Food grade Battery grade Ferric phosphate CAS:10045-86-0

What is Ferric phosphate? How does it work?

Ferric phosphate, also known as iron phosphate or ferric phosphate, is an iron salt composed of ferric ions and phosphate groups. Its chemical formula is FePO4, and its CAS number is 10045-86-0. It is a white to light pink crystalline powder, almost insoluble in water, and possesses a stable polyanionic structure with an iron-phosphorus-oxygen three-dimensional framework. This structure makes it a key raw material and delithiation framework for lithium iron phosphate (LiFePO4) cathode materials. With its high stability, high safety, and low cost, it has become a core precursor in the fields of power batteries and energy storage batteries.

Basic information : Chinese name: Ferric phosphate (also known as iron phosphate, high-iron phosphate, battery-grade iron phosphate); English name: Ferric phosphate (also known as Iron(III) phosphate); CAS number: 10045-86-0; Molecular formula: FePO4; Molecular weight: 150.82 (186.85 for FePO4·2H2O dihydrate); Melting point: approximately 1000℃; Almost insoluble in water and ethanol, soluble in inorganic acids such as hydrochloric acid and sulfuric acid; Other names: iron phosphate, high-iron phosphate, iron(III) phosphate, etc.

Structurally , lithium iron phosphate (LiFePO4) consists of ferric ions (Fe³⁺) and phosphate ions (PO₄³⁻), with ferric octahedra and phosphorus tetrahedra connected by shared angular oxygen atoms to form a three-dimensional framework. It exists in various crystal forms, including α-quartz-like structures, monoclinic structures, and amorphous morphologies. The most common hydrated form is the dihydrate FePO4·2H₂O. Battery-grade LiFePO4 has higher requirements for purity and crystal form: only precursors with regular crystal forms and low impurity content can synthesize LiFePO4 cathode materials with excellent electrochemical performance.

physical properties , iron phosphate is a white, grayish-white, or light pink crystalline powder; it is almost insoluble in cold water and ethanol, but soluble in inorganic acids such as hydrochloric acid and sulfuric acid; its density is about 2.74-2.87 g/cm³; its melting point is about 1000℃; battery-grade products emphasize powder indicators such as particle size distribution and tap density, and precursors with uniform particle size are beneficial for synthesizing cathode particles with consistent particle size.

Chemically , iron phosphate is a stable trivalent iron salt: iron exists in the trivalent form, is not easily oxidized in air, and is chemically stable; it is almost insoluble in water, but can dissolve in acidic media to participate in synthesis reactions; it reacts with strong bases to form iron hydroxide precipitate; it is heat-resistant and structurally stable during high-temperature synthesis, making it a reliable iron source and framework in the synthesis of lithium iron phosphate cathodes.

Why do ferric phosphates play these roles in battery fields such as power batteries and energy storage batteries? Their mechanisms of action mainly include the following:

The stabilization mechanism of the polyanionic framework : The phosphorus-oxygen tetrahedron and iron-oxygen polyhedron of lithium iron phosphate form a stable three-dimensional framework. The strong covalent bonds make the framework have small volume changes and are not easy to release oxygen during lithium insertion and extraction. This is the structural source of the long cycle life and high safety of lithium iron phosphate batteries.

Iron-based redox mechanism : The Fe³⁺/Fe²⁺ redox couple in the framework provides a reversible redox reaction. During charging and discharging, iron ions repeatedly transform between divalent and trivalent ions, realizing the insertion and extraction of lithium ions. This is the core mechanism for storing and releasing electrical energy in lithium iron phosphate cathodes.

Precursor structure inheritance mechanism : Lithium iron phosphate is synthesized from iron phosphate and lithium source. The crystal form, purity and particle size of the precursor will be inherited into the cathode material. Only a well-ordered iron phosphate precursor can produce lithium iron phosphate with uniform particles and stable performance. This is why battery-grade iron phosphate emphasizes purity and particle size control.

Thermal stability and safety mechanism : The strong covalent bond of phosphate makes it difficult for the material to decompose and produce oxygen even under extreme conditions such as high temperature or overcharge, and it is not easy to cause thermal runaway. Compared with layered oxide cathodes, it is significantly safer, which is the safety basis for lithium iron phosphate batteries to be used for large-scale energy storage.

The economic mechanism of iron resources : Iron is abundant, widely available, and inexpensive, and does not rely on scarce metals such as cobalt and nickel. This makes the raw material cost of lithium iron phosphate batteries low and the supply chain stable, which is the economic basis for its large-scale popularization in the power and energy storage market.

All Uses of Battery-Grade Ferric Phosphate

1.Power Battery Field

lithium iron phosphate cathode material precursor

Lithium iron phosphate, synthesized at high temperatures from lithium sources such as lithium carbonate, is a key raw material for positive electrode materials in power batteries.

Corresponding products: lithium iron phosphate cathode materials, power battery cells, etc.

Electric vehicle power batteries

Long cycle life and high safety support power batteries for passenger cars and commercial vehicles.

Corresponding products: power batteries for passenger vehicles, power batteries for commercial vehicles, etc.

2.Energy storage battery field

Power grid and industrial/commercial energy storage

Large-scale energy storage systems have high requirements for safety and lifespan, making lithium iron phosphate cells the mainstream choice.

Corresponding products: energy storage cells, containerized energy storage systems, industrial and commercial energy storage cabinets, etc.

Residential and Portable Energy Storage

Home energy storage power supplies and portable power stations, balancing safety and lifespan.

Corresponding products: home energy storage batteries, portable power stations, outdoor power supplies, etc.

3.Electric two-wheeled vehicles and special vehicles

Electric two-wheeler battery

Power batteries for electric bicycles and electric motorcycles.

Corresponding products: electric bicycle batteries, electric motorcycle batteries, etc.

Special and engineering vehicles

Batteries for harsh working conditions such as forklifts, AGVs, and mining trucks.

Corresponding products: forklift batteries, AGV batteries, mining vehicle batteries, etc.

4.Other battery application areas

Communication backup power and UPS

Long-life batteries for backup power and uninterruptible power supplies for communication base stations.

Corresponding products: base station backup batteries, UPS batteries, etc.

Ships and Rail Transportation

Energy storage and power batteries for electric ships and rail transit vehicles.

Corresponding products: batteries for electric ships, batteries for rail transit, etc.

Summary

Ferric phosphate (CAS 10045-86-0) is an iron salt composed of trivalent iron ions and phosphate groups. Its three-dimensional iron-phosphorus-oxygen framework ensures structural stability and minimal volume change during lithium insertion/extraction. The Fe³⁺/Fe²⁺ redox couple allows for reversible energy storage and release, and abundant iron resources keep it inexpensive. These three characteristics make it an irreplaceable precursor and delithiation framework for lithium iron phosphate cathode materials. From electric vehicles and electric two-wheelers to grid energy storage, home power supplies, and communication backup power, lithium iron phosphate, with its combined advantages of long cycle life, high safety, and low cost, covers a broad spectrum of power and energy storage applications, and iron phosphate is the starting point for all of this. Understanding its polyanionic framework and iron-based electrochemistry is key to understanding why it has become a core raw material in the era of new energy batteries.