The Lithium ion vs Lithium polymer batteries debate has been around for a bit now. Now while most consumers may not really be bothered. It would be interesting to know which is the better choice and why?

A Lithium ion battery

Lithium ion (Li-ion) batteries have been around now for over 30 years. First adopted by Sony, Lithium ion batteries went on to conquer the world. For many years, they were the undisputed battery of choice, till a new successor showed up. It was a battery with very similar characteristics. This newer battery is known as Lithium polymer (Li-po).

A typical Li-po battery

The Lithium ion Vs Lithium polymer batteries debate is seen by many tech insiders as nothing but sibling rivalry. This is very true because both batteries are virtually identical apart from some very few key aspects.

So now we are going to look at both batteries head to head.

Read: Read: Types of smartphone batteries

Lithium ion vs Lithium polymer

Anode and Cathode

Both batteries actually use the same build materials. Both batteries use Lithium Maganese di-Oxide (LMNO), Lithium Iron Phosphate (LiFePo) or Lithium Cobalt Oxide (LiCoO) materials for their cathodes. For the anodes, Zinc or Carbon (Graphite) are the preferred metals of choice.

There is nothing to separate them here.

Electrolyte

Li-ion batteries use a liquid electrolyte in the form of a carbonate while Li-po batteries use solid electrolytes in the form of gels/pastes.

Protection circuit

A protection circuit is a printed board at the top of the battery where it connects to the phone. It is designed to protect the battery against current overload, overcharging and ultimately exploding. Both Li-ion and Li-po batteries can potentially explode if handled incorrectly and are potential fire hazards. It is pertinent to note that it is rather rare for batteries to explode.

Recent examples of exploding phones include the infamous Samsung Galaxy C4, I mean Note 7 that had to be recalled after several spontaneously exploded.
Zach did a video on it and it is a good watch.

Weight

Although both batteries do not weigh much, the Li-po battery is the lighter of the two.

Self-discharge

Self-discharge is when a battery that is not in active use loses current (power). So if you have a phone that was fully charged (100%) by 8am. You then put it in your bag and go to work. By 12 noon you take it out of your bag to check social media and bam! There is only 80% of battery left, such a phone has a self discharging battery.

Both Li-ion and Li-po batteries self discharge but the Li-ion battery has a much higher rate of self-discharge when compared to Li-po batteries.

Read: A brief overview on Smartphone batteries

Body/Form factor

Li-ion batteries come in a strong metal case and are usually rectangular in shape. Li-po batteries on the other hand are safer with their gel/paste electrolytes and do not need a protective case. They come in a polycarbonate/polymer pouch and can take any shape or form. Li-po batteries use the body of their host phones for extra protection.

This ability of Li-po batteries to take any shape and form have made it possible for the variety of new shapes and forms of smartphones that we see today. It has also helped make smartphones slimmer and thinner.

Energy density

Li-ion batteries have a higher energy density that Li-po batteries which is most likely due to its shape and form factor.

Shelf-life

Li-ion batteries can still be found today in large quantities in shops because they have a long shelf life and their form factor and casing protects them from the elements and age. Li-po batteries on the other hand have a shorter shelf life when compared to Li-on batteries.

Price

Li-ion batteries are actually more cheaper to produce than Li-po batteries. This can be chalked up to the fact that the technology for producing Li-ion batteries have been around for a long time now. This means that cheaper and more efficient means of production have been devised over time.

Final verdict

Li-ion and Li-po batteries both share similar characteristics, but also differ in other aspects. Li-ion batteries have higher energy density, are cheaper and live longer on shelves. Li-po batteries have lower self discharge, are lighter and can take any shape or form. These qualities have made them both, the darlings of the industry today.

The choice of Li-ion or Li-po batteries on a smartphone are actually out of our hands. That decision rests with the smartphone manufacturer. If you are buying an iPhone or a Samsung Galaxy phone, then it’s going to have a Li-ion battery. On the other hand, Xiaomi, Oppo and Huawei phones use Li-po batteries.

Thank you for reading to the end. As always, ensure to check out our links for more information and…