Difference between Lithium Ion and Lithium Polymer Battery

Battery is an electronic device that converts chemical energy into electrical energy. It is widely used in various portable electronic devices and other mobile devices. Batteries are classified into two categories namely rechargeable batteries and non-rechargeable batteries.

In this article, we will explore two widely used types of rechargeable batteries namely, Lithium-Ion (Li-Ion) battery and Lithium-Polymer (Li-Po) battery and their important differences.

The primary difference between Li-Ion battery and Li-Po battery is that a Li-Ion battery provides high energy density while a Li-Po battery provides low energy density. Read this article to learn more about the Li-Ion and Li-Po batteries.

What is a Li-Ion Battery?

A Lithium Ion (Li-Ion) battery is a type of rechargeable battery in which lithium ions act as the primary charge carries. A Li-Ion battery typically consists of two main components namely, electrodes and electrolyte. It consists of two electrodes namely, anode and cathode. The anode is generally made up of graphite, while the cathode is made of lithium metal oxide. The electrolyte acts as a separator that prevent direct contact between the anode and cathode and allows the flow of lithium ions through.

The lithium ions make a movement between the anode and the cathode through the electrolyte during charging and discharging processes. The lithium ions travel from the cathode to the anode during charging process and they travel from the anode to the cathode during discharging process.

Li-Ion batteries are primarily known for their high energy density, longer battery life, lower self-discharge rate, etc. However, they also have some downsides, including sensitivity to overcharging and high temperatures that require proper charging circuit.

Li-Ion batteries are commonly used in a variety of mobiles devices, such as smartphones, tablets, laptops, automotive, etc.

What is a Li-Po Battery?

A Lithium Polymer (Li-Po) battery is another type of rechargeable battery that uses a polymer-based electrolyte. A Li-Po battery typically consists of two main parts namely, electrodes and electrolyte. It has two electrodes namely, anode and cathode. The electrolyte is a polymer material that acts as the separator between the anode and the cathode. The polymer electrolyte allows the movement of lithium ions between the anode and the cathode during charging and discharging processes.

Li-Po battery has several advantages over normal Li-ion batteries. They are primarily known for their compact design, light weight, greater flexibility, lower self-discharging rate, stable discharge voltage, and more. However, this type of battery requires a specialized charging circuit to provide a consistent charging voltage and current. They are also relatively expensive than traditional Li-Ion batteries.

Li-Po batteries are commonly used in devices and applications that require compact design and light weight, such as smartwatches, drones, and other types of remote-controlled devices and wearable devices.

After getting insights into the basics of Li-Ion battery and Li-Po battery, let us now discuss their important differences.

Difference between Li-Po Battery and Li-Ion Battery

The following table highlights all the major differences between Li-Po battery and Li-Ion battery −


Li-Ion Battery

Li-Po Battery


Lithium Ion Battery

Lithium Polymer Battery


Li-Ion battery is a type of rechargeable battery in which the Li-Ions act as the main charge carriers.

Li-Po battery is another type of rechargeable battery in which polymer-based electrolyte is used as a separator between the anode and the cathode.


Li-Ion batteries use liquid electrolyte.

Li-Po batteries use gel-like polymer electrolyte.

Energy density

Li-Ion batteries have higher energy density.

Li-Po batteries have lower energy density.


Li-Ion batteries have comparatively bigger size.

Li-Po batteries have compact size.


Li-Ion batteries are heavier.

Li-Po batteries are lighter than Li-ion batteries.

Flexibility in design

Li-Ion batteries are less flexible in terms of design.

Li-Po batteries are highly flexible, as manufactures are not bound to follow the standard cell formats.

Risk of explosion

Li-Ion batteries involve higher risk of explosion.

Li-Po batteries have lower risks of explosion, as there are less chances of electrolyte leakage.

Charging period

Li-Ion batteries have a comparatively longer charging period.

Li-Po batteries have a shorter charging period than Li-Ion batteries.


Li-Ion batteries are more less expensive.

Li-Po batteries are more expensive than Li-Ion batteries.

Internal resistance

Li-Ion battery has high internal resistance.

Li-Po battery has low internal resistance.

Conversion rate

Li-Ion batteries have higher conversion rate, typically around 85% to 95%.

Li-Po batteries have comparatively lower conversion rate, around 75% to 90%.


Li-Ion batteries exhibit higher aging-related issues, i.e. they lose their charging capacity over time.

Li-Po batteries exhibit less aging issues, allowing them to maintain their charging capacity for longer than Li-ion batteries.

Voltage stability

Li-Ion batteries typically provide less stable voltage during discharging cycle.

Li-Po batteries provide more stable voltage during discharging cycle.

Operating temperature range

Li-Ion batteries have comparatively a wider range of operating temperature.

Li-Po batteries have a lower range of operating temperature than Li-Ion batteries.


Li-Ion batteries are mainly used in portable electronic devices like smartphones, tablets, laptops, automotives, etc.

Li-Po batteries are widely used in devices that require flexible design and light weight, such as drones, wearable devices, remote-controlled vehicles, and other consumers electronics.


Both Li-Ion and Li-Po batteries have their own advantages and limitations. The important point to note about Li-Ion and Li-Po batteries is that both contain toxic materials that can impact the environment and hence they should be properly handled and recycled.

The most significant difference between lithium-ion battery and lithium polymer battery that is a lithium-ion battery uses liquid electrolyte which has higher energy density, whereas a lithium polymer battery use gel-like polymer electrolyte that has lower energy density. All these differences can help you to select the suitable battery for your specific applications.

Updated on: 07-Aug-2023


Kickstart Your Career

Get certified by completing the course

Get Started