Advantages of a Lithium Battery Pack
Lithium battery pack have a high power density, making them perfect for customer mobile electronic devices. Hundreds to thousands cells are combined in parallel and series to achieve a specific voltage and capacity.
PCM absorbs and releases heat by evaporation to cool the battery and improve temperature consistency . It’s also cost-effective compared to liquid cooling systems.
High Energy Density
The energy density of a battery pack is the amount of electrical energy it can store per unit of volume. This is a key consideration for electric vehicles where the batteries are located in a limited space. A battery with high energy density can travel farther on a single charge.
Lithium-ion batteries can store up to 150 watt-hours of electricity per kilogram. That is three times more than other rechargeable battery technologies, such as nickel-cadmium or nickel-metal hydride.
They are also much lighter, making them easier to carry and install in EVs. They are also able to be charged and discharged many times without damaging the cell. The lithium ions in a Li-ion battery are not stored as metals, which makes them a safer alternative to other rechargeable batteries.
However, lithium-ion batteries are still prone to fires when they overheat. Those fires can be caused by internal shorts that trigger the venting of organic solvents used as electrolytes in lithium-ion batteries. That can cause an explosion or a fire that can destroy the whole battery pack and surrounding structure.
As lithium ion batteries are made of lightweight elements like lithium and carbon they offer much higher energy density than other rechargeable battery types Li-ion battery pack such as NiMH (nickel-metal hydride). Lithium ion battery packs can hold about 150 watt-hours per kilogram, which is more than double the amount that a similar sized NiMH pack can store.
Unlike traditional lead acid batteries that degrade rapidly with each charge-discharge cycle, lithium ion batteries are long-lasting. Their lifespan is typically described in terms of the number of complete charge-discharge cycles a battery can achieve before it reaches its failure point in the form of capacity loss and impedance rise.
Keeping lithium batteries at the correct state of charge and storage conditions helps prolong their lifespan. Batteries should be stored between 40% and 60% of their full capacity. This prevents the electrodes from becoming depleted of lithium ions, which leads to decreased cycle life. When a battery is not in use it should be regularly charged to keep its charge at the optimal level. Each reduction in peak charge voltage lowers cycle life by 10 percent.
A lithium-ion battery pack has significantly lower operational and maintenance (O&M) costs than other technologies such as lead acid. These costs include the cost of the batteries themselves as well as all the infrastructure required to install and operate them safely.
Lithium-ion also has a much lower self-discharge rate than other types of batteries, such as lead acid and nickel based ones. This means that a Li-ion battery pack will retain a full charge for up to a year with very little loss of performance.
Battery prices have fallen dramatically in recent years, but they could be on the rise again. That is the main takeaway from Bloomberg New Energy Finance’s (BNEF) 2022 Battery Price Survey, which cited higher raw material prices as the reason for the price hike. Cells make up 83% of EV battery pack costs, according to the report, and are particularly sensitive to Li-ion battery pack pricing volatility for key ingredients like cobalt and nickel. That could push back the point when EVs achieve price parity with gasoline vehicles and hurt the economics of battery energy storage projects.
Fast Charging Rate
A lithium-ion battery pack can be charged at an ultra-fast rate, but the individual batteries within it must be designed to withstand such stress and have ultra-low resistance. The cells must be well matched and in good condition with an end-of-charge voltage set at about 70 percent to avoid excessive stress on weaker cells.
Most lithium-ion batteries are designed to charge at a rate called 1C, meaning that it takes one hour to reach a full charge. This is the charging rate that many consumers and forklift manufacturers assume when purchasing a battery.
However, such a sheltered lifestyle does not always reflect real-world situations where small packs must be charged quickly and deliver high currents. Such conditions could induce dendrite growth and shorten battery cycle life. Nevertheless, the Stanford researchers’ simulations have shown that a battery managed with their new method can handle at least 20% more charge-discharge cycles. This approach may prove useful in electric vehicles and drone-like aircraft, also known as eVTOLs. The latter are expected to offer air taxi services and other urban air mobility options over the next decade.
Lithium batteries have become the favoured electrochemical energy storage device for EVs and other applications. Despite their benefits they are vulnerable to the dangerous phenomenon of thermal runaway (TR) that can, through exothermic decomposition, cause fire and explosion. Improved battery safety is therefore crucial to enable widespread EV adoption.
To reduce the risk of a fire, you should keep lithium batteries away from metal objects and water. You should also be sure to check the date of manufacture, as unused batteries can lose their charge over time. Avoid overcharging your batteries, as this can damage them and lead to internal short circuits.
A small number of lithium batteries can burst into flames, though this is very rare — only about two to three packs per million. This can happen due to insufficient battery maintenance or physical damage. To prevent this, your battery pack should be sealed in a metal case and contain vent holes, positive temperature coefficient resistors, and other safety features. Moreover, it is important to be present when charging the battery and to disconnect the charger once it’s fully charged.