How Do Li-ion Batteries Work?

If you’re even vaguely interested in batteries, then chances are you have heard of the term Li-ion. This stands for Lithium-ion, and it’s now the standard for most rechargeable batteries. If you are wondering how they work and why they are preferred over other materials, then this article will answer both of your questions.

The Atom, Electron, and Ion

To understand how Li-ion battery work, it’s essential that you have some clarity on what the terms atom, electron, and ion mean. Everything you see around you is made up of atoms, billions and billions of them. Furthermore, the atom has three primary constituents: electron, proton, and neutron. The electron is negatively charged, the proton is positively charged, and the neutron is neutral in charge.

The protons and neutrons form the core, and the electrons revolve around this core to maintain the atom’s stability. If you take out an electron from the atom or add one electron to it, then you get an ion. And the ion can be either positively or negatively charged.

Li-Ion Working Principle

Lithium-ion is where you have an electron added or removed to a neutral Lithium atom. Just like any other battery, the Li-ion battery has a power generating component, called a cell. There are multiple cells within a battery. The cell has three different elements: a positive electrode, a negative electrode, and an electrolyte, which is a liquid separating the two electrodes.

The two cells are made from different materials. The positive one is made up of lithium-ion phosphate, and graphite is preferred for negative ones.

When the battery charges up from an external power source, the positive electrode emits some of the lithium-ion which moves through the electrolyte medium and land on the graphite electrode. This process continues this for as long as the battery is connected to the external power source, or until the charge is complete (i.e., when no more lithium ions are left to be transferred).

When the Li-ion battery is used, the electrons move in the opposite direction back to the lithium electrode. Power discharges until all the ions move back to the electrode.

When the battery is connected to an external power source, it takes up an electric current. When it is used as a power source, it provides the electric current. And that’s the essence of how lithium-ion batteries work.

How Li-Ion Batteries Became the New Rechargeable Batteries

Batteries are chemical reactions taking place within a small metal canister. The problem with non-rechargeable batteries was that once the ions move in one direction, it’s inefficient to move them in the opposite direction even with an external power source. But ions can be separated from lithium easily, which makes them ideal for recharging again and again.

These batteries also have high energy density, which means that they can provide electric current for a more extended period without requiring a recharge. Thus, Li-Ion batteries are being adopted by mobile manufacturers and electric vehicle makers everywhere. In the coming years, we’ll see them applied in even more diverse areas.

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