What Is a Lithium Ion Battery Pack?
A battery pack is a collection of lithium ion cells. These batteries are made up of cathode, anode, and electrolyte & separator.
The anode is a negative electrode that emits electrons. Lithium ions travel through an electrolyte solution of additives, solvents, and lithium salts to reach the anode.
The battery chemistry prefers partial discharge over deep discharge. Deeply discharging will cause the formation of an SEI which reduces cycling capacity and increases cell impedance.
High Energy Density
Unlike lead acid batteries, lithium-ion battery packs don’t require the addition of an electrolyte and are therefore maintenance-free. This eliminates the need for regular replenishment and the worry about spilled acid or hazardous vapors. Lithium-ion also has a higher energy density than competing technologies such as nickel-cadmium and nickel-metal hydride batteries.
The high energy density of lithium-ion battery packs allows them to store more watt hours in one kilogram than other types of batteries. This means that they can be used in a wide range of applications, from powering electric vehicles to providing emergency backup power for your home.
SWE’s Lithium-Ion and Lithium Polymer cells feature a maximum discharge rate of 2C (note there are select cells that can discharge at up to 30C). This enables a greater capacity for your battery pack with reduced thermal management components reducing weight, size and cost. It also allows the battery to stay cooler during discharging enabling longer cycle life.
Lightweight
With lithium ion technology, you can produce more voltage per cell than other secondary batteries. For example, you can store 2.1 volts in a lithium battery pack whereas a lead-acid battery produces only 1.2 volts and a nickel-metal hydride battery produces 1.25 volts.
These batteries also hold their charge much better than other battery types. Lithium batteries only lose 1% to 2% of their charge per month, while nickel-metal hydride batteries typically drop 10% a month or more. They can even be re-charged hundreds of times without losing their ability to hold a charge, making them an excellent choice for backup or emergency power.
Additionally, their lightweight nature allows for more energy storage in a smaller space. This allows for more compact and portable devices – from laptops and mobile phones to hybrid and electric vehicles – to be made feasible.
Long Lifespan
Unlike nickel-metal hydride batteries, lithium ion battery packs hold their charge for longer and lithium ion battery pack don’t lose more than 5% of their capacity each month when stored. However, the lifespan of a lithium battery depends on how they’re handled and charged.
Proper storage of a lithium battery pack can significantly increase the number of cycles and lifespan it experiences. In general, a lithium battery can deliver up to 500 full charges and discharges, or around 2 to 3 years of use.
This lifespan is based on the chemistry and temperature. The ion movement between the positive and negative electrodes is not limited, but cycling, elevated temperatures and aging decrease its performance. To prolong battery life, a battery should be charged at normal rates and avoid overcharging. It should also be kept at a cool temperature to prevent the internal resistance from rising, which reduces the overall energy of the battery. This information is important for understanding how to maximize battery life and reducing the frequency of replacements. This will allow customers to save money and ensure the battery is always ready for usage.
High Rechargeability
Lithium batteries store a lot of energy in a small volume. They are capable of storing up to 150 watt-hours in one kilogram of battery. This makes them an excellent choice for electronics like MP3, digital cameras and mobile phones. They also have a low self-discharge rate, which means they retain their charge much longer than traditional batteries like nickel-metal hydride batteries.
During discharging, lithium ions in the anode move through the electrolyte to the cathode, where they recombine with their electrons. This recombination releases electrical energy, which the external circuit converts into chemical energy and stores in the cell.
During charging, an external electrical power source applies a voltage greater than the cell’s own to force electrons to move from the positive to the negative electrode. The external circuit then converts this energy into chemical energy and stores it in the cell’s porous electrode material by insertion (intercalation) or extraction (deintercalation). This battery technology is widely used in consumer electronics, electric cars, laptop computers and even grid-scale energy storage.
Safety
Lithium batteries have a very high energy density but that comes with a cost. When a lithium battery pack is damaged or overheated, it can explode.
To help prevent this, lithium ion battery packs have safety circuits built in to protect the cells from overcharging and overheating. These circuits also monitor the battery temperature and voltage to help prevent overheating or a short-circuit. They may even have cooling provisions.
Unlike nickel-based batteries, which can bike battery be used safely by hobbyists on their own, lithium batteries need to be assembled into battery packs and regulated by a battery management system (BMS). These systems track the data from all the individual cells within the pack to ensure that the pack is working correctly and safely.
Be sure to check your device for warning signs like swelling or puncture, strange odors, excessive heat, or white or gray wispy smoke. Follow your home fire escape plan and get out quickly if you notice any of these warnings. And always recycle your batteries and chargers properly. Don’t put them in the trash, where they can end up contaminating the environment with pure lithium metal, which is very dangerous.
