Battery Comparison: LiFePo4 vs Lithium-Ion Batteries

High-capacity batteries are highly sought after nowadays, for a wide range of applications. These batteries serve the purpose of recreational batteries, electric vehicles batteries, solar batteries, and a lot of other uses.

Many years ago, you would have seen that lead-acid batteries were the only high battery capacity option available in the market.

However, the market today has changed considerably as the demand has tilted towards lithium-based batteries due to their uses.

In this regard, two types of batteries shine above the rest- Lithium-ion batteries and Lithium Ferrous Phosphate (LiFePO4) batteries. Since both are lithium-based, people often ask us about the differences between the two types.

Therefore, in this article, we will explore these batteries in detail and how they differ from each other. You will know about their performance on a wide range of parameters, getting a better understanding of which battery will be the right fit for you.

Without any delay, let us get started:

How Do the Chemistries of Lithium-ion Batteries and LiFePO4 Differ?

Lithium ion batteries and Lithium Ferrous Phosphate batteries both fall under the class of Lithium batteries. Therefore, the construction of both these batteries has a lot of similarities.

Lithium-Ion Batteries

Lithium-Ion Batteries

In principle, Lithium-ion batteries involve the movement of lithium ions between two electrodes in an electrolyte solution or gel.

The cathode materials are lithium-based compounds like lithium cobalt oxide or lithium manganese oxide. The anode is usually made of carbon materials, such as graphite.

Since there are many options in cathode material and the electrolyte used, many different types of lithium ion batteries are available. Some iterations use polymers instead of liquid electrolyte and are called lithium-ion polymer batteries.

A single battery cell of a lithium-ion battery typically generates a voltage of about 3.6V. To create usable electricity, three or more of these cells are used in series to create a single lithium-ion battery.

Lithium Iron Phosphate Batteries

As technology progressed, new materials were tried as cathode materials in the lithium-ion battery. One of these materials is Lithium Iron Phosphate (LiFe.

The batteries that utilise Lithium Iron Phosphate as the cathode material are called Lithium Iron Phosphate batteries (LiFePO4 or LFP batteries).

A single cell of a lithium iron battery creates a voltage between 3.2V to 3.3 V. Therefore, three or four of these cells are connected in series to create a single LFP battery.

What are the similarities between Lithium-ion batteries and LFP batteries?

As mentioned earlier, both lithium-ion batteries and LFP batteries fall under the class of lithium-based batteries. Therefore, there are a lot of similarities between the two types.

For one thing, both of these batteries rely on the movement of lithium ions to generate current. Additionally, both of these use graphite as the anode material.

There are fewer differences between lithium-ion batteries and LFP batteries than any instance where you compare any of these batteries with any battery that doesn’t use lithium.

How Do Lithium Iron Phosphate Batteries and Lithium-ion Batteries Compare?

How Do Lithium Iron Phosphate Batteries and Lithium-ion Batteries Compare

We will go through the comparison between an LFP battery and other lithium ion batteries based on the various factors that are important.

Energy Density

The energy density is the amount of electricity a battery can provide in relation to the mass of the battery. It is measured in Watt-hours per Kg (Wh/kg). If a battery has a higher energy density, a smaller mass of that battery can provide more electricity.

Lithium Ion

Lithium ion batteries have one of the highest energy density among any battery types. These batteries provide an energy density of about 100 Wh/kg to 265 Wh/kg.

LiFePO4

The energy density of an LFP battery is slightly lower than a lithium-ion battery. Their energy density falls between 90-165 Wh/kg.

Verdict: Lithium-ion batteries have a higher energy density. This is why these batteries find applications in smaller-sized, power-hungry requirements.

Cycle Life and Lifespan

Cycle life refers to the number of cycles that a battery can sustain without any drop in performance. One cycle is the process of going from one full charge to one full discharge, and then fully charging again.

A longer cycle life indicates that a battery is going to last longer, providing you with a better value for money on your investment.

Lithium ion

Lithium-ion batteries usually provide a cycle life between 300 to 500 cycles. This roughly translates to a time period of about two to three years.

LiFePO4

LFP batteries have a substantial cycle life of about 3000 cycles. This translates to a time period of above seven years.

Verdict: LFP batteries are leaps and bounds ahead in terms of cycle life and battery lifespan, lasting about four to five times longer than lithium-ion batteries.

Depth of Discharge (DoD)

Depth of Discharge (DoD)

Depth of Discharge refers to the percentage till which a battery can be discharged without causing any harm to the battery. If a battery gets discharged beyond the depth of discharge, it can permanently damage the battery.

A higher depth of discharge indicates a wider performance range for the battery, since you are utilising more of the stored energy.

Lithium ion

Lithium ion batteries have a depth of discharge of between 80% to 95%. This means that you have to leave behind at least 5% to 20% charge (exact number depending on the particular battery) in the battery at any time.

LiFePO4

Lithium Iron Phosphate batteries have an astonishing depth of discharge of an astonishing 100%. This means that you can fully drain the battery without any worry of damaging it.

Verdict: The Lithium Iron Phosphate battery is the clear winner when it comes to depth of discharge. As an interesting fact, all lithium-based batteries have considerably higher DoD than lead-acid batteries, as the latter only offers a DoD of 50%.

Self Discharge Rate

Even when a battery is not connected to any appliance, there are internal chemical reactions happening that drain some stored charge, even if it is negligible. The self-discharge rate is the rate at which the battery loses its charge when it is not in a connected state.

Lower self-discharge rates is better for the battery, as it indicates better chemical stability and longer charge retention.

Lithium-ion

For a lithium-ion battery, the self-discharge rate is about 5% per month. This means that if a lithium-ion battery is charged, disconnected and stored, it will go from 100% to 95% after 1 month of storage.

LiFePO4

For lithium iron phosphate, the self-discharge rate is about 3% per month. This means that after 1 month of storage, the battery will go from 100% to 97%.

Verdict: Lithium iron phosphate batteries have a slightly better performance when we talk about the self-discharge rate. Again, both these batteries perform remarkably better than lead-acid batteries, which have a terrible self-discharging of about 4% per week.

Cost per KWh

Cost per KWh

The cost per KWh is the amount of money you spend for every KWh of battery capacity. Since every type of battery is available in a variety of storage sizes, comparing them on the basis of Cost per KWh is the better option for finding cost-effectiveness.

To calculate cost per KWh, you first need to calculate the KWh rating of the battery. This value is not always listed on the battery, but it can be easily calculated.

KWh= (Voltage x Ampere Hours)/1000

Both voltage and ampere hours are always listed on the battery you buy.

Lithium-ion

A lithium ion battery uses cobalt as an electrode material, which leads to higher cost of the battery.

LiFePO4

Lithium Iron Phosphate battery uses cobalt-free options like iron and phosphate, both of which are way cheaper.

Verdict: Lithium iron phosphate battery is slightly cheaper than its lithium-ion counterpart.

Weight

Weight can be a crucial factor for applications like electric motors, where weight can affect performance.

Lithium-ion

Lithium ion batteries contain compounds of lithium manganese oxide and lithium cobalt oxide, both high density materials that weigh more.

LiFePO4

Lithium iron phosphate contains compounds of iron, which is considerably lighter than the metals used in a Lithium-ion battery.

Verdict: Lithium iron batteries weigh less than a lithium-ion battery of the same capacity, with a difference of about 50% on average.

Applications

When deciding on the battery type, it is important to ascertain if the particular type would be suitable for your required applications. Here is an application comparison of these two types of batteries:

Lithium-ion

Due to the higher energy density, lithium-ion is more suitable for applications that have limitations on the battery size. The most prominent of these applications are electronic devices such as electronic cigarettes, phones, and other small rechargeable devices.

LiFePO4

Due to their numerous advantages and better performance, lithium iron phosphate batteries have extensive applications in electric vehicles, recreational vehicles, solar batteries, and more.

Verdict: The applications of both these batteries are quite different, so each one is the winner in its own domain. When there is a serious size limitation, lithium-ion performs better and when high performance is required, lithium iron batteries perform better.

Cold Weather Usage

Cold Weather Usage

When the weather drops below freezing point, the operational capability of most batteries decreases, and many stop functioning completely. Lithium batteries are very prone to freezing temperature and don’t work below a certain temperature point.

Lithium-ion

If you have been in an extremely cold region, you will notice that your smartphone stops working in extreme cold, due to the battery shutting down. All lithium-ion batteries are prone to cold weather in the same way.

LiFePO4

Lithium iron phosphate also ceases to operate at very low temperatures. However, high-quality lithium iron phosphate batteries, such as those offered by Ecotreelithium, come with a battery management system (BMS) that can heat the battery automatically at cold temperatures.

Verdict: The BMS features of a lithium iron battery tips the scale in its favour during the cold weather operation of the battery.

Thermal Stability

The thermal stability refers to the temperature related parameters such as overheating of the battery and thermal runaway. Thermal runaway is a serious concern that denotes the uncontrolled overheating of a battery, which can even cause it to explode.

Lithium-ion

Lithium-ion are notorious for their temperature behaviour as they get overheated very commonly. There have been instances of lithium manganese oxide batteries exploding in laptops. Thermal runaway is common in these batteries.

LiFePO4

First of all, LiFePO4 batteries are 100% incombustible, so there is no chance of a lithium iron battery catching fire or exploding. There is no overheat in these batteries regardless of how you charge them. Additionally, there is zero thermal runaway.

Verdict: When you compare the thermal stability of LiFePO4 vs lithium-ion, lithium iron batteries are the major winner.

Environmental Concerns

Environmental Concerns

Manufacturing companies and users are driving towards environmentally safe products and processes. As such, it is important to find out which battery is more environmentally friendly.

Lithium-ion

Lithium-ion batteries are found to release a large number of toxic gases, especially at high temperatures. These batteries have a shorter life span, so you have to change them often leading to high wastes.

LiFePO4

Lithium iron batteries have no environmental concerns since they do not release any type of toxic gases or chemicals. Additionally, these batteries have a long life span, leading to few battery changes.

Verdict: Lithium iron phosphate is one of the most environmentally-friendly batteries out there.

Warranty

A longer warranty period guarantees a better return on investment since you are assured that the battery will work for at least the warranty period.

Lithium-ion

Since the entire lifespan of a lithium-ion battery is about two years, you can expect a warranty of six months to one year. For instance, you can see the common six-month warranty that you get on the batteries in smartphones.

LiFePO4

Lithium iron phosphate typically comes with a warranty period of 5 years. The highest quality LFP batteries, such as those provided by Ecotreelithium, come with a warranty of 6 years!

Verdict: Lithium iron phosphate batteries don’t just sound good on paper, there is a longer warranty period to provide it. They are definitely far ahead of their lithium-ion counterparts when you compare six months vs the six-year warranty period.

LiFePO4 vs Lithium-ion: Which One to Choose?

LiFePO4 vs Lithium-ion: Which One to Choose

While both of these are lithium batteries, there are significant differences in performance between the two.

LiFePO4 is the better choice in all factors that matter. With these batteries, you get better performance, better value for money, and a considerably longer lifespan.

The only factor where the lithium-ion counterpart shines brighter is when you consider the energy density. This makes them the better choice for electronic applications such as smartphones, laptops, electronic cigarettes, and any other electronic appliances.

Besides the electronics, LiFePO4 batteries are better suited for every other application. Whether it is electric vehicles, solar panels, caravans, motorhomes, or any high capacity requirement, LiFePO4 is the best investment.

Are Lithium Batteries Better Than the Non-Lithium Alternatives?

Are Lithium Batteries Better Than the Non-Lithium Alternatives

The debate between lithium iron phosphate batteries and lithium-ion batteries clearly favours the former. However, when you compare any of these two types with non-lithium batteries, lithium cells win by a huge margin.

Lead Acid Batteries

Lead-acid batteries gained huge popularity as automotive starter batteries and UPS batteries. However, lithium batteries are taking over their market share day by day.

While lead-acid batteries are cheaper, lithium batteries can last ten times longer. Additionally, lead-acid batteries require constant maintenance such as electrolyte top-up and terminal maintenance. These things are not a requirement in lithium batteries.

For an in-depth comparison between the two types, you can read our guide on lead acid vs lithium batteries.

Gel Batteries

Gel batteries were developed as an improvement on the lead acid batteries, with a sealed construction that doesn’t require electrolyte top up.

However, when you compare these to lithium batteries, they still lag far behind. Firstly, a lithium battery lasts longer than gel batteries. Additionally, gel batteries require special provisions like venting in the battery compartment, which are not a requirement for a lithium battery.

There are many advantages of lithium battery when compared to gel battery. We have a detailed article about lithium vs gel batteries for detailed knowledge.

AGM Batteries

AGM batteries are one of the newest battery types and have become widely adopted in place of lead batteries and gel batteries.

However, the performance of these batteries also feels pale when you put them besides a lithium battery.

Lithium based batteries, especially LiFePO4 batteries, can last six times longer and offer a higher depth of discharge.

While lead acid battery had the advantage of being enormously cheaper, AGM batteries are expensive. Therefore, it is better to choose LiFePO4 batteries over AGM regardless of the application you consider.

Our guide on AGM vs Lithium batteries will give you a better idea of the differences between these two batteries.

Endnotes

Lithium batteries are by far the best types of batteries that one can find today. Within the lithium battery class, people have been often confused between commonly available types such as lithium-ion and lithium iron phosphate batteries.

With the help of the extensive information provided here, you can make the decision between LiFePO4 vs lithium-ion batteries very easily.

If you are in the market for a new battery, we recommend checking Ecotreelithium’s range of LiFePO4 batteries. These not only come with a six year warranty, but are also equipped with many other features that you won’t find anywhere else.

For instance, you get a battery management system that constantly regulates the charging and temperature for optimising the battery life. Not to forget, there is a six-year warranty on the battery itself. What else can one ask for!

Frequently Asked Questions (FAQs)

Here are the answers to some commonly asked questions about lithium batteries.

Is LiFePO4 better than Lithium-ion?

Yes, a Lithium iron phosphate battery is quite better than lithium-ion and a better value for money. However, for small electronic devices like smartphones, lithium-ion is the better choice.

Can you charge LiFePO4 battery with Lithium-ion battery charger?

Yes, it is possible to charge a LiFePO4 battery with a lithium-ion charger or even an AGM charger. The important thing to ensure is that the charger should have the exact voltage rating as required by the LiFePO4 battery. A lower voltage charger won’t charge the battery to 100%.