How to Prolong Life of a Lithium Ion Battery

How to Prolong Life of a Lithium Ion Battery

Lithium ion batteries are not like most other types of batteries. They have no memory, but they are sensitive to partial discharges and topping off the charge. These actions do not reduce the battery’s lifespan, and can even help it last longer. The most important thing to remember is that you should never overcharge or undercharge the battery.

Low rate of charge

It is important to maintain a low rate of charge on lithium ion batteries to prolong their life. High currents lead to capacity loss and reduce cycle life. In addition, constant charge-discharge rates decrease battery life. A graph illustrating these three factors can be seen below.

Lithium batteries last longer when stored at a cooler temperature. This is because the lithium powder increases its resistance when exposed to colder conditions. If a camera battery is to be stored for a long time, place it in a refrigerator. Likewise, if you are storing an e-bike battery, place it in the coldest part of the storage area. After storing, warm the battery to room temperature before charging.

When lithium ion batteries are recharged, they are charged to a maximum of 4.20V/cell. However, it is possible to reduce this to a lower level. A typical lithium ion cell that is charged to a lower voltage will last for about two times as long as one that is charged to the maximum voltage.

Lithium ion batteries need to be recharged frequently. Charging them too frequently or too low can decrease the battery’s capacity. It is best to store them between 40% to 80% of their original charge. This will reduce capacity loss over time and preserve the battery’s life.

Partial discharges

Partial discharges are beneficial for lithium ion batteries, but they also pose some risks. The first problem is that the battery can become overcharged, leading to damage. This happens because the active chemicals inside the cell expand, the electrolyte gasses out, and internal pressure increases. This can lead to catastrophic failure. In addition, the overcharging can cause the cells to become weaker, meaning they may not be able to fully charge.

Partial discharges can be helpful in prolonging the life of lithium ion batteries, but they should never be done intentionally. Lithium ion batteries are very sensitive, so partial discharges should only be done on a small percentage of the total capacity of the battery. In addition to this, the battery is stressed by high temperatures and high currents, so avoiding prolonged full state-of-charge cycles can prolong battery life.

The depth of discharge determines the number of cycles a battery will yield. In general, the lower the DOD, the greater the life. However, some cell chemistries require as much as ten charge-discharge cycles to produce the desired microstructure.

Lower rate of discharge

Various factors such as the rate of charge and discharge affect the battery’s performance. Higher rates of charge and discharge reduce the life of the battery. Moreover, the cycle time of the battery is also affected. For this reason, it is important to choose a battery with lower rate of discharge.

To prolong battery life, users should not charge the battery faster than 1.5C. This is because a higher discharge rate will result in a faster degradation of the battery’s capacity. Higher charge and discharge rates also lead to damage of the battery’s electrolyte.

The lower rate of discharge extends the cycle life of lithium ion batteries. By limiting the rate of discharge, users can get longer battery life by using larger capacity cells. Another way to improve the life of a lithium ion battery is to top up the battery before it completely discharges. This is possible with “microcycle” cells. These cells require small current discharge and charging pulses and can have a cycle life of 300,000 to 500,000 cycles.

Typically, Li-ion batteries are charged to a maximum of 4.20V per cell. Every reduction in this voltage of the battery by about 0.10V doubles the cycle life. For example, a battery that is charged to 4.0V can deliver 1,200-2,000 cycles. A lithium ion battery that is charged to 4.10V/cell has twice as many cycles as a battery charged to a higher voltage.

Temperature

Lithium ion batteries are highly sensitive to temperature and can be damaged by excessive heat. To prolong battery life, keep the temperature at or below 0degC. High temperatures reduce charge acceptance and deviate from the 100% efficiency line. Moreover, they increase internal resistance, reducing battery life.

Researchers have demonstrated that a battery’s aging rate increases with temperature. This increase in temperature exacerbates the rate of chemical reactions in the cell, which can lead to irreversible damage if the state of charge falls below 80%. In addition, high temperatures cause physical defects. Hence, they should be used with caution.

The best temperature range for lithium ion batteries is 85-65 degrees Celsius (SoC). This temperature range enables the longest cycle life, with about 90,000 energy units. However, this range only uses 60 percent of the battery. This discrepancy can be explained by differences in battery quality or testing methods. However, high temperatures result in faster capacity loss than low temperatures.

The rate of charge and discharge can be optimized by lowering the C rate. However, high rates can decrease battery life by increasing internal resistance. Additionally, high current and voltage will cause the battery to age more rapidly. Moreover, high temperatures may affect the shape of the battery. Low temperatures cause the electrode to contract, while high temperatures cause the electrolyte to expand.

Recovering isolated lithium

A new discovery could extend the life of isolated lithium ion batteries. The lithium metal within the battery can move back and forth between its anode and cathode. The scientists believe that this response may be due to the way lithium metal reacts to the electric field in the electrolyte. To find out if this behavior would occur in real life, they created an optical cell with a lithium cathode and an isolated island. This allowed the researchers to track the island’s movement back and forth during the charging and discharging processes of the battery.

The study was funded by the DOE Office of Energy Efficiency and Renewable Energy’s (DOER) program, which supports research on battery materials and development of more reliable batteries. The team also conducted computer simulations and validated the results using other test batteries. Their results were later published in the journal Nature.

The degradation process of lithium batteries can be complex, and there are several causes. For example, batteries may suffer from capacity loss and fires. Another common problem is the formation of islands of inactive lithium. This occurs when lithium dendrites do not dissolve uniformly. In addition, the lithium becomes electrochemically inactive. The researchers were able to revive the isolated lithium to increase the battery’s capacity.

High-voltage cycling is driving force for intragranular cracks

High-voltage cycling is a major factor driving intragranular cracking in lithium ion batteries. These cracks affect the cycle life of the battery by compromising the structural stability of the cathode. Although the causes of intragranular cracks are not yet fully understood, theoretical models predict that the cracks develop at the interface of grain boundaries and particle surfaces. To mitigate this problem, battery manufacturers should focus on using stable cathode materials and carefully controlling cycling conditions.

The main problem with present-day NMC cathodes is that they are insufficient for high-voltage operation because the performance rapidly declines after high-voltage cycling. The particle structure of the cathode consists of microscale spherical particles. These particles are polycrystalline and have grain boundaries which cause cracking upon high-voltage cycling. Moreover, the particles contain a protective polymer coating that protects the smaller particles within.

Moreover, the cracking characteristic is also highly reversible within a certain range. However, when the change is too large, irreversible cracks and dislocations are generated. These characteristics negatively impact the capacity of the battery. Therefore, it is important to properly control the charge voltage of the NMC material to minimize the occurrence of electrochemically induced intragranular cracks.

Using a battery regulator

One of the ways to improve the life of a lithium ion battery is by regulating its charge. Lithium-ion batteries, like most batteries, degrade over time, but if you don’t overcharge them, you can significantly extend their life. In addition, regulating the charge of a lithium-ion battery is a safer and more efficient way to recharge it.

Lithium-ion batteries are designed to charge at a constant 4.20V, but any voltage below that will reduce their capacity and shorten their life. Moreover, a reduction of 70 mV in the charge voltage reduces the usable capacity by about 10%. Fortunately, lithium-ion batteries can be recharged at higher voltages, but the capacity decreases with each successive reduction.

A battery regulator is an electronic device that helps regulate the charging and discharging of lithium-ion batteries. Unlike alkaline cells, lithium-ion batteries are not tolerant of high or low charging conditions, which is why many modern batteries come with a charge controller. By controlling the charge, a battery regulator can prevent a tablet from overcharging and deep-discharging.

Lithium-ion batteries are pre-charged to their maximum capacity when new. This makes it easy to extend their life by charging them slowly and more gently. However, if you’re only using your battery for a few months, then you don’t need to pay too much attention to the charging process. Once every couple of months, you can run a full charge/discharge cycle to ensure the capacity meter is accurate.