LiFePO4 (lithium iron phosphate) battery is a lithium-ion battery that uses lithium iron phosphate as the cathode material. Its olivine crystal structure (space group Pnma) has only 6.8% volume change during charging and discharging (20% for lithium cobalt oxide batteries), which confers to it very high structural stability. The battery’s nominal voltage is 3.2V, the energy density is 120-160Wh/kg (60-120Wh/kg for nickel-metal-hydride batteries), and the cycle life can be 2000-5000 times (capacity retention rate > 80%), which is much more than the 800-1500 upper limit of ternary lithium batteries. For instance, BYD’s actual test data in 2021 show that electric buses using LiFePO4 batteries have a battery capacity degradation rate of only 0.03% per cycle for an 8-year operational duration (at 200 kilometers of operation per day), and the cost of life cycle as a whole is 62% lower than lead-acid batteries (calculated at 0.15 yuan per kilowatt-hour per kilometer).
The thermal stability of LiFePO4 batteries is significantly better compared to other lithium battery systems. Its onset temperature of thermal runaway can be as high as 270℃ (150℃ for ternary lithium batteries), and the oxygen produced during decomposition is lowered by 90% (oxygen generation per unit mass < 0.16g/Ah), significantly reducing the fire risk. UL 1642 standard test of the United States shows that the highest surface temperature of this battery in needle-puncture test is only 82℃ (420℃ for ternary lithium battery), and no explosion or open flame occurs. The 2020 Sydney Energy Storage Power station fire accident Analysis report indicates that the system with LiFePO4 battery packs has a thermal diffusion rate 18 minutes slower per module than the ternary lithium solution in high-temperature short circuits, thus guaranteeing a critical response time for the fire protection system. 98% of Tesla’s 2023 Megapack energy storage project battery packs use the LiFePO4 chemistry system, with a 0.003 times accident rate per megawatt-hour (industry average 0.012 times).
Cost-effectiveness and environmental protection features also further enhance its reliability advantages. Whereas the initial cost of LiFePO4 batteries is approximately $110 /kWh ($150 /kWh for lead acid), their overall life cycle cost is a mere $0.02 /kWh per cycle ($0.05 for ternary lithium batteries). Statistics from a South African off-grid solar project show that the lifepo4 battery energy storage system has reduced maintenance costs by 73% over a period of 10 years of operation (a rate of 35 US dollars/kWh per year versus 130 US dollars/kWh) and does not require an active cooling system (working temperature -20℃ to 60℃). With regards to raw materials, lithium iron phosphate does not employ precious metals such as cobalt and nickel (has 0% cobalt against 20% of ternary lithium), lowering the impact of raw material price volatility on it by 58% in 2022 (according to Benchmark Mineral Intelligence figures).
Performance under complex working conditions guarantees its dependability. LiFePO4 batteries operate at 95% efficiency in charge and discharge when in 100% deep discharge (DOD) conditions (80% in lead-acid batteries) and sustain a self-discharge level of less than 3% per month (5-8% in ternary lithium batteries). Tests conducted at the German Ship Research Institute in 2023 have shown that electric ferries with this battery saw only an annual capacity loss of 1.2% (18% for lead-acid batteries) under the harsh North Sea high salt spray conditions (humidty > 90%). Since China Tower Corporation replaced the backup power of its base stations with LiFePO4 batteries in 2019, the failure rate decreased from an average of 4.7 times per station per year to 0.3 times per station, and 1.2 billion yuan per year was saved on operations and maintenance. Apart from that, its voltage platform stability (±0.05V fluctuation of discharge curve) makes the power supply for medical devices more secure – Medtronic’s 2022 report demonstrated that pacemakers equipped with LiFePO4 batteries have less than a 1% deviation in their 10-year utilization period.
Market statistics confirm the universality of the LiFePO4 technology path. Among the world’s battery pack installation volume in 2023, LiFePO4 was 62% (SNE Research data), up 340% from 2020. The third-generation CTP technology of Catl has made the system grouping efficiency 75% (60% for the conventional solution), and the single-charge mileage has surpassed 700 kilometers (calculated by a 60kWh battery pack). In aerospace applications, LiFePO4 batteries were selected as the main power source for NASA’s concept design of a 2024 lunar base due to their resistance to radiation under a vacuum environment (capacity loss < 2% per year) and the ability to start from a very low temperature of -80℃ (rate of capacity retention 68%). In their forecast, Bloomberg New Energy Finance put the figure at 78% of the market share for LiFePO4 batteries by 2030 and that the pace of their technology iteration (at an average annual rate of 7% improvement in energy density) will increasingly shape the energy business landscape.