When choosing between Lithium Iron Phosphate (LiFePO4) batteries and Ternary lithium batteries, several factors must be considered, including safety, cost, cycle life, energy density, and charging efficiency. Below is a detailed comparison of these two types of batteries:
1. Batteries Safety
Lithium Iron Phosphate (LiFePO4) Batteries
The cathode material of LiFePO4 batteries is lithium iron phosphate, which has excellent thermal and chemical stability. LiFePO4 has a fire ignition point of around 500°C, making it less prone to thermal runaway even under high temperatures or overcharging, thus ensuring a higher level of safety.
Puncture tests show that LiFePO4 batteries do not ignite during puncture, a result of their electrochemical properties.
Ternary Lithium Batteries
Ternary lithium batteries use nickel-cobalt-manganese oxide (LiNiO2/LiMnO2/LiCoO2) as their cathode material, with the ratio of nickel, cobalt, and manganese adjustable according to requirements. These batteries have poorer thermal stability with an ignition point around 200°C, making them more susceptible to thermal runaway under high temperatures or overcharging, thus presenting lower safety levels.
2. Batteries Cost
Lithium Iron Phosphate (LiFePO4) Batteries
LiFePO4 batteries utilize cheaper raw materials that are abundant and have lower environmental impacts, leading to a generally lower overall cost for the batteries.
Ternary Lithium Batteries
Ternary lithium batteries incorporate metals like nickel, cobalt, and manganese, which are scarce and expensive, resulting in a higher overall cost for these batteries.
3. Batteries Cycle Life
Lithium Iron Phosphate (LiFePO4) Batteries
LiFePO4 batteries boast a long cycle life, typically exceeding 3,500 cycles, with some reaching over 6,000 cycles. This longevity is attributed to the stable structure of LiFePO4, which experiences minimal volume changes during charge and discharge cycles, preserving the material’s structure and performance over time.
Ternary Lithium Batteries
Ternary lithium batteries have a relatively shorter cycle life, generally reaching around 4,000 cycles. The ternary materials undergo significant structural changes during charge and discharge, adversely affecting the battery’s longevity.
4. Batteries Energy Density
Lithium Iron Phosphate (LiFePO4) Batteries
LiFePO4 batteries have a lower energy density, with a maximum cell energy density of up to 160Wh/kg. This limitation restricts their application in passenger vehicles, especially when high mileage is required.
Ternary Lithium Batteries
Ternary lithium batteries have a higher energy density, reaching up to 200Wh/kg. This high energy density gives ternary lithium batteries an advantage in passenger car applications, providing longer range capabilities.
5. Batteries Charging Efficiency
Lithium Iron Phosphate (LiFePO4) Batteries
When charging below 10°C, LiFePO4 batteries have a similar charging efficiency to ternary lithium batteries. However, above 10°C, especially at 20°C, LiFePO4 batteries have a constant current ratio of only 10.08%, which is significantly lower than the ternary lithium battery’s 52.75%.
Ternary Lithium Batteries
Ternary lithium batteries exhibit higher charging efficiency at elevated temperatures, achieving a constant current ratio of approximately 52.75%. This advantage makes them superior for rapid charging applications.
Batteries Application Scenarios
Electric Vehicles
Lithium Iron Phosphate (LiFePO4) Batteries
Due to their high safety and long cycle life, LiFePO4 batteries are widely used in electric vehicles where safety and cost control are priorities. For instance, BYD electric vehicles utilize LiFePO4 batteries and enhance battery pack energy density through innovative designs like blade batteries and CTP technology.
Ternary Lithium Batteries
With their higher energy density and better charging efficiency, ternary lithium batteries are more common in high-end electric vehicles that require longer range capabilities. For example, some Tesla models employ ternary lithium batteries.
Energy Storage Systems
Lithium Iron Phosphate (LiFePO4) Batteries
Thanks to their high safety and long cycle life, LiFePO4 batteries are preferred materials in energy storage systems. These systems require extensive charge and discharge cycles, making the characteristics of LiFePO4 particularly suitable for this application.
Ternary Lithium Batteries
Ternary lithium batteries are less commonly used in energy storage systems, primarily due to their shorter cycle life and lower safety levels.
Conclusion
Lithium Iron Phosphate (LiFePO4) Batteries: These batteries exhibit clear advantages in safety, cost, and cycle life, making them suitable for applications with high demands for safety and cost control, such as electric vehicles and energy storage systems.
Ternary Lithium Batteries: These batteries excel in energy density and charging efficiency, making them appropriate for high-end electric vehicles with significant requirements for range and fast charging.
In summary, the choice between these two types of batteries depends on specific application needs. If safety, cost, and cycle life are priorities, LiFePO4 batteries are the better choice; if energy density and charging efficiency are critical, ternary lithium batteries are more appropriate.