Lithium Polymer vs Lithium-ion Batteries: Which One is Better?

Portability is the need of the hour for almost all electronic devices. It has given rise to the production of various types of batteries. They have different shapes, designs and characteristics. But the most popular ones among them are lithium polymer and lithium-ion batteries. Almost all portable devices, like smartphones, have lithium batteries in them. But in more advanced devices, Li-Po is being used. Modern flagship gadgets are also using these batteries.

Both batteries have their pros and cons. But they have certain differences as well. You must understand both before considering buying any of them. Let’s take a detailed look at both of them and see which one is better.

What is a Li-ion Battery?

A lithium-ion battery is an advanced type of battery that you can recharge. It has high energy density as well. Li-ion batteries have a low self-discharge rate and almost no memory effect. Li-ion batteries have lithium ions, which are motile. During charging and discharging, they embed and de-embed back and forth. This movement is in between the two electrodes. 

Lithium ions leave the cathode during charging and enter the anode through an electrolyte. As a result, the anode becomes a lithium-rich state. The opposite of it happens during discharging. The anode comprises a “carbon layer compound,” while the cathode is a “lithium compound.” Most electric devices, as well as electric vehicles, are using li-ion batteries. Nowadays, aerospace applications are also using lithium batteries.

Pros of Li-ion Battery

Just like any other battery, Li-ion batteries have some pros and cons. Here are some of its pros:

High Energy Density

One of the best things about Li-ion batteries is their high energy density. It is the reason why manufacturers use them in solar systems, EVs and 3C products. All these devices need small size and large capacity for the battery. And li-ion batteries have these characteristics. So, these batteries are suitable for such devices.

Low Maintenance

Li-ion batteries do not require much maintenance. There is no need to add acid on a regular basis. If not charged properly, there is no such risk of bulging either. Due to this, they are quite handy. As a result, the cost of maintenance is almost nothing. It makes Li-ion batteries less expensive and cost-effective.

Low self-discharge rate

The discharge rate of different batteries varies depending on their design specifications. But Li-ion batteries have a lower self-discharge rate. When you store it in a non-use stage, no chemical reaction occurs inside it. It makes the battery stable also. And this feature is what sets Li-ion batteries apart.

These batteries have no memory effect either. You can charge them as many times as you want. There is no effect of it on the service life.

Li-ion batteries have various specifications based on different applications. You can specify the product and see if it is useful.

Cons of Li-ion Batteries

Some of the cons of Li-ion batteries are as follows:

They Require Protection!

No other kind of battery can beat a Li-ion battery in fast charging. They also have a long life. However, they may overcharge and overheat if you don’t charge them properly. It may result in safety accidents as well. So, overheating protection is a must in Li-ion batteries. Or else you may face the consequences.


Li-ion batteries are 30% more expensive as compared to other batteries. So, not everyone can afford to have it. We may see cheap Li-ion batteries in the market anytime soon. But that doesn’t seem to happen for now.

What is a Lithium Polymer Battery?

You may categorize Li-ion batteries into three different types. These include cylindrical, polymer and prismatic. A lithium-polymer battery is also a rechargeable battery. It works in the same way as a Li-ion battery does. The only difference is that it uses a polymer, solid, dry and gel-type electrolyte. In contrast, traditional Li-ion batteries use liquid electrolytes. The specific energy of these batteries is high. It means they are mostly used in devices where weight plays a role. This includes radio aircraft.

Pros of Li-Po Battery

Following are some of the advantages of Li-po battery:

High Energy Density

The energy density of Li-po batteries is almost double that of other batteries. It means it can provide higher currents for all kinds of devices. Moreover, it is a rechargeable battery. So, charging again and again won’t affect it much.


Li-Po batteries also require less maintenance, just like Li-ion batteries. It makes the battery easy to use and hassle-free. The internal resistance is also smaller in these batteries. It decreases the self-discharge rate of the battery as well. Such batteries are also useful for remote control models.

Better Safety Performance

This type of battery uses “aluminum-plastic flexible packing” material. It is different from those of metal shells used in liquid batteries. Also, the use of polymers won’t let the battery explode. So, the battery itself has enough safety. Liquid batteries tend to explode in the case of safety hazards. But that’s not the case with Li-po batteries.

Cons of Li-Po Battery

Here are some of the cons of lithium polymer batteries:


Lithium-polymer batteries are quite fragile. So, it would help if you had a circuit to make it work in a safe manner. Overcharging it may damage the reversibility of the substances inside it. As a result, its performance may be affected. Also, overheating the battery may cause problems.

Less Versatility

Batteries must have a versatile design and features. That’s the only thing manufacturers also look for these days. Li-po batteries are not versatile. The reason is that they can add or reduce cells’ thickness depending on the needs. Apart from that, these batteries are quite expensive as well.

To reduce voltage and internal pressure, you need safety mechanisms also. As a result, the weight of the battery would increase.

Sleek Design

One of the advantages of Li-po batteries is that they are lighter in weight. But they have a sleek design, which may get affected at any moment. Also, both li-ion and li-po batteries are portable. So, anyone who wants to buy batteries will go for Li-ion batteries.

All in all, Li-po batteries are good but have certain disadvantages. So, it is better to go through them before considering buying them.

Which Battery Lasts Longer?

The battery life is important to consider while comparing lithium-ion and lithium-polymer batteries. The latter has a good lifespan. It lasts up to 1,500 charge cycles. A charge cycle is from when the battery is fully charged to when it becomes dead. In comparison, Li-ion batteries last up to 4000 charge cycles. So, their lifespan is greater than Li-po batteries. 

The memory effect isn’t there in any of these batteries. But, the charge cycles are different due to their specifications. But at the same time, you’ve to avoid overheating and overcharging the batteries as well. So, it’s obvious that lithium-ion batteries are better. Their lifespan is also greater. And you can rely on them without thinking twice.

Which Battery is Better among the two?

Lithium-ion and lithium-polymer batteries are different in many aspects. For example, Li-ion batteries use a liquid electrolyte. At the same time, Li-po batteries use polymer electrolytes. Their shapes are also different from each other. Li-ion batteries can produce more power than Li-po batteries. Besides that, the cost of the lithium-polymer battery is also more than that of the Li-ion battery. But it also depends on the voltage and quality of the battery.

If we talk about capacity, Li-ion batteries are better. They can store and provide as much current as you need. But that’s not the case with lithium-polymer batteries. Moreover, you can use Li-ion batteries in EVs, UPS and solar storage systems. You can also use them in digital cameras, power tools and other portable devices. In contrast, Li-po batteries are useful for alarm systems and lights. By this comparison, it’s obvious that Li-ion batteries are better in every aspect. 

The use of a battery also depends on what you need it for. You may need a Li-po battery to meet your needs. But that doesn’t decrease the importance of Li-ion batteries.

Many companies are working these days to make solid-state batteries. And we may expect a better future for Li-po batteries also. But for the time being, there is no competitor of Li-ion batteries. So, even though a Li-ion battery is better, you’ve to make the choice.


Each battery has its specifications. You must go through them to decide if you want to buy that battery. Both lithium-ion and lithium-polymer batteries are better in many aspects. But they have certain differences also. One has high power density, while the other one is cheap. One uses a liquid electrolyte, while the other uses a solid or polymer. One has more safety concerns than the other. So, you’ve to consider all these factors before planning to buy any of these. So, research properly and then see which one is more beneficial. Or else you may end up choosing the wrong set of batteries.

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