Battery Energy Density

What is Battery Energy Density?

Energy density is the measure of how much energy a battery contains in proportion to its weight. This measurement is typically presented in Watt-hours per kilogram (Wh/kg). A watt-hour is a measure of electrical energy that is equivalent to the consumption of one watt for one hour.

Power density is the measure of how quickly the energy can be delivered, rather than how much stored energy is available. Energy density is often confused with power density, so it is important to understand the distinction between the two.

Why Do You Need a Battery with High Energy Density?

To better understand lithium batteries, you should understand why a high energy density is a desirable trait in a battery.

A battery with high energy density has a longer battery run time in relation to the battery size. Alternately, a battery with high energy density can deliver the same amount of energy, but in a smaller footprint compared to a battery with lower energy density. This greatly expands the possibilities for battery applications.

In factory or warehouse settings, forklift batteries can weigh thousands of pounds. A lightweight battery for forklifts offers some advantages in safety and handling.

If the energy density of a battery is too high, it could present a safety issue. When there’s more active material packed into a cell, it increases the risk of a thermal event.

Which Type of Rechargeable Battery Has the Highest Energy Density?

There are several different types of rechargeable batteries with a variety of energy densities reflective of their internal chemistry.

• Energy density of Lead acid battery ranges between 30-50 Wh/kg
• Energy density of Nickel-cadmium battery ranges between 45-80 Wh/kg
• Energy density of Nickel-metal hydride battery ranges between 60-120 Wh/kg
• Energy density of Lithium-ion battery ranges between 50-260 Wh/kg

Types of Lithium-Ion Batteries and their Energy Density

Lithium-ion batteries are often lumped together as a group of batteries that all contain lithium, but their chemical composition can vary widely and with differing performance as a result.

Most lithium-ion battery types share a similar design of a cathode with aluminium backing, a carbon or graphite anode with copper backing, a separator, and electrolyte made of lithium salt in an organic solvent.

Manufacturers have experimented with the materials used on the cathode & anode. They have also varied the composition of the electrolyte. These differences are what causes lithium-ion batteries to vary in their energy density levels.

Now we’ll review the most popular lithium-ion battery chemistries, along with their respective energy densities, use cases, benefits, and drawbacks.

Industry Titans: Lithium Titanate (LTO) Batteries

An LTO battery is one of the oldest types of lithium-ion batteries and has an energy density on the lower side as lithium-ion batteries go, around 50-80 Wh/kg.

In these batteries, lithium titanate is used in the anode in place of carbon, which allows electrons to enter and exit the anode faster than in other types of lithium-ion batteries.

This structure allows the LTO batteries to charge much faster and handle high currents safely, but the low energy density makes them poorly suited for material handling equipment.

They tend to be more expensive and are typically used for electric vehicles, car audio applications and mobile medical devices.

High Energy, High Risk: Lithium Cobalt Oxide (LCO) Batteries

Lithium cobalt oxide batteries have a high energy density of 150-200 Wh/kg. Their cathode is made up of cobalt oxide with the typical carbon anode, with a layered structure that moves lithium-ions from anode to the cathode and back.

These types of batteries are popular for their high energy density and are typically used in cell phones, laptops, and most recently electric vehicles.

Cobalt is a very energy dense material, but it can be expensive. As demand increases for use in electric vehicles, it’s a rapidly depleting resource. In fact the world could face a cobalt supply shortage soon.

Cobalt is also highly volatile. Lithium-cobalt batteries can’t handle large currents because of the risk of overheating, which is a significant safety risk. LCO batteries have lower thermal stability, which means they are highly sensitive to higher operating temperatures and overcharging.

Performance with a Price: Lithium Nickel Manganese Cobalt Oxide (NMC) Batteries

Lithium nickel manganese cobalt oxide batteries also have a high energy density of 150-220 Wh/kg. They use cobalt in the cathode just like LCO batteries, but they also contain nickel and manganese to help add stability.

NMC batteries are used in most electric vehicles in production today but are also used for medical devices and e-bikes.

The secret to this battery’s success is its well-balanced chemistry; nickel is known to be energy-dense but unstable, just like cobalt, while manganese is more stable but also lower in energy density. The specific ratio of different elements varies by manufacturer, but the addition of nickel is typically intended to allow them to reduce the amount of expensive cobalt.

NMC batteries can handle larger charge currents and a greater range in temperature than LCO batteries. However, since the battery still contains cobalt, the cost is driven up due to market scarcity.

Affordable, Safe and Reliable: Lithium Iron Phosphate (LFP) Batteries

LFP batteries have a high energy density of 90-160 Wh/kg. While that is lower than some of the cobalt batteries, it is still among the highest of all the battery types.

LFP batteries use iron phosphate for the cathode and a graphite electrode combined with a metallic backing for the anode.

Lithium iron phosphate, or LiFePO4, is a naturally occurring mineral that is inexpensive, non-toxic and has good thermal stability with high energy density.

LFP batteries are ideal for heavy equipment and industrial environments because of their ability to withstand a lot of abuse and a wide range of temperatures. They have emerged as a new go-to option in forklifts and other heavy electric equipment that needs a high level of reliability and has historically relied on lead acid batteries.

All types of lithium-ion battery chemistries are unique. It is crucial to understand which lithium-ion chemistries are best suited for your application.

If you are searching for the best battery for your material handling equipment, a lithium iron phosphate battery is likely the best choice. Of course, for RC hobby or UAV drone, high energy density of lipo battery will give you the different fly experience, they offer the best balance between safety and performance.

Grepow battery manufacturer offer the best higher battery energy density, if you have any question, feel free to email us: info@grepow.com

How to Protect Lipo Batteries for UAV Drone?

 Standard voltage of batteries is 3.0V – 4.2V (single cell), the battery during charging and discharging work, should be controlled within this range; before the battery charge and discharge, it is recommended to detect the battery voltage batteries per piece how much; Battery voltage factory within a month is about 3.8 – 3.9V (single power-saving core), the same battery pack each piece of differential voltage batteries within 20mV; The use of more than three months battery pack, battery pressure within the range of 50mV;

Batteries can stand a maximum voltage limit of 4.22V (single- power-saving core), the lowest limit voltage of 2.8V (single power-saving core), when the battery voltage is higher than 4.22V or lower than 2.8V may cause batteries charge and discharge performance and safety damage, may result in heat leakage, flatulence; for quadcopter or other operating current exceeds the 3C products (such products less resistance, primarily focused on capacity above 3.2V), the proposed discharge cut-off voltage of 3.2V, reducing the risk of over put .

How to Protect Lipo Batteries – Charging

• Charging Ambient temperature range 0 ~ + 45℃;
• The charging current must not exceed the maximum current specification identifies the general should not exceed 2C;
• The presence of bulging deformation, leakage, or battery voltage is below 2.8V phenomenon can not be charged; at room temperature before charging batteries shall not exceed 40℃;
• Charge shall not exceed the upper limit voltage 4.22V, at room temperature after charging the battery surface temperature should not exceed 45℃;
• Suggested the use of formal manufacturers, quality and reliable chargers, battery chargers have recommended balance function.

How to Protect Lipo Batteries – Discharge Precautions

• Discharge temperature range -20 ~ + 60℃
• Discharge current may not exceed the maximum current specification logo
• The presence of bulging deformation, leakage, or voltage difference≥30mV phenomenon battery is not discharged.
• Discharge voltage of not less than the lower limit of 3.0V (single power-saving core), each single cell battery voltage difference between the maximum should not exceed 150mv after large current discharge, the surface temperature should not exceed 80℃

How to Protect Lipo Batteries – Shipping

• The battery should be done to treat transport filling, crash and other measures to prevent the battery to severe shocks or vibration;
• If you find any anomaly batteries, such as batteries plastic edge damage, shell breakage, smell the smell of the electrolyte, the electrolyte leakage, the batteries can not be used for distributing the electrolyte leakage or odor electrolyte batteries away to avoid the risk of fire source.

How to Protect Lipo Batteries – Others Tips

• Non- professionals do not anatomy batteries, it may cause an internal short circuit, thereby causing the drum air, fire and other problems.
• Lithium polymer electrolyte flow does not exist in theory,but in case there is leakage of the electrolyte and contact with skin, eyes or other body parts, rinse immediately with water and seek medical attention immediately electrolyte

In any case , you can not burn batteries or batteries into fire, otherwise it will cause the batteries burn, which is very dangerous and should be absolutely prohibited batteries should not be soaked in a liquid, such as fresh water, sea water, drinks.

More about drone battery information, please check our email: info@grepow.com, we are one of the best battery manufacturer, and provide professional battery services for you.

Cited from: https://www.grepow.com/blog/how-to-protect-lipo-batteries-for-uav-drone/

Can I Fly My Drone in the Winter?

 You may have heard that there are restrictions when flying your drone in high temperatures, but did you know that it’s a similar case in low temperatures too?

We will explore some factors to consider if you plan on flying your drone in cold weather.

The impact of low temperatures on drones

Lower temperatures slow down the chemical reaction of LiPo Battery, thereby reducing battery capacity, increasing resistance, and shortening the flight time. Drone manufacturer DJI states on its website that the LiPo batteries that power their drones start draining at an increased rate at temperatures below 59℉ (15°C).

It’s important that users read the manuals for their drones before a flight.  The operator temperature of most drones is set at 32 to 104 ℉ (0 to 40°C), so you should avoid flying outside of this temperature range.

To fly a drone in low-temperature, you need to prepare in all aspects.

Measure

Before going out

Plan your day out beforehand and try to finish your flight as soon as possible before it gets too dark. See the weather forecast: if there’s snow, hail, or rain, reschedule your flight as these weather conditions can damage your equipment and drones and very likely cause a crash.

Ensure your batteries are fully charged and have spare ones on hand to switch out.

When going out

Limit direct exposure of your batteries to the cold air. Keep them in their gear or protective equipment instead of just in the trunk of your vehicle.

Take off

When launching your drone, raise the aircraft 10-20 feet from the ground and make it hover for 30-60 seconds. This can increase the temperature of the battery to achieve a warm-up effect. Some apps, such as the DJI GO, allow you to check and monitor the battery temperature.

Source: DJI

Focus on the battery’s voltage. You should keep the battery’s voltage indicator displayed on your monitor so you can keep track of it.

Check the components. In a cold environment, some parts, like propellers, become more fragile. Therefore, it is necessary to check them more diligently for cracks or damage. You can also consider replacing them with solid carbon fiber blades.

Avoid running out of capacity. Fly until the battery drops to 30-40% of its capacity, and then bring the drone back down. In order to prevent other unpredictable situations from happening, don’t drain your battery completely when flying.

Stop flying immediately if it starts to rain or snow.  Be careful because most drones are not waterproof. Moisture may short-circuit the motor and cause the drone or controller to malfunction.

For you

Don’t forget to keep yourself warm. It is best to wear gloves which can touch the screen because it will be very inconvenient to operate the device with cold and stiff hands.

Wear goggles. When flying in icy or snow-covered weather, your eyes may be damaged due to the greater light reflection. Goggles can avoid this problem.

Low temperature-resistant battery

You can also look at low temperature-resistant batteries, such as the LiPo batteries developed by Grepow, which achieves lower internal resistance and increase the discharge rate.

The lowest operating temperature is -58℉ (-50℃), which breaks the discharge limit of traditional lithium polymer batteries. These batteries can also be customized per the clients’ needs and product requirements. Go here to learn more about the discharge rate of these batteries at different temperatures.

If you’re aware of your surroundings and take things tips into account, you will be able to fly more smoothly in cold weather. Get ready to take off: the magnificent scenery is waiting for you.

Cited article "Grepow blog"