What Is LiFePO4 And Why Is It A Better Choice?

What Is LiFePO4 And Why Is It A Better Choice?

  All lithium chemistries are not created equal. In fact, most American consumers – electronic enthusiasts aside – are only familiar with a limited range of lithium solutions. The most common versions are built from cobalt oxide, manganese oxide and nickel oxide formulations.


   



    First, let’s take a step back in time. Lithium-ion batteries are a much newer innovation and have only been around for the last 25 years. Over this time, lithium technologies have increased in popularity as they have proven to be valuable in powering smaller electronics – like laptops and cell phones. But as you may recall from several news stories over recent years, lithium-ion batteries also gained a reputation for catching fire. Until recent years, this was one of the main reasons lithium wasn't commonly used to create large battery banks.


   



    But then came along lithium iron phosphate (LiFePO4). This newer type of lithium solution was inherently non-combustible, while allowing for slightly lower energy density. LiFePO4 batteries were not only safer, they had many advantages over other lithium chemistries, particularly for high power applications.


   



    Although lithium iron phosphate (LiFePO4) batteries aren’t exactly new, they’re just now picking up traction in Global commercial markets. Here’s a quick breakdown on what distinguishes LiFePO4 from the other lithium battery solutions:


   



    Safety And Stability


    LiFePO4 batteries are best known for their strong safety profile, the result of extremely stable chemistry. Phosphate-based batteries offer superior thermal and chemical stability which provides an increase in safety over lithium-ion batteries made with other cathode materials. Lithium phosphate cells are incombustible, which is an important feature in the event of mishandling during charging or discharging. They can also withstand harsh conditions, be it freezing cold, scorching heat or rough terrain.


   



    When subjected to hazardous events, such as collision or short-circuiting, they won’t explode or catch fire, significantly reducing any chance of harm. If you’re selecting a lithium battery and anticipate use in hazardous or unstable environments, LiFePO4 is likely your best choice.


   



    Performance


    Performance is a major factor in determining which type of battery to use in a given application. Long life, slow self-discharge rates and less weight make lithium iron batteries an appealing option as they are expected to have a longer shelf life than lithium-ion. Service life usually clocks in at five to ten years or longer, and runtime significantly exceeds lead-acid batteries and other lithium formulations. Battery charging time is also considerably reduced, another convenient performance perk. So, if you’re looking for a battery to stand the test of time and charge quickly, LiFePO4 is the answer.


   



    Space Efficiency


    Also worth mentioning is LiFePO4’s space-efficient characteristics. At one-third the weight of most lead-acid batteries and almost half the weight of the popular manganese oxide, LiFePO4 provides an effective way to make use of space and weight. Making your product more efficient overall.  


   



    Environmental Impact


    LiFePO4 batteries are non-toxic, non-contaminating and contain no rare earth metals, making them an environmentally conscious choice. Lead-acid and nickel oxide lithium high rate batteries carry significant environmental risk (especially lead acid, as internal chemicals degrade structure over team and eventually cause leakage). There is also VRLA battery.


   



    Compared to lead-acid and other lithium batteries, lithium iron phosphate batteries offer significant advantages, including improved discharge and charge efficiency, longer life span and the ability to deep cycle while maintaining performance. LiFePO4 batteries often come with a higher price tag, but a much better cost over life of the product, minimal maintenance and infrequent replacement makes them a worthwhile investment and a smart long-term solution.


   



    A lithium-ion (Li-ion) battery is an advanced battery technology that uses lithium ions as a key component of its electrochemistry. During a discharge cycle, lithium atoms in the anode are ionized and separated from their electrons. The lithium ions move from the anode and pass through the electrolyte until they reach the cathode, where they recombine with their electrons and electrically neutralize. The lithium ions are small enough to be able to move through a micro-permeable separator between the anode and cathode. In part because of lithium’s small size (third only to hydrogen and helium), Li-ion batteries are capable of having a very high voltage and charge storage per unit mass and unit volume.


   



    Li-ion batteries can use a number of different materials as electrodes. The most common combination is that of lithium cobalt oxide (cathode) and graphite (anode), which is most commonly found in portable electronic devices such as cellphones and laptops. Other cathode materials include lithium manganese oxide (used in hybrid electric and electric automobiles) and lithium iron phosphate. Li-ion batteries typically use ether (a class of organic compounds) as an electrolyte.


   



    What are some advantages of Li-ion batteries?


    Compared to the other high-quality rechargeable battery technologies (nickel-cadmium or nickel-metal-hydride), Li-ion batteries have a number of advantages. They have one of the highest energy densities of any battery technology today (100-265 Wh/kg or 250-670 Wh/L). In addition, Li-ion battery cells, including a 3.2V Lithium Battery Cell, can deliver up to 3.6 Volts, 3 times higher than technologies such as Ni-Cd or Ni-MH. This means that they can deliver large amounts of current for high-power applications, which has Li-ion batteries are also comparatively low maintenance, and do not require scheduled cycling to maintain their battery life. Li-ion batteries have no memory effect, a detrimental process where repeated partial discharge/charge cycles can cause a battery to ‘remember’ a lower capacity. This is an advantage over both Ni-Cd and Ni-MH, which display this effect. Li-ion batteries also have low self-discharge rate of around 1.5-2% per month. They do not contain toxic cadmium, which makes them easier to dispose of than Ni-Cd batteries.


   



    Due to these advantages, Li-ion deep cycle batteries have displaced Ni-Cd batteries as the market leader in portable electronic devices (such as smartphones and laptops). Li-ion batteries, like a 12V lithium battery, are also used to power electrical systems for some aerospace applications, notable in the new and more environmentally friendly Boeing 787, where weight is a significant cost factor. From a clean energy perspective, much of the promise of Li-ion technology comes from their potential applications in battery-powered cars. Currently, the bestselling electric cars, the Nissan Leaf and the Tesla Model S, both use Li-ion batteries as their primary fuel source.


   



    What are some disadvantages of Li-ion batteries?


    Despite their technological promise, Li-ion batteries still have a number of shortcomings, particularly with regards to safety. Li-ion batteries have a tendency to overheat, and can be damaged at high voltages. In some cases this can lead to thermal runaway and combustion. This has caused significant problems, notably the grounding of the Boeing 787 fleet after onboard battery fires were reported. Because of the risks associated with these batteries, a number of shipping companies refuse to perform bulk shipments of batteries by plane. Li-ion batteries require safety mechanisms to limit voltage and internal pressures, which can increase weight and limit performance in some cases. Li-ion gel batteries are also subject to aging, meaning that they can lose capacity and frequently fail after a number of years. Another factor limiting their widespread adoption is their cost, which is around 40% higher than Ni-Cd. Addressing these issues is a key component for current research into the technology. Finally, despite the high energy density of Li-ion compared to other kinds of batteries, they are still around a hundred times less energy dense than gasoline (which contains 12,700 Wh/kg by mass or 8760 Wh/L by volume).