A Comparison of the Pros and Cons of LiFePO4 Batteries, Ternary Lithium Batteries, and Lead-Acid Batteries
Advantages of LiFePO4 Batteries
LiFePO4 batteries are lithium-ion batteries that use lithium iron phosphate as the cathode and graphite as the anode, with a single-cell voltage of 3.2V and a charge cut-off voltage of approximately 3.6~3.65V.
- High energy density: The energy density of LiFePO4 batteries is 140~250Wh/kg, much higher than the 30~50Wh/kg of lead-acid batteries.
- Fast charging: For branded LiFePO4 batteries, they can be fully charged in about 1 hour normally. With fast charging, it only takes 20~30 minutes to charge from 15% to 80%, making them the fastest-charging batteries currently available.
- Small size and light weight: LiFePO4 batteries of the same capacity are only 30% the weight of lead-acid batteries, with obvious advantages in size and weight.
- High safety: The thermal runaway temperature of LiFePO4 batteries is usually 500~800°C, with good thermal stability. With advances in manufacturing technology, modern LiFePO4 cells only emit smoke without catching fire even when subjected to puncturing, crushing, or short circuits, making them far safer than ternary lithium batteries.
- Long service life: Most LiFePO4 batteries on the market have 2000~3000 charge-discharge cycles. For example, BYD’s LiFePO4 batteries for two/three-wheeled EVs support up to 3300 cycles. Charging once every two days, they can last up to 10 years.
- More eco-friendly: LiFePO4 batteries contain no toxic heavy metals, are easier to produce and recycle, and have less environmental impact.
Disadvantages of LiFePO4 Batteries
- Poor low-temperature performance: Without a heating function, LiFePO4 batteries lose about 30% capacity at 0°C and over 50% at -10°C, performing worse than ternary lithium batteries in cold conditions. However, BYD’s LiFePO4 batteries feature an automatic heating system that can warm the battery to 25°C within minutes using only 5% power, minimizing capacity loss in winter.
- Poor consistency: There are large deviations in capacity, voltage, and current between individual LiFePO4 cells, which worsen over time. This can be mitigated by fully discharging the battery once a month and then recharging it continuously without interruption to minimize parameter differences and improve overall battery performance.
Ternary Lithium Batteries
Ternary lithium batteries are lithium-ion batteries using nickel, cobalt, and manganese as cathode materials, with a nominal voltage of 3.6~3.7V. Due to the use of rare precious metals, they have high production costs and selling prices.
Advantages
- Ultra-high energy density: Ternary lithium batteries have an energy density of 200~250Wh/kg, the highest among current batteries.
- Light weight: A typical 48V20Ah lead-acid battery weighs 28kg, while a ternary lithium battery of the same capacity is only 1/3 the weight.
- High discharge power: They support high-power discharge, enabling fast startup and strong acceleration for electric vehicles, making them suitable for high-performance motors.
- Fast charging: Supporting high-rate charging, they can be fully charged in 2~4 hours with standard fast charging, or 30 minutes to 1 hour with super fast charging. However, overly fast charging increases heat generation, accelerating aging and shortening lifespan.
- Long service life: They support 1000~2000 charge-discharge cycles, with a service life of 5~8 years.
Disadvantages
- High cost: Cathode materials are rare and mostly imported, leading to high raw material and retail prices—usually 2.5~3 times that of ordinary lead-acid batteries.
- Poor safety: The thermal runaway temperature is only 250°C. Most electric vehicle fires are caused by thermal runaway of ternary lithium batteries, triggered by overcharging, over-discharging, water ingress, physical impact, or BMS failure.
- High recycling requirements: Recycling and refining ternary lithium batteries is complex and costly.
Lead-Acid Batteries
Invented by French scientist Gaston Planté in 1859, lead-acid batteries typically contain 6 cells, each with a nominal voltage of 2V, chargeable up to 2.4V and dischargeable down to 1.5V. Six cells connected in series form a 12V battery. Common capacities include 12Ah, 20Ah, 23Ah, 32Ah, 38Ah, 45Ah, 58Ah, etc.
Four in series make a 48V pack, five make 60V, and six make 72V. Graphene batteries on the market are upgraded lead-acid batteries with graphite-rich materials added to improve energy density, charging speed, and low-temperature performance.
Advantages
- Mature technology: After over 100 years of development, lead-acid batteries have stable raw materials, proven processes, and low manufacturing barriers. Both major brands and local manufacturers can produce reliable products.
- Low cost: They are the cheapest type of battery due to mature technology, abundant low-cost raw materials, and a complete industrial chain.
- High residual value & cost-effective trade-ins: Used lead-acid batteries have high recycling value. For example, a scrap 12V20Ah cell can be recycled for about 50 yuan, as lead plates can be refined and reused. Trade-ins are common: a new 48V20Ah set costs around 500 yuan, with a 200-yuan credit for the old battery, so only 300 yuan extra is paid.
- Good safety and easy maintenance: Stable chemical properties prevent combustion or explosion. Most are maintenance-free, requiring little upkeep with proper charging and use.
Disadvantages
- Low energy density: Ordinary lead-acid batteries have 30~40Wh/kg; upgraded graphene versions reach 40~50Wh/kg, the lowest among all batteries.
- Heavy weight: A 12V20Ah lead-acid cell weighs about 7kg, while lithium batteries of the same capacity are only 1/2~1/3 the weight.
- Short lifespan: Ordinary lead-acid batteries support about 350 cycles, lasting around 2 years. Graphene versions reach 600~1000 cycles for 3~4 years, still the shortest lifespan.
- Slow charging: It takes 6~8 hours to fully charge from 30% remaining power, the slowest among all battery types.
- High self-discharge rate: Monthly self-discharge is 20%~30%, increasing exponentially as power drops. An electric vehicle left unused for two months may suffer irreversible capacity loss or fail to charge entirely.
- Environmental pollution: Lead is a toxic heavy metal, and sulfuric acid also pollutes the environment. Improper disposal contaminates water and soil, endangering human health.
Which Is Better: Lead-Acid, Ternary Lithium, or LiFePO4 Batteries?
- Lead-acid batteries: Cheap, recyclable, and safe, but short-lived, poor in low temperatures, slow-charging, bulky, and heavy, raising long-term costs from frequent replacements.
- Ternary lithium batteries: Light, high-energy-density, and fast-charging, but less safe.
- LiFePO4 batteries: Excellent overall performance—fast charging, moderate energy density, high safety, long lifespan, and fast-charging compatible.
In summary, LiFePO4 batteries offer the best overall performance.