Na3Fe2(PO4)P2O7 (NFPP321) Powder for Na-Ion Battery Cathode, 100-500 g/bottle, CSIBCNFPP321

Na3Fe2(PO4)P2O7 (NFPP321), commonly referred to as sodium iron orthophosphate-pyrophosphate, is one of the most promising and widely studied cathode materials for next-generation Sodium-Ion Batteries (SIBs).

NFPP321 features a unique hybrid polyanionic framework. Its crystal structure is typically characterized by an orthorhombic symmetry (space group Pna2_1). (1) Polyanionic Units: The framework is composed of isolated [{PO4] orthophosphate tetrahedra and corner-sharing [P2O7] pyrophosphate dimers, which link with [FeO6] octahedra. (2) 3D Diffusion Channels: This specific layout creates a highly stable, rigid 3D framework containing large interstitial tunnels. These open channels allow for rapid, isotropic three-dimensional sodium-ion (Na+) intercalation and deintercalation. (3) Minimal Volume Change: Because the polyanionic framework is extremely rigid, it exhibits "zero-strain" or near-zero-strain behavior during cycling, with volume change typically restricted to < 4%. This minimizes particle pulverization and leads to exceptional structural longevity.

NFPP321 operates predominantly on the Fe^{2+} / Fe{3+} redox couple. (1) Theoretical Capacity: ~108 mAh/g (based on the reversible insertion of 2 Na+ ions per formula unit. (2) Operating Voltage: A flat, distinct voltage plateau centered around 3.0 V vs. Na/Na+. This makes it highly compatible with standard non-aqueous electrolytes and safely below the oxidation limit of most solvents. (3) Energy Density: While its theoretical specific capacity is lower than layered transition metal oxides (like P2 or O3-type NaxMO2), its stable voltage profile yields a respectable material-level energy density of ~320 Wh/kg. (4) Intrinsic Safety: Thanks to the strong covalent P-O bonds, oxygen release is tightly locked within the crystal lattice. This gives NFPP superior thermal stability and safety under abuse conditions (e.g., short-circuiting or thermal runaway) compared to oxide-based cathodes.

Part Number	CSIBCNFPP321 (C-SIB-C-NFPP321)
Chemical Formula	Na3Fe2(PO4)P2O7 (Orthorhombic, Pna2_1)
Chemical Composition	Na: 14.01 wt%    Fe: 24.6 wt%    P: 19.2 wt%   C: 1.71 wt%
Particle Size Distribution	D10: 1.02 um,  D50 =6.60 um,  D90: 13.52 um
Tap Density	2.16 g/cm3
Specific Area	8.20 m2/g
pH	10.58
XRD
First Discharging Capacity	Charge: ~115.4 mAh/g Discharge: ~ 103.7 mAh/g (0.1 C, 1.5-3.8 V)
First Columbic Efficiency	89.89%

Notes: (1) Please store the NFPP321 powder in a dry area (glovebox is preferred); (2) The battery powder is highly recommended to be dried at 80-100°C in a vacuum oven for 6-12 h before use.

References: 

1. Y. Cao, et al. A New Polyanion Na3Fe2(PO4)P2O7 Cathode with High Electrochemical Performance for Sodium-Ion Batteries, ACS Energy Lett. 2020, 5, 12, 3788–3796
2. B. Zhang, et al. Heterovalent Chromium-Doped Na3Fe2(PO4)P2O7 Cathode Material with Superior Rate and Stability Performance for Sodium-Ion Storage, ACS Sustainable Chem. Eng. 2023, 11, 27, 10083–10094