In terms of cycle life and economy, lifepo4 batteries’ cycle life is as much as 5,000 times (at 80% depth of discharge), more than ten times that of lead-acid batteries (300-500 times). Calculated based upon one charge and discharge per day, their service life can reach as much as 13.7 years (lead-acid batteries only last 1.5 years). Let’s take the example of a 10 kWh energy storage system. The lifepo4 cost of electricity per kilowatt-hour (LCOE) is 0.03 US dollars /kWh, while that of lead-acid batteries is 0.25 US dollars /kWh, increasing the long-term return on investment by 733%. For instance, after the launch of lifepo4 technology by Tesla Powerwall, the yearly maintenance cost of the average user dropped from $200 for lead-acid batteries to $15, and the battery is not changed during the course of the 10-year warranty (lead-acid batteries are changed six times).
In volume efficiency and energy density, lifepo4 has an energy density of 200 Wh/kg (lead-acid batteries’ is only 50 Wh/kg), and its weight is reduced by 60%. Take the RV energy storage case as an example. A 10 kWh lifepo4 battery set weighs 55 kg, while a lead-acid battery requires 220 kg. The remaining load space is available for the luggage of up to 4 people (circa 165 kg). The 2023 U.S. Department of Energy report shows that lifepo4’s modular design allows for parallel expansion to 40 kWh (to 10 kWh for lead-acid batteries), adapting to off-grid systems’ load requirements (e.g., simultaneous powering of 2 kW air conditioning and 1 kW lighting).
In performance of charging and discharging, lifepo4 accepts 1C rate quick charging (fully charged within 1 hour with 10 kW power), with efficiency of 95% (80% for lead-acid batteries, takes 8 hours). For instance, one off-grid solar user recorded that, after switching to lifepo4, the average daily rate of power generation waste reduced from 18% in the lead-acid solution to 3%, and discharge efficiency was still maintained at 90% under the low temperature of -20°C (lead-acid batteries degraded to 40% at 0°C). According to NREL tests, its voltage range during full charge and discharge cycles is only ±1% (±5% for lead-acid batteries), which adds 23% to the life of the inverter.
In terms of environmental protection and safety, lifepo4 has also passed UL 1973 certification. It has a risk of thermal runaway of less than 0.001% (the risk of acid leakage in lead-acid batteries is 0.1%), and it contains no heavy metal lead (lead-acid batteries contain 60% lead). In the 2021 California wildfires, a certain microgrid used lifepo4 battery packs to operate for 72 hours continuously at 45°C without failure, but lead-acid batteries suffered irreversible 30% capacity loss due to sulfation. In addition, the recycling rate of lifepo4 can reach 98% (80% for lead-acid batteries), and the carbon footprint during the production process is 70% lower than that of lead-acid batteries.
Market trends indicate that lifepo4 is rapidly replacing lead-acid batteries. In the 2023 global energy storage market, the penetration rate of lifepo4 jumped from 12% in 2019 to 58%, and the user satisfaction rate was 94% (62% for lead-acid batteries). For instance, after a certain German car manufacturer switched to lifepo4 as the onboard backup power supply, the battery failure rate dropped from 1.2 times per thousand hours to 0.1 times, and the claim cost under the warranty was cut by 85%. Policy-oriented, the European Union will ban lead-acid batteries in 2030, further powering lifepo4 to the mainstream.