Table of Contents
- LiFePO4 vs. Ternary Li: Best Battery Choice?
LiFePO4 vs. Ternary Li: Best Battery Choice?
We have been hearing a lot about lithium iron phosphate batteries lately, and to some extent, they correspond to ternary lithium batteries, which are currently the two most mainstream battery types. Ternary lithium batteries work well, so why use two different types of batteries in the same car? What is the difference between lithium iron phosphate batteries and ternary lithium batteries for us?
1. Comparing LiFePO4 and. Ternary Li Batteries
In fact, it’s not just the Xpeng P7; a more well-known example is the Tesla Model 3, which also uses lithium iron phosphate batteries in its standard range version. The main reason for this is, of course, cost considerations, which enable the entry-level version of the Model 3 to be priced even lower.
Due to their low material cost and stable, safe structure, many early electric vehicles used lithium iron phosphate batteries, which is one of their biggest advantages. However, with the development of the electric vehicle industry, battery technology has been greatly influenced by industry subsidy policies, with the core factors being pure electric range and battery energy density. As a result, more and more electric vehicles have started to adopt ternary lithium batteries with higher energy density.
Here, the names of the two batteries actually refer to the positive electrode materials of their battery cells. Lithium iron phosphate batteries naturally use lithium iron phosphate (LiFePO4), while the ternary materials in ternary lithium batteries refer to the combination of nickel (Ni), cobalt (Co), manganese (Mn), or aluminum (Al) (commonly known as NCM or NCA), with different proportions of the three (e.g., “523”, “811”) set according to the needs of the vehicle, giving the battery different focuses.
To be more specific, nickel in ternary lithium batteries can increase the reversible capacity of the material and improve the energy density of the battery, which is mainly responsible for increasing battery capacity and vehicle range. Cobalt can enhance lithium-ion deintercalation, increasing the charging and discharging speed of the battery and thus improving charging efficiency. The role of manganese or aluminum is mainly to enhance the safety and stability of the battery. Therefore, the combination of the three materials can significantly increase battery energy density, allowing the same volume of battery to have a higher capacity, making it more favored under policy support.
But at the same time, the relatively reactive chemical properties of nickel make ternary lithium batteries unable to withstand high temperatures, and the binding of oxygen elements is relatively low. As a result, we have seen a number of cases where electric vehicles using ternary lithium batteries caught fire and burned spontaneously, causing many people to worry about the safety of electric vehicles.
On this point, lithium iron phosphate batteries, due to their stable internal structure, are less prone to decomposition at higher temperatures. They not only have a strong resistance to high temperatures and overcharging but can also better cope with collisions, short circuits, and other situations, with a relatively lower probability of spontaneous combustion. However, their weakness lies in low-temperature environments, where the relatively stable structure further reduces the diffusion speed of lithium ions, resulting in a significant impact on the electrochemical activity of the battery in cold weather. This leads to a substantial decrease in range during winter, as we have seen in the news about Tesla owners seeking compensation.
2. Distinct Applications of LiFePO4 and. Ternary Li Batteries
So, after getting a general understanding of lithium iron phosphate batteries and ternary lithium batteries, we can find that both types of batteries have their pros and cons, as well as different application scenarios. Let’s first briefly summarize them.
Summarize lithium iron phosphate and ternary lithium batteries:
|LiFePO4 Battery||Lower Price; Safe & Reliable; Long life of charge and discharge cycle||The upper limit of energy density is low; The low temperature performance is poor|
|Ternary lithium battery||Good low temperature performance; High energy density; High charging and discharging efficiency||High cost; High temperature resistance is relatively poor|
Looking at it from another perspective, let’s compare the current advantages and disadvantages of both types based on the main indicators.
Compare lithium iron phosphate batteries and ternary lithium batteries:
|Energy density||Temperature characteristic||Cost||Lifesoan||Safe|
|LiFePO4 Battery||Low||Poor Performance of low temperature||Low||Long||bettery|
|Ternary lithium battery||High||High temperature decomposition||High||Ordinary||Ordinary|
In short, lithium iron phosphate batteries are more suitable for car models that have high safety requirements, certain cost constraints, but do not mind the battery volume, such as relatively more affordable entry-level electric vehicles, high-mileage operational vehicles, or larger commercial vehicles. Just like the Xpeng P7 rear-wheel-drive standard range version and the Tesla Model 3 standard range version, they chose lithium iron phosphate batteries for their entry-level models, further reducing the price, and making them more attractive to consumers in warmer southern regions or those with sufficient charging conditions.
For high-end models that focus more on experience and comfort, ternary lithium batteries may be a better choice, as their higher range, more spacious interior, and faster charging efficiency can significantly enhance the driving experience. For example, mainstream electric vehicles using ternary lithium batteries have a range of about 500km, which is sufficient for commuting in first-tier cities. Charging for an hour every one or two weeks can basically meet the vehicle’s needs.
At present, both types of batteries have seen effective improvements to their weaknesses in terms of technology, such as optimizing battery manufacturing processes, battery management systems, and increasing heat pumps to improve thermal management efficiency. For example, BYD’s blade battery has significantly increased its cell capacity and volume utilization through structural innovation, with a claimed range comparable to that of ternary lithium batteries. At the same time, ternary lithium batteries are also improving stability and safety by using different packaging forms and protective measures for their casings.
Therefore, at this stage, both lithium iron phosphate batteries and ternary lithium batteries have seen significant improvements through technology upgrades and iterations in recent years. Which is better depends more on the needs of car manufacturers and consumers – the best choice is the one that suits you. Moreover, although the differences in characteristics between the two still exist, they can cover a wider range of use scenarios compared to the past, just like the different battery versions of Xpeng P7 and G3, both of which can serve the same target customer group.
In conclusion, lithium iron phosphate batteries and ternary lithium batteries are not an iterative relationship, as some people understand, but rather have different characteristics and emphases. However, considering the increasing demands of consumers and the development process of electric vehicles, high range and fast charging are two indispensable requirements, and ternary lithium batteries may be more in line with the trend of the times.
But the ultimate goal of batteries is not limited to lithium iron phosphate batteries and ternary lithium batteries. We are all waiting for substantial breakthroughs in battery cell technology, such as the intensively deployed solid-state batteries, graphene batteries seen as a gimmick, and perhaps not-too-distant lithium-air batteries, among others. In the future, we will undoubtedly see higher forms of batteries emerge.