Lithium Battery Cell Models and the Industry Shifts vs

By Anton Beck, Battery Product Manager
Epec Engineered Technologies

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The lithium battery industry has undergone great strides to meet the ever-increasing power demands of electronics and equipment. These batteries are found in power tools, cars, medical devices, and a range of other machines. Many different sizes and shapes of lithium batteries were being produced during the past two decades as demand fluctuated.

Cylindrical cell models come in a number of sizes as their popularity has caused massive growth in production. Several cell models are available, however, the two that are competing head-to-head when it comes to size and capacity are the vs. models (Figure 1).

Figure 1: Example of lithium battery cell models vs .

Battery Cell Basics

The battery cell model became the most optimized lithium battery to be produced in , although it has been around since as Panasonic first debuted this cell. The battery was longer and wider than the standard AA batteries as the numbers designate the cell model’s size. For the , it was 18mm diameter and a length of 65mm. These batteries provide 2,300 mAh to 3,600 mAh capacities and about 3.6 volts to 3.7 volts.

The cells neared a peak reaching , yet then came into new demand with the rollout of electric cars such as the Tesla. The production of drones, medical devices, and mil-aero equipment also required these batteries. In , nearly 2.55 billion cells were produced. The batteries had a good reliability rate and were low in costs to produce per watt hour.

When looking at the current market, many electronics have gone through drastic design changes. Equipment that required greater levels of power was becoming slimmer and flatter, such as tablets and smartphones. While the demand waned in these market sectors, the fear of battery shortages for the electric vehicle, mil-aero, and medical industries caused manufacturers to create an oversupply of these types of cells. However, the increasing power demands of electronics will soon cause a need for cells with greater capacity. Due to this scenario, the cell models may meet this rising demand.

Battery Cell Basics

The cells became introduced in . They were made in a joint effort between Panasonic and Tesla. The battery cell has a dimension of 21mm diameter and 70mm in length. The cells are slightly larger than the and have a higher capacity. These cells have the same nominal capacity of the batteries they were designed to replace, as they still came as 3.6 volts to 3.7 volts. Yet, they have a greater capacity of 4,000 mAh to 5,000 mAh.

The batteries may come protected or unprotected. Protected cells have a battery management system (BMS) for protection and to prevent overheating. Unprotected cells do not have these safety protections. While being available as cylindrical, the batteries may also come as flat and may also have a button-top version. These battery cells were designed to replace the for electric vehicles.

vs. Cell Comparison

When comparing cells to cells (Figure 2), the batteries have a 50% capacity. The cells also have a greater energy density and a discharge rate of 3.75c. Energy density increases are also lower for the as they may range from 2% to 6% depending on the manufacturer's internal construction for the cells.

The charge and discharge rates for both cells are basically similar. There may be higher polarization for the cells, while the cells have lower resistance and stronger heating. When the battery undergoes cycling, the capacity fades for cells and cells are the same.

Figure 2: Dimensional characteristics of the and cell models.

Industry Expectations

Electronics and car manufacturers have looked at the as a suitable replacement for previous lithium cell versions based on their ease of manufacturing as well as the higher capacity options. The design options for these cells are numerous, as they can come as button cells, prismatic cells, and pouch cells. For designs that have higher costs to the manufacturer, such as pouch cells, cost reductions can be obtained with both the cells as well as the cells. In addition, major cost reductions are expected for several years when manufacturing pouch cells as more economical production methods are introduced with the increase and changes in technology.

The benefits of having a battery cell with greater runtime and more capacity will allow the to be a suitable alternative to the . Yet manufacturers will still continue to roll out the cells for various applications that do not require the larger capacity to function and when space requirements force the cell design to be smaller in size than the .

When looking at the manufacturing industry for lithium cells, the need for lightweight batteries with flexible designs and high capacities will remain in demand for the foreseeable future. This increased capacity will force manufacturers to consider how to make changes to the cell models to convert them to without any redesign.

Higher Capabilities

The flexible PCB areas in rigid-flex circuit boards offer a higher range of capabilities than traditional rigid circuit boards with wired interconnects. When the product design requires high-speed signals and controlled impedance (Figure 4), the flexible board can handle the transmission loads effortlessly. The flexible areas can also provide high levels of shielding for EMI and RF interference from either component within the product or from outside sources. Another benefit to rigid-flex circuits is that they work reliably even when being used for applications in harsh environments. The boards have good corrosion resistance, chemical resistance, and UV resistance. They can also handle higher temperatures up to 200°C while being able to dissipate generated heat.

Summary

Many top-tier cell manufacturers are shifting their focus from the historically predominant cell model to the cell model. As more manufacturers move in this direction, the cell designs and chemistries will vary between each company. Selecting the right cell will be dependent on the requirements of the application, the size of the required battery, and other specifications. One of the major design considerations that will become an important factor with battery manufacturing rests with the flat cells. If the same cell performance of a cylindrical cell can be met when forming it into a flat cell design, the market for these cells will rocket forward for decades to come.

In the near future, the demand for cells will continue onward for many mil-aero, medical, and automotive applications. As more cell designs saturate the market, this saturation may cause manufacturers to lower the amount of available batteries when switching over their production line capabilities. Speaking with a battery pack manufacturer like Epec, regarding the design of their cells allows a company to figure out which type of batteries to use currently and what changes may need to be made in the future if a battery cell becomes obsolete.

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The year of has seen a lightning-fast development of cells. At the investors meeting earlier this year, Tesla announced a new battery, developed together with Panasonic, is going to start a mass production.

Later during the North American International Auto Show, Samsung SDI also announced the news of introducing the new battery of . Samsung SDI said the power density of the new battery is twice capacity with its counterpart of the same volume and the new battery can charge up to 370 miles (600 km) of battery capacity within 20 minutes.

So far, Samsung SDI does not yet announce any news of mass production on .

So what’s the battery Advantage of

1 Battery Density will increase

According to Tesla, Power density of goes up to 300 Wh/kg, which is about 20% more than current batteries that rates at 250Wh/kg. so apparently battery power density is better than batteries, as it can increase by 20% or more Compared with .

2 Battery Pack Price Decrease By 9%

Tesla further reveals the price of the lithium battery pack(with BMS) is expected to be sold for 155 USD/kWh, while size battery pack about US $185/kwh, that’s why you can notice a drop in prices by 9%.

3 More Miles to Go

Samsung said that after it was switched to the new batteries, the battery pack could reduce about
10% of its weight compared to the current battery design. By reducing EV battery weight, and the vehicle’s energy density would be also improved, from this point of view, the EV car can go miles more.

The Shortcomings of battery
The biggest problem for is: Can the downstream market accept such a size change?

What type of battery cells do Battery manufacturers produce will be subject to a variety of factors. At present, the EV industry utilizes a strategy called “positive research and development”, requiring the design of the functional structure, which also determines the use of the boot to reverse the battery models and specifications, so the battery model is mainly to see whether the replacement of the downstream market.

Battery experts believe that Tesla’s approach is not necessarily suitable for all battery business, the battery size should not change the main application of the downstream terminal as apparently there is no market demand. The current world there is a lot of market space and the scope of application, so the large size of the cylindrical battery to also

But it takes a long time.

cells have wide application usages like electric vehicles, 3C, UAV, power tools, and other areas,

but for the , there is no respective industry chain to use these batteries, which will undoubtedly increase the cost.

Are you interested in learning more about Lithium Cells? Contact us today to secure an expert consultation!