Lithium-ion batteries have become ubiquitous. They’re in your phone, computer, car, lawn tools, and even your RV. But what is a lithium-ion battery? And what’s inside a lithium-ion battery that allows it to power your electronics? Let’s take a look!
What is a Lithium-Ion Battery?
Lithium-ion batteries use lithium ions to create an electrical potential between the positive and negative sides of the battery, known as the electrodes. A thin layer of insulating material called a “separator” sits between the two electrodes and allows the lithium ions to pass through while blocking the electrons.
While the battery charges, lithium ions move through the separator from the positive side to the negative. Then, the ions move in the opposite direction while the battery discharges.
The movement of the lithium ions causes an electrical potential difference called “voltage.” When you connect your electronic devices to the battery, electrons (not lithium ions) flow and power through your device.
Battery Vs. Cell
Multiple lithium-ion cells connect internally to make up a lithium-ion battery. Think of lithium-ion cells as the building blocks of a full battery.
The voltage of a lithium-ion cell varies depending on the particular chemistry type. The nominal output voltage of a single lithium iron phosphate cell (the type used in Battle Born Batteries) ranges between 3.2 and 3.8 volts. However, the standard voltages for many lithium-ion batteries are 12, 24, and 48 volts.
When cells are connected in series, their voltages add together. For example, connecting four cells in series will yield a 12-volt battery. Wiring eight cells in series will produce a 24-volt battery, and so on.
Lithium-ion cells can also be connected in parallel. When you connect battery cells (and batteries) in parallel, their capacities add together. This means that two cells wired in parallel will last about twice as long as a single cell.
What’s Inside A Lithium-Ion Battery?
The inside of a lithium battery contains multiple lithium-ion cells (wired in series and parallel), the wires connecting the cells, and a battery management system, also known as a BMS.
The battery management system monitors the battery’s health and temperature. At the top of each charge, the BMS balances the energy across all cells and helps ensure your battery’s maximum life and performance.
Lithium-Ion Cells
The inside of an individual lithium-ion cell is relatively simple. There are four main components: The anode, the cathode, an electrolyte, and a separator.
The Electrodes: Anode and Cathode
The negative electrode in a cell is called the anode, and the positive electrode is called the cathode. The lithium ions move from the cathode through the separator to the anode during charging. During discharge, the flow reverses.
Graphite is the most popular material used for the anode in lithium-ion batteries. On the other hand, cathodes are typically made of lithium cobalt oxide, lithium iron phosphate, or lithium manganese oxide. The chemistry of the cathode material directly correlates to the battery’s chemistry.
Battery Electrolyte
The role of the electrolyte inside a lithium-ion battery is to help transport the positive lithium ions between the anode and cathode. The most common electrolyte inside a lithium-ion battery is lithium salt.
The Separator
The separator is a thin sheet of material between the anode and cathode that allows the lithium ions to pass through but doesn’t conduct electricity. It prevents the anode and cathode from shorting together electrically and forces the electrons to flow through your electronic device, giving it power.
The separator also plays an important safety role. If the separator gets too hot, the pores close, preventing the lithium ions from passing through. Stopping the transport of the ions shuts down the battery cell, which can help prevent unsafe operating conditions and damage to the battery.
How To Improve Lithium-Ion Batteries
Lithium-ion batteries have changed our world. They last much longer and store more energy than any previous battery type. However, this does not mean that manufacturers cannot improve these batteries.
Here at Dragonfly Energy, we assemble the highest quality energy storage lithium-ion batteries utilizing conventional cells. While this technology changes the energy storage world, we’re not stopping there. We are actively working on the next generation of lithium-ion technology.
From working on developing solid-state batteries that last longer and pack more energy to revolutionizing the manufacturing process, our R&D team is looking to the future of energy storage.
