A lithium-ion (Li-ion) battery is an advanced battery technology that uses lithium ions as a key component of its electrochemistry. During a discharge cycle, lithium atoms in the anode are ionized and separated from their electrons. Li-ion batteries consist of largely four main components: cathode, anode, electrolyte, and separator. Every single component of a Li-ion battery is essential as it cannot function when one of the components is missing.
The anode and cathode store the lithium. The electrolyte carries positively charged lithium ions from the anode to the cathode and vice versa through the separator. The movement of the lithium ions creates free electrons in the anode which creates a charge at the positive current collector. Lithium-ion batteries are currently used in most portable consumer electronics such as cell phones and laptops because of their high energy per unit mass relative to other electrical energy storage systems.
Lithium-ion batteries have one of the highest CE ratings out of all types of rechargeable batteries at 99% or higher. These are the most efficient batteries. Lead acid batteries are lower at about 90%, and nickel-based batteries are closer to 80%. These efficiencies drop at high charge rates. Most lithium metal batteries are non-rechargeable and are used in film cameras. Lithium-ion packs are rechargeable and power laptops, cellular phones and camcorders.
