Different types of lithium batteries rely on unique active materials and chemical reactions to store energy. Each type of lithium battery has its benefits and drawbacks, along with its best-suited applications.
The different lithium battery types get their names from their active materials. For example, the first type we will look at is the lithium iron phosphate battery, also known as LiFePO4, based on the chemical symbols for the active materials. However, many people shorten the name further to simply LFP.
Lithium Iron Phosphate
Lithium iron phosphate (LFP) batteries use phosphate as the cathode material and a graphitic carbon electrode as the anode. LFP batteries have a long life cycle with good thermal stability and electrochemical performance.
What Are They Used For:
LFP battery cells have a nominal voltage of 3.2 volts, so connecting four of them in series results in a 12.8-volt battery. This makes LFP batteries the most common type of lithium battery for replacing lead-acid deep-cycle batteries.
There are quite a few benefits to lithium iron phosphate batteries that make them one of the most popular options for applications requiring a large amount of power. The primary benefits, however, are durability, a long life cycle, and safety.
LFP batteries typically have a lifecycle rating of 2,000 cycles or more. Unlike lead-acid batteries, depth of discharge has a minimal impact on the lifespan of LFP batteries. Most LFP manufacturers rate their batteries at 80% depth of discharge, and some even allow 100% discharging without damaging the battery.
The materials used in lithium iron phosphate batteries offer low resistance, making them inherently safe and highly stable. The thermal runaway threshold is about 518 degrees Fahrenheit, making LFP batteries one of the safest lithium battery options, even when fully charged.
There are a few drawbacks to LFP batteries. The first is that compared to other lithium battery types, they have a relatively low specific energy. Their performance can also suffer in low temperatures. Combining the low specific energy and reduced performance in cold temperatures means LFP batteries may not be a great fit in some high cranking applications.
Lithium Cobalt Oxide
Lithium cobalt oxide (LCO) batteries have high specific energy but low specific power. This means that they do not perform well in high-load applications, but they can deliver power over a long period.
What Are They Used For:
LCO batteries were common in small portable electronics such as mobile phones, tablets, laptops, and cameras. However, they are losing popularity to other types of lithium batteries due to the high cost of cobalt and concerns around safety.
The key benefit to LCO batteries is their high specific energy. This allows them to deliver power over a relatively long period under low-load applications.
LCO batteries have some significant drawbacks resulting in them becoming less popular in recent years. First, LCO batteries suffer from a relatively short lifespan, usually between 500-1,000 cycles. Additionally, cobalt is fairly expensive. Expensive batteries that don’t last a long time are not cost-effective.
LCO batteries also have low thermal stability, which leads to safety concerns. Furthermore, their low specific power limits the ability of LCO batteries to perform in high-load applications.