3C and 5C fast charge.

Fast charging technology uses a high-voltage current. By increasing the charging voltage, the charging rate of the device is finally increased, thereby shortening the charging time of the device, and thus the charging speed has been significantly improved.

In addition to fast charging technology, GREPOW’s new novel shaped batteries can be customized according to your device. The special shape can make full use of the space of the device, thereby increasing the battery capacity.

With the advent of the 5G era, high-definition audio-visual calls and high-power IoT applications will inevitably add unimaginable pressure to consumer electronics such as mobile phones. On the eve of the urgent need for systematic changes in battery technology, in addition to the fast-charging technology and special-shaped novel batteries just mentioned, it is also necessary to try new models to solve the problem of device battery life.

If you are interested in our products, please don’t hesitate to contact us at any time!
Email: info@grepow.com
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