Lithium-Ion vs Lithium Polymer: Which Batteries Are Best?

Battery technology moves incredibly fast, and for the most part, the general public isn’t privy to the changes being made and the exact differences between battery types, which can be a problem.

If we don’t know why one battery is better than another, and both can be found in modern electronics, how are we to figure out which will serve us best?

Lithium-Ion Vs Lithium Polymer Which Batteries Are Best

Well, to help you out of this consumer conundrum, I’m going to be breaking down the differences between two of the most commonly used battery types, lithium-ion (Li-Ion) and lithium polymer (Li-Po), and answering the all-important question… which is best?

What’s The Difference Between Lithium-Ion And Lithium Polymer Batteries?

Both lithium-ion and lithium polymer batteries have the same general construction.

We have the positive electrode at one end (usually marked with a “+”), the negative electrode at the other (indicated by a “-”), and in between these poles, we have a chemical electrolyte housed in a rigid enclosure.

It’s in the latter of these three structural similarities that their main difference is observed: type of chemical electrolyte.

Lithium-ion batteries typically make use of a liquid chemical compound, a concoction of lithium salt and an organic solvent. Lithium polymer batteries, on the other hand, use one of three alternative forms of electrolyte.

In the early days, prototypical Li-Po batteries used a dry solid, but it’s unlikely you’ll ever come across a modern variant with this form of electrolyte, as it was largely phased out in favor of a porous chemical compound.

The final evolution of the lithium polymer blueprint came in the form of a gel-like electrolyte.

Gel offers greater thermal stability than the previous two options, and fantastic capacity retention, which is why batteries of this type are being put to use in top-of-line laptops and electric cars.

Okay, So Which Battery Is Best Overall?

Both lithium-ion and lithium polymer batteries have their benefits and drawbacks, so it’s not really a question of which is best overall, but which is more suited to the application you have in mind.

Lithium-ion’s big W is its supreme power density, which is to say – although they’re heavier than their Li-Po counterparts – they have a stacked energy-to-weight ratio, so if you’re looking for optimal power, lithium-ion is the way to go.

Another feather in the Li-Ion cap is the price tag. This kind of battery is much cheaper to produce than a lithium polymer variant, which translates into savings for us, the consumers — hooray! 

The zero-maintenance design of Li-Ion batteries is a big bonus as well. Plus, these things are total workhorses! The average lithium-ion battery will last 300–500 life cycles, which equates to roughly 2–3 years, and that’s nothing to scoff at!

Lithium-ion batteries are also insanely reliable when it comes to voltage consistency. No matter how the load changes, their output is always rock-steady, which is particularly helpful when it comes to sensitive electronics, but these batteries aren’t all good.

Li-Ion power cells are known to be one of the most unstable variants on the market. Their fragility increases the chances of electrolyte leakage, which can cause a combustive chemical reaction — not the sort of thing you want in your back pocket, ay?

It’s not just their physical fragility that concerns consumers, either, but their lack of thermal resistance. When they get too hot, these batteries can quite literally pop… again, not something you want to keep on your person.

In fact, many devices that use lithium-ion batteries have been banned from flights for this very reason.

Now, that’s not to say that your lithium-ion gadgets and gizmos are going to suddenly start exploding. These batteries are usually fitted with an electronic controller that regulates heat and prevents anything from going BOOM, but their instability should still be noted.

One final drawback to the Li-Ion formula is that, although they last for an exceedingly long time, their efficiency does dwindle over the course of their 300–500 life cycles.

Lithium polymer batteries, on the other hand, are incredibly robust. They don’t use a liquid electrolyte, so there’s zero chance of leaking, and their tough yet flexible aluminum enclosures protect them from hazards.

In the absence of heavy metals and liquid, they’re a lot lighter (and smaller) than their ionic cousins, too, making them the perfect choice for the ever-shrinking technological devices of today and tomorrow. If portability is at all a concern, then Li-Po batteries are absolutely the one to go for!

They’re also a more versatile invention. Manufacturers can modify their size and shape effortlessly to fit near enough any device.

Then there’s self-discharge to consider. All batteries suffer a certain amount of discharge when not in use, but Li-Po batteries minimize this drain, ensuring you actually use the lion’s share of their stored energy. But, alas, lithium polymer batteries are far from perfect themselves.

They may be a lot smaller than lithium-ion batteries, but their price tag is significantly larger, and being that they’re not quite as power-dense and have a shorter lifespan than Li-Ion batteries, it can feel like you’re paying more for less.

Should You Be Team Ion Or Team Polymer?

There’s no question that lithium polymer is the most in-demand form of battery in the tech market at the minute due to its customizability and enhanced safety, but ion batteries are still ubiquitous in day-to-day life, so my advice is to invest in quality versions of both batteries.

Here are a few of the best lithium polymer batteries on the market…

  • EEMB 3.7V Lithium Polymer Battery — This 3.7-volt rechargeable lithium polymer masterpiece is perfect for powering things like sound machines, Bluetooth speakers, and a whole host of other small electronics.
  • C Inverter Portable Generator — If you’re looking for something a little larger to take with you on your wildlife adventures, this portable power station from C Inverter should hit the spot.

And to finish off, let’s take a quick look at some quality lithium-ion options…

Brett Jones