What is a 26650 LiFePO4 Battery?

The 26650 Lithium Iron Phosphate (LiFePO4) battery, also known as IFR26650, is a model specification for cylindrical lithium batteries. The numbers in the model hold specific meanings: “26” represents the battery’s diameter of 26mm, “65” represents its height of 65mm, and “0” denotes its cylindrical shape. The 26650 LiFePO4 #battery is primarily used in applications such as UPS batteries, AGV/AMR batteries, medical equipment, lead-acid replacement batteries, communication devices, and energy storage.

Structure and Working Principle of 26650 LiFePO4 Battery

The 26650 LiFePO4 battery consists of positive electrode material, negative electrode material, electrolyte, separator, and casing. The positive electrode material utilizes LiFePO4, which offers high safety and long cycle life. The negative electrode material employs graphite, which can intercalate and release lithium ions. The electrolyte serves as the medium between the positive and negative electrodes, facilitating the transportation of lithium ions through an organic solvent and salt mixture. The separator, made of polymer material, is positioned between the positive and negative electrodes to prevent short circuits while allowing ion passage. The casing, typically made of aluminum or steel, provides protection and structural support for the battery.

During the charging process, lithium ions detach from the LiFePO4 cathode, migrate through the electrolyte, traverse the separator, and finally embed themselves into the graphite lattice. During discharging, lithium ions detach from the graphite lattice, enter the electrolyte through the separator, and migrate back to the LiFePO4 cathode, where they are re-embedded into the LiFePO4 lattice.

Parameters of the 26650 Lithium Iron Phosphate Battery

The IFR26650 battery can be categorized into high-rate and high-energy types based on different capacities. The high-rate type includes IFR26650-2500mAh, IFR26650-3000mAh, and IFR26650-3300mAh. The high-energy type includes IFR26650-3600mAh, IFR26650-3800mAh, and IFR26650-4000mAh. These cover the current range of capacities for IFR26650 cells.

Standard voltage of a single IFR26650 cell: 3.2V Height: 65.3±0.3mm Diameter: 26.3±0.2mm AC resistance (1kHz): IFR26650-2500mAh ≤ 6mΩ; IFR26650-3000mAh ≤ 10mΩ; IFR26650-3300mAh ≤ 20mΩ; IFR26650-3600mAh ≤ 20mΩ; IFR26650-3800mAh ≤ 20mΩ; IFR26650-4000mAh ≤ 20mΩ Operating temperature: Charging temperature: 0°C-45°C; Discharging temperature: -20°C-60°C; Storage temperature: -20°C-45°C Cycle life: (2500mAh-3300mAh) (100% DOD) ≥ 3000; (3600mAh-4000mAh) (100% DOD) ≥ 2000

Advantages of the 26650 Lithium Iron Phosphate Battery

The 26650 LiFePO4 battery has a high volumetric energy density. Compared to lead-acid batteries, it offers approximately 1.5 times the energy density, meaning that for the same capacity, the 26650 LiFePO4 battery occupies around 2/3 of the volume of a lead-acid battery.

The 26650 LiFePO4 battery is free of harmful heavy metals, making it safer and more environmentally friendly.

The 26650 LiFePO4 battery has a high cycle life. Under 100% depth of discharge (DOD) conditions, it can endure over 2000 cycles, while IFR26650-2500mAh, IFR26650-3000mAh, and IFR26650-3300mAh can exceed 3000 cycles.

The 26650 LiFePO4 battery exhibits high safety characteristics.