What Is The Composition of Polymer Lithium Battery?

What Is The Composition of Polymer Lithium Battery?

1. Cathode (Positive Electrode)

• Made of a lithium metal oxide, such as lithium cobalt oxide (LiCoO₂), lithium iron phosphate (LiFePO₄), or lithium nickel manganese cobalt oxide (LiNiMnCoO₂, NMC).

• Acts as the source of lithium ions during discharge and absorbs them during charging.

2. Anode (Negative Electrode)

• Typically composed of graphite or other carbon-based materials.

• Stores lithium ions during charging and releases them during discharge.

3. Electrolyte

• A polymer-based gel electrolyte containing lithium salts (e.g., LiPF₆, LiBF₄).

• Facilitates the movement of lithium ions between the cathode and anode.

• Unlike traditional liquid electrolytes, the polymer gel reduces the risk of leakage and enhances flexibility.

4. Separator

• A thin, porous polymer film (e.g., polypropylene or polyethylene).

• Prevents direct contact between the cathode and anode, avoiding short circuits.

• Allows lithium ions to pass through while blocking electrons.

5. Pouch or Flexible Packaging

• The battery is encased in a soft polymer pouch instead of a rigid metal casing, making it lightweight and flexible.

• The pouch is sealed to protect the internal components from external damage and to prevent air or moisture ingress.

6. Current Collectors

• Aluminum foil for the cathode and copper foil for the anode.

• Facilitate the flow of electrons between the battery's electrodes and external circuits.

Additional Features

• Some LiPo batteries include protection circuits to prevent overcharging, over-discharging, or short-circuiting.

• Additives in the electrolyte or electrodes may be used to enhance performance or safety.

Key Characteristics

• The use of polymer materials allows for thin, lightweight, and flexible designs.

• LiPo batteries are widely used in applications requiring high energy density and compact form factors, such as drones, smartphones, and RC models.